Hello out there-
this is my first post, my first Harley. Bought it new in April 04 and have 5400 miles now in December, only riding on weekends- and the rare occasion I dont need my skillsaw, air compressor, nailgun, saw horses and truck on the job that day.
After having dealer- provided service up till now (including oil changes), I tackled the 5000mi service my self. I'm confident in my mechanical skills and tired of paying thru the nose for glorified lube jobs. However, I lack experience with motor issues. The question is this- my bike wants to diesel when I shut it off mabey 80% of the time. I live inner-city so a lot of stop and go on the way home from rides out in the country. Am I overheating?
This is Seattle where its usually 60F. Thanks for any advise.

Sounds like your running a little lean in the carb mixture. What elevation are you at. Oh...Seatle....well still sounds like carb mixture is too lean. The only way to fix that is to remove the carb and rejet or just maybe drill out the idle screw plug and reset the idle mixture. Actually the easiest thing to check for now would be your ignition timing. Mine was 4 degrees off right from the factory! Of course your idle mixture setting could not have been set right either. The best thing to do is buy a factory repair manual and start reading it. It has a lot of info that will help you in diagnosing many problems and fixing them too.

Isn't the bike still under waranty? When the temperature gets cold the air gets denser and therefore your carb will lean out and oxygen to fuel ratio will be screwed up. The engines are supposed to be set to run their best at standard temperature and pressure. that is 60 dregress farenheit and 14.7 psi (sea level)
You are very close to there and it is dieseling. I would suspect the factory didn't set your engine properly. I would take it back and in the process get the manual and read about how to set these things yourself. In the future it will come in handy.

He can't adjust his timing if it's an 04 or 05. Lean condition sounds about right. I agree, try a rejet first. Also check your plugs and see what color they are.

No Kidding! Isn't there any timign adjustment on the '04's?

plugs look medium grey, no carbon

Sounds good to me. White chalky is your limit. HMMMM maybe your idle mixture is all that has to be set. Your plugs will reflect how the engine is running while under way and not neccessarilly how it is running at idle. The only other thing is timing and now I find out it can't be set. I can't imagine why but I haven't had the occasion to look at the '04's ignition system yet.

The 04-05's use a crank position sensor and the timing is built into the module. He could get an aftermarket module if he wanted.

Ya but isn't the crank positioning sensor moveable like the earlier ones? This is how you set the timing on my '97. It has a crank positioning snesor too. But mine is moveable.

Huh? The CPS is in the case at the front of the motor near the where the oil filter is. There is no more ignition in the nosecone on the cam cover. It is all done in the module now. This is an 04-05 cam cover.

Oh Okay! Then what do you suspect his problem could be? His plugs are grey. That does not indicate a lean running condition unless it is just his idle mixture that is out if wack. What do you think? Or could his ignition module be screwing up?

I shut the bike off with the key instead of the switch- that has nothig to do with it huh? Sometimes I get a burp of oily air from the A/C at shut off. Idle speed increases the longer I'm in the stop and go and the dieseling is worse the hotter (faster) it is at idle when I shut down. Like I said I'm new to HD.

You could have some carbon on the pistons which may cause hot spots(unlikely). In some occasions when your bike runs hot from city traffic, these hot spots can cause a false ignition. It is had to tell what your problem may be, although I would use the switch instead of the key. Also try a rejet on the carb anyway. Have you done pipes or an SE ac kit or anything like that? If it continues take it to the dealer. It's still under warranty and you can cause damage if it continues.

low octane garbage gas can cause runon too try some fresh high octane gas

Okay the colder the air outside the more the carb will COUGH. That is called "the Harley Cough" or "Sneeze". It is the result of tight EPA standards imosed on the manufacturers. The colder the air the more it will cough back through the carb. You probably noticed it when sitting at a light and then trying to pull away. I suspect that your Idle mixture screw needs to be turned out a little. That means you have to remove the carb and underneath it you will find a plugged hole that has your idle mixture screw under it. It is sealed at the factory so you won't mess with it but eventually every one does in order to solve their lean idle problems. I think that this is your problem.

Oh the key or the switch makes no difference. They both shut off the ignition to stop the engine.

Didn't even think of crappy gas. :headb

I suspect he needs to start buying 91 octane and see if the problem goes away. I don't know this for a fact bu I would bet that lower octane fuel could be one source of the problem. Cheap fix.

this forum is great!
I allways use shell gas (station is on the corner of my block and I hav a shell CC). I have tried 92 octane, 89 octane but mostly use 87 as per the owners manual. The octane rise seems to make the diesel at shut off worse, and it seems to run better on 87 as far as throttle response. I have been stalling on pipes and engine mods to maintain my warranty status. My local dealer didnt seem too interested in investigating the dieseling saying "I couldn't get it to do that". It runs great (as far as I can tell) otherwise. I hope no damage is being caused. I've learned to pop the clutch when I shut down- front wheel against solid object to keep from lurching to stop the chug chug chug. Should I try the Dealer again? Anyone else have their 883 diesel.

Ya I never even considered that. I've never bought anything else but premiun 91 or higher octane. I remember that my manual says I can run on 87 regular but that just isn't true.

The Manual says to use 87 for the XL883

Garbage! Start using 91 or higher. don't change anything or adjust anything till you try the highr octane. Octane in fuel slows the burn. The higher the octane rating the more controlled the fule burn. This prevents pinging in your cylinders on acceleration and it also prevents run on when you shut it down. So go to the higher octane for a few tanks before doing anything else and see if your problem doesn't go away.

I will most definetly do that!
What would be the inspiration for the engineers or technical writers at the Motor Company to reccomend the wrong fuel? EPA standards or some such ____?

Yup other than that I don't know. I suspect that they would like nothing more than to recommend that you make your bike breath and give it fuel so that it will put out the kind of performance that the engine is so capable of doing. Unfortunately the old ladies in the EPA just want you to dress like PEE WEE Herman and ride around at 30 mph with your safety vest and full face helmut on.

Mine will run on 2-4 revolutions and fart sometimes if I have recently bliped the throttle and not let her idle back down before hitting the kill switch. I try not to do this but sometimes just can't resist, I love the rumble. Just make sure you let her idle back down/burn iff that excess fuel ya just pumped in there. Maybe you don't do this but sometimes it is the real simple things we tend to overlook. I was worse when the bike was new to me. Also the differanc in cost for 87 over 89-91 octain is negligable for 3 gal. Even before the conversion I went with the 91 just for peace of mind. After all my baby deserves the best

Take bike back to dealer because it is UNDER WARRANTY
and have them fix it. Under warranty means they will fix it
for FREE :headbang for the first two years because it
is your given right as a consumer for the motor company
to stand behind there product.

IT sounds to me like it maybe a timing issue, which will cause the
dieseling affect that you are talking about. Also spend the money
on high octane fuel once the timing issue is resolved when you get
the bike back from the dealer.

G'day

Dieseling or run on, is usually caused by carbon deposits.

It is often from a combination of issues rather than just one.

Some contributing factors are poor fuel quality, getting too hot in traffic, running too rich, babying the bike, too HIGH an octane can also contribute if the compression is not high enough.

Give the bike a good hard run and clean all the carbon out and experiment a bit with different fuels in your area.

Too High An Octane? Explain that one. His plugs are gray in colour that is not too rich. That to me is perfect for a stock bike. No?

G'day Skooter

While it's admirable that you're trying to help.... Incorrect advice is often worse than no advice.

Please limit your answers to areas that you have actual knowledge, as the people coming in here looking for answers often have limited knowledge of sporties and if they read it here they may believe it...not good if that advice is incorrect.

I'll try to pay attention to that when the rain lets up and I get back on. Its not so much that its wet- it's the 7 3/4 of daylight this time of year. But seriously, The bikes running real good now that it's good and broken in and it seems even louder now-even with the stock pipes on. I'll spring for the hi-test in the spring.

Forget the timing ... Even an SE ignition module will not alter your stock timing curve except at wide open throttle.

1. Take the stock #42 slow jet out of the carb and install a #45

2. Remove the idle mixture screw anti-tamper plug, and set the idle mixture screw out to 2 1/2 turns.

3. Then run the engine at full throttle up to the 5,800 rev limiter in 1st, 2nd, and 3rd a couple of times. That will take care of any carbon build-up that's acumulated from all your stop and go driving.

Mission Acomplished .... You have nothing else to do ...

AtA BOY. Stevo you have to explain the low octane to me and to others who have said the same thing. We are all trying to help and if our views differ than clarifying rather than just critcizing would be better don't you think!

His plugs are grey?????? AT what engine speeds and throttle openings are they grey?????

If the octane is too high for the compression it sometimes doesn't burn properly and can leave carbon deposits. Seems more prevalent on bikes that are run softly.

I have had customers bikes that I have fixed dieseling problems by going to a LOWER octane fuel......not common, I'll agree....but these new sporties have a fixed ignition advance, so fuel octane is more critical due to the inability to adjust said ignition

Turbota- Does your 04 overheat in the hot climate? Not knowing any better I attribute the dieseling to the motor getting too hot (albeit cool ambient temps here)

G'day Toothy

When is it doing it or when does it seem worse????

What is the recommended octaine on a 1200 04?

G'day Skoot

A lower octane fuel will often burn completley as the temp in the cylinder is high enough for complete combustion.

As I understand this....due to the slower burn of higher octane fuel the the piston will be further down the stroke than with the low octane fuel, this larger volume can cause an incomplete burn and deposits can be left.

The problem with low octane fuel is that it often has more impuities in it and this causes a lot of problems too.

We have a number of fuel supliers over here in OZ..a couple a very good and some others will almost always give engine problems such as running on or poor idle or high speed misses.

Yes! Stevo now I understand! Okay at a 9:1 compression ratio which is stock on my 1200 the Higher octane ran much better than regular 87. Most guys have found this out on theirs too. That's why we reccommended he do the same.

AT the end of the day ...experiment with fuels that are supplied in YOUR area and whatever works best then stick with it......

There is far too many variables to have a hard and fast rule...what works well in one town in some bikes may be attrocious in another

Mine don't overheat in Arizona summertime ... I guess if I let it idle long enough in the summer, it would continue to heat soak .. But under normal cruise and stop and go combo ... I don't have a problem.

If your not using premium fuel, you really should be. The rear cylinder will get hot after lots of idle time. Premium won't stop it from getting hot, but it's less suspeptable (that ain't spelled right) to detonation. Anyway, use premium in the bike.

That run-on (dieseling) is caused by a lean condition and hot spots from carbon deposits. (basicely a combo of the two)

If you live in a small town or out in the suburbs and fill up from a servo that doesn't go thru much fuel then higher octane may be better.

If you are filling up in a high turnover servo then a lower octane may be fine as it will be fresher and the octane rating will not have dropped as much

The 883 is not a high revving engine by todays standards (6200 rpm) so would the higher octane fuel still have the problem of not burning completely than compared to a much higher revving japanese motorcycle engine (14000 rpm)?

Stevo-
It diesels when i shut off after riding thru the city to get to my house from the freeway. Also after riding around town. The scenerio is this, warm up bike on Saturday am. Stop at Shell station shut off bike. start bike no prob, its allready warmed up. head for the freeway thru 10 minutes of stop and go- bike sounds great nice potato potato, on freeway at 70 mph nice ride, get off freeway head to country road destination, enjoy ride, stop at destination, shut bike off and chuga chuga chuga. As I ride thru stop and go the idle picks up (I have no tach) from nice potato potato to kinda like an inline 4- you know blender set on grate- whirr whirrr. this is when I get dieseling at shut down.

Yea, I realize that all fuels are not created equal and vary from location to location but is the factory recommondation for 91 octane?

aparently it is 87 octane. it is on my '97 and every other EVO harley I know of

Like I said ... Riched up the already lean stock idle with a #45 slow jet ... set the idle mixture screw out to around 2 1/2 turns ... fill it with premium gas ... and run it up to the rev limiter in 1st, 2nd, and 3rd a couple of times ... Your run-on will be history.

Save the regular gas for your lawnmower

Turbota- Does your 04 overheat in the hot climate? Not knowing any better I attribute the dieseling to the motor getting too hot (albeit cool ambient temps here)

Alot of this maybe bad riding habits, lugging the motor is a no-
no, which maybe helping motor run hot. Switch to a good
synthetic oil which will help lower running temps. Mobil-1
15w50 is a good choice, mostly run by alot of people on this forum.
I use it and it will reduce temps by 10-25 degrees during hot
months and when you are caught in god awfull traffic.

The sportster has to be ridden like you just stole out of ghetto
somewhere in East LA. :lolsign

Thanks Skooter, didn't realize it was 87. Been doin' 91 and with the freeway speeds of 80+ it's been great.

:lmaorof :rolllaugh "The sportster has to be ridden like you just stole out of ghetto
somewhere in East LA." I like it :laugh

Most everyone I know goes uses 91 or higher and say they get better results. Mine used to ping like crazy on 87 with the factory timing settings. So I went to premium and it went away.

Oh here we go ...put SYN in and everything will be better.... :rolleyes:

As Turbo said up one on the pilot is usually a good starting point.

the amount of turns out is dependant on YOUR vehicle...the reason that that needle is adjustable is because NOT EVERY BIKE IS THE SAME

The fact that it's doin it AFTER a bit of a run tends to say it's more a fuel type issue or a needle height propblem.

I'd experiment with different fuels before adjusting anything if the bike is running fine other than the dieseling

Thanks Stevo. I can imagine that these forums can be frustrating when your used to working on engines and your communicating with those that don't have as much experience.

G'day Skoot


Yeah.....This internet is a 2 edged sword...which is why I get cranky on occasions with incorrect info....

people do a search for info and then find something and try and it MUST be right because they read it somewhere. Especially if it's a respected site that is right MOST of the time (yeah we ALL get it wrong on occasions, but that's life we're human)

Infernal combustion engines are at the same time simple and complicated.
The systems at play in their running is WAAAAAAAAYYYY over most peoples heads, mine included.

One of the reasons carbies have changable jets is because NO TWO BIKES ARE IDENTICAL.

That's why it's called "tuning" in the same vein as you adjust your guitar strings and the weather can affect them, so can the weather and many other things affect the tuning of a vehicle.


To give an example that i've done just recently....I've fitted an HD Keihen carby to a Suzuki 1500 Intruder.

Sounds easy ... NOT

I fabricated a new manifold as it had dual downdrafts on it before.
This gave a longer intake runner length which changes the harmonic timing in the system.
A K&N filter of the apporopriate size was chosen and an adapter machined up.
The whole thing was fitted, modified choke and throttle cables of course.
The electric decompressor had to be relocated and redesigned.
The throttle position sensor had to be modified
THEN I start tuning.

I found that the manifold vacuum is higher and pulse strength stronger than on an HD so i had to extend the spring as the slide was running too high.
It runs an electric fuel pump at a higher pressure than the gravity feed on an HD so I had to change float height to compensate.

I've got it running better with more power, throttle response and the best economy he has every had out of the bike.

Now ya don't do that by just whacking in a bigger pilot and running a 2 1/2 turns out.



My sporty runs a 48 pilot at 1 1/4 - 1 3/4 at sea level depending on weather and a 45 pilot if I'm up in the mountains in summer. 48 pilot in the mountains in winter tho.

Stevo ...

Your right, all these motors are different, fuel availability is different from region to region, and environmantal conditions are different (not only the fixed altitude the bike operates at, but the density altitude changes with baro press, temp, and humidity)

I just advised him to put in a slightly bigger pilot jet, set the idle mixture screw to something in the middle (2 1/2 turns), use premium fuel, and blow the carbon out of the bike for starters ..... That will at least get him in the ballpark and [should] elliminate the dieseling he has now.

Dyno time with someone that understands tuning certainly can fine tune everything after that.

Is (has) the dieseling done damage over the 5K mi so far? Maybe I need to go after some warranty work. I followed break-in by the book and had all service done by dealer (minus this last time). This bikes my toy, but I want to protect my money in it. I labored over what first bike to buy, so far I'm glad bought the sporty.

It is humourous though. In reviewing the posts one can see that there are basically two solutions to this problem. One solution is saying that dieseling is caused by too lean a mixture and nor high enough octane. the other solution is suggesting too high an octane and too rich a setting that is the cause of dieseling. Intersting because if you reflect on them both make some sense.

Yet I suffered from the "COUGH" and dieseling on my stock set up for a long time. when i did my top end I chose to stick with the stock 9:1 compression yet increased the flow with SE AC with K&N filter along with straight pipes with power cones. I went with the reccomendations of two mechanics to up the low speed from stock 40 to 45 and went with thr Yost power tube master kit and went from stock 170 main to 175 and played witht he needles and different height settings (this took a lot of playing around to get it right). Ultimately I'm running more fuel at a richer setting (chalky tan colured plugs as opposed to chalky white with some glazing which was too lean). My coughing doesn't occur anymore and neither does my run on or dieseling. In real cold weather close to freezing I still experience poping in my exhaust when I back off on the throttle which isn't there on hot days. But all in all my bike is running and performing better than the stock set up. I'm still running the stock ignition specs and using 91 or higher octane. Anythingl ower and my bike runs like crap.

I have been told bu many that every engine is different and requires some playing to get it right especially modifying an engine would definetely require very close attention to what is going on.

I don't think dieseling has damaged a thing. In fact, I would place money on it. And I doubt the dealer will attempt to fix the dieseling either if you bring it to them.

Richen up that EPA lean idle condition you have a little, use premium gas from now on, and run it up at full throttle to the rev limiter a couple of times ... Fini ... And don't worry about it anymore.

Just my opinion ....

I can't imagine that dieseling is doing your engine any good. So finding the solution would be better than just letting it continue. I don't think that it can be too hard to solve since we're dealing with a stock manufactured engine as oposed to one that has undergone major modifications.

There now Turbota and I disagree on this but I agree with him about your idle mixture because thatis what the harley mechanic told me to do as well before I went withall the other changes That I did.

Where's stevo on this one?

I think this thread has pretty well already played itself out

This is the problem with tuning over the net and one of the reaons I stay out of most of these discussions and yet I have more experiance than most in this area.

my workshop is mainly performance engines and tuning, I see a lot of different problems and not all of them require the same soloution.

Most Hd's like up 1 - 2 jets on the pilot
pilot mixture screw whever it wants to be but it it runs closer to correct with less than a turn the go down one pilot size and if ya need more than 3 1/2 then go up a pilot size.
Needles ..keep the stock one and sometimes raise the needle a touch
rarely drill the hole in the slide out unless you have MAJOR engine work done.
Mains are rarely changed from stock.

there are tooooooo many variables to give acurate spot on for every situation advice over the internet WITHOUT asking a LOT of questions to determine the conditions of each particular case.

Anyone who says "just do this and it will fix it" is overly simplifying the situation and is only going to be right on so many occasions and will be WAAAAAY wrong on others.

The more one learns about engines and the syatems involved the less one "knows"

:laugh could be but it was very interesting. Especially with all the differing opinions. I use Synthetic Oil in my bike too. maybe that's why it runs so good!

:laugh :laugh

Dieseling can damage your engine. in the same way as "pinging" can.

it is no good for the bottom end and hammers the rod into the bearings

I'll try my dealer again, he didnt give it much cred last time. Thanks, bros.

OH YES! Now I definately agree with you on that one. There is nothiin like getting real close to an engine before you can recomend a sure fix. So the real advice would be to have him take his bike to a qualified tech and have him look it over and ride it himself.

I USE 89 OCTANE IN TEMPS BELOW 60 DEG.F AND ABOVE THAT MY BEAST GETS 92 OCTANE. IF I DONT BEAST WILL DIESEL. EVERYONE I KNOW THAT RIDES A SPORTSTER DOES THIS OUT HERE. :smoke

This thread has been pretty humorous. If nothing else I've learned not to just accept one answer to any question. Ther most likely will be a couple things that you need to try to solve any one problem.

I USE 89 OCTANE IN TEMPS BELOW 60 DEG.F AND ABOVE THAT MY BEAST GETS 92 OCTANE. IF I DONT BEAST WILL DIESEL. EVERYONE I KNOW THAT RIDES A SPORTSTER DOES THIS OUT HERE. :smokeI especially got a kick out of beast1's experience since mine is just the opposite. During the warmer summer my 883 loves to run on 87 octane, but once it starts to drop below 55*F I need to boost the octane to help with the coughing.

Gary

Dieseling can damage your engine. in the same way as "pinging" can.

it is no good for the bottom end and hammers the rod into the bearings
If you used SYN it would SKATE instead of hammering
the rod into the bearings. :yikes
Oh here we go.... put SYN in and everything will be better :cry1

AHHHH Gary

there are no problems...only solutions we have not yet found........

The problem is to correctly define the problem, very problematic even at the best of times.

The more complex a system the more things can give similar if not identical symptoms.

With dieseling it's caused by carbon or other deposits glowing and igniting the fuel charge.
The reason this particular problem may have many solutions is because the problem needs a number of things to occur before it will present itself.

We need the right (or wrong) deposits and heat

Many things can cause the carbon/deposits, so we need to experiment to work out what is causing the deposits....this is why I recomend trying different fuels first, 'cos I like the easy way....

Guys, this has to be one of the longest pots I have seen in this forum... a record?

Stevo is correct here, run on is normally caused by deposits glowing when they should not and acting like a 'diesel glow plug'. It can also be caused by sharp surfaces usually found on badly machined spark plug holes leaving swarf hanging into the combustion chamber, or by sharp edges on valve pocket cutaways, even sharp edges on valves, all glowing too hot when they should not glow at all.

I would try the higher octane fuel first, as this is easy and may fix the symptoms. We can only get 93 octane or higher here in the UK so the agument of 87 vis 91 octane is irrelevent!

This may help, but judging by what I have read here the bike in question is run softly and probably has built up deposits that need to be removed by a 'de-coke'. A fast run or two may, or may not remove or burn off the deposits in the engine. De-cokes are not done frequently nowadays, but was always needing to be done in the past every 25K miles or less. Modern fuel and oil together with closer machining tolerances should have made this a thing of the past....until extended milage has been covered.

If this bike is still under warrant take it back to the dealer!!! Get them to sort this out, for free. An 04 bike should not run on like that!

Personally I'd lift the heads and see what is causing this.....if all else fails.

Mixture seems OK with the colour of plug mentioned, light tan would be better, meaning a bit richer may help ( we need to be careful here cos plug readings need to be done carefully at set throttle openings). Better to check this on a dyno so we can measure the mixture strength directly.

We assume ignition timing is correct cos we cant adjust it? Get it checked, too retarded can make an engine very warm and cause run-on, too advanced and we get pinking and in this case we don't get pinking.

As I said, take it to the dealer!

Whiffi.

Whiffi's cool! :tour

Yeah Whiff

We used ta have the same problem and also pre-ignition on the old mini engines when we bombed 'em.

Had to knock the protrusion off in the combustion chamber as it would glow and cause said symptoms.

High octane fuel in a low compression vehicle gives the same effect as a retarded ignition too...slower burn

As stated too many variables, try different fuels first, then see what happens


AND RIDE HARD......

Mine has run on a few times over the years, only after I've been putt putting around town for a while, part of it was fuel problems as the fuel companies took the lead out and put other additives in.