The Sportster and Buell Motorcycle Forum - The XLFORUM®

The Sportster and Buell Motorcycle Forum - The XLFORUM® (http://xlforum.net/forums/index.php)
-   Ironhead Sportster Motorcycle Talk (1957-1985) (http://xlforum.net/forums/forumdisplay.php?f=7)
-   -   Ironhead 69 xlch won’t start (http://xlforum.net/forums/showthread.php?t=2079722)

rykk69 5th July 2021 02:20

69 xlch won’t start
 
Hi folks- new member here. Bought a 69 xlch in Dec. It was not running when I bought it but seemed in decent condition. Pulled the motor and rebuilt top end, new rings. Sent magneto to joe hunt for rebuild. Put everything into a Flyrite choppers gunslinger hard tail frame and have been trying to get it started last two weekends. It has a vintage Mikuni vm38-9 carb. Last weekend I got it to pop a couple times. Pulled the plugs and grounded and kicked in the dark- I am getting a spark. I sprayed gas into carb throat and got it to pop a couple times, then almost start (had throttle held wide open)- ran for like 1 second. I pulled the carb and took apart, cleaned checked everything- seems fine. Tried again today, adding some starting fluid into the mix. Same thing. Rechecked magneto timing- seems correct. It pops and seems to pop out of the carb when it “almost” starts. I did have the cam gears out, but carefully followed installation instructions.

I am not sure what to try next. I know there is lots of knowledge and info here but sometimes hard to figure out what’s relevant for a magneto kick only xlch. Any help would be very much appreciated!

doodah man 5th July 2021 04:41

Still have the left grip advance/retard control? Is the enrichener lever pushed down all the way on the carb when kicking? Jack the throttle slide screw in a bit (faster idle) and see if that helps, if it’s too fast an idle you can always dial it back down.

kitabel 5th July 2021 04:51

Don't touch the throttle when kicking.

doodah man 5th July 2021 04:59

Quote:

Originally Posted by kitabel (Post 5903205)
Don't touch the throttle when kicking.

+1 the further you open the throttle slide, the less it meters through the starting circuit.

Whitewalls 5th July 2021 07:34

This brings back memories. I had a very similar problem on my bikes first start after rebuild. My dumb ass didnt have quite enough gas in the tank. The fuel level was just barely below the draw tube in the tank.
Disconnect the fuel inlet hose at the carburetor and hold it over a container then open your petcock to make sure you have good flow.

Also. I know everyone says to not touch the throttle when starting a VM38-9 with the choke/enricher on. When I have a difficult cold start after many kicks I hold the throttle open about 1/4 turn and it usually starts.

rykk69 5th July 2021 17:28

Thanks for responses. No, I don’t have the left side advance control, but have tried manually rotating the magneto to advanced position.

First thing I checked was fuel flow from tank - it is good.

I tried with enrichener down, not touching throttle. Played with idle and air screw. No joy.

Also, I did check intake manifold o-rings - seem ok. I am tempted to buy a new Mikuni vm38-9 (see them online for $125-$150) and throw it on.

Iron Mike 5th July 2021 17:47

If the idle speed screw is cranked in too far, you will not pull fuel through the enrichener circuit on initial prime kicks. That will hold the slide up too far and allow air through Venturi and not pull through circuit.
Try backing speed screw all the way out on prime kicks, to allow a full pull on enrichener. Three good primes with no throttle or ign. Then when fuel is primed, use throttle to raise slide 1/4 throttle.
If it coughs, restart procedure.
Sounds like your not getting enough fuel, if all else is correct.

brucstoudt 5th July 2021 22:35

rotating the magneto to the advanced position will not help it start.popping through the carb is a sign of being advanced. it will start easier slightly retarded.Mike mentioned prime kicks,are you familiar with the procedure?

Ferrous Head 5th July 2021 23:59

Back to basics.

3 things needed to start this engine.
1. enough compression
2. a spark at the right time
3. correct air/fuel mixture going in.

1. we assume with a rebuilt top end ( and you can feel it when you kick it) that no. 1 is not the problem.
2. I check for this problem with starter spray - just like you did. A full 2 second spray into the open throat should allow the engine to start and run for 1-2 seconds.
3. I have discovered a quick and simple sanity check for this. I bought a $59 Chinese "fake" S&S Shorty from eBay. I can substitute for any suspect carb and it tells me if that's the problem.

Two caveats.

1. These engines can and will "nearly" run with the timing out. Even by 360 degrees.
Just double check that your on compression on the front cylinder and using the narrow lobe on the magneto cam.

2. I check both cylinder with a compression gauge. This is the first tool I reach for as it will tell you so much, quickly. I know you rebuilt the top end but a check on your work can be done this way. Also tells you the push rods are correctly adjusted and your cam timing is good.

Of course, all of this is only my opinion, others may disagree.

Whitewalls 6th July 2021 00:22

My experience with the VM38-9 is it seems pretty fool proof. My bike typically starts within 3 kicks cold and 1 kick warm or hot.
I have never used prime kicks. My idle screw is turned in tight at cold start and I adjust it after warm up. My air screw is about 1 1/2 turns out.
As Brucsstoudt says it sounds like it's not getting fuel if all else is correct.

rykk69 6th July 2021 00:49

Thanks all. I was going to take the day off and let the bruises on my legs and blisters on my hands have a break, but I can’t help but keep trying.

So I meant retarded on the magneto, turned towards engine. Interestingly, it seems more prone to light when it is rotated other way, which made me recheck timing, which does seem correct. Front intake just closed, then rotate until line shows up. Narrow lobe just starting to open.

I did do a compression test- getting about 95 lbs front and rear with 3 kicks.

I will try priming kicks with magneto grounded.

rykk69 6th July 2021 01:12

No luck with priming kicks. Spraying starting fluid into carb throat I can get to pop, then run for about 2 sec, but that’s it. I think I will order a new Mikuni vm38-9, unless anyone can recommend a better option.

I think it might be time to jump on my Ducati and clear my head…

Ferrous Head 6th July 2021 01:30

Indicating there's no fuel reaching the carb.

Remove the bottom drain plug. Turn on the fuel tap and see if you have fuel coming out.

My guess is stuck needle/seat.

If you get nothing try a sharp rap with a plastic screw driver handle on the float bowl. Sometimes that's enough to loosen them.

rykk69 6th July 2021 02:44

Thanks ferrous head! I did check float and bowl was full of gas. I have ordered a new Mikuni carb. Should arrive in time to try again next weekend.

In the meantime I might recheck valve adjustment.

doodah man 6th July 2021 03:28

Next time you attempt to kick it, remove a plug after your prime kicks and see if it’s wet with gas. If this bike has sat for a while, it might be time well spent to dismantle the carb and soak all of the metal parts in a can of berryman’s chem dip or similar, rinse with boiling hot water.

Medyo Bastos 6th July 2021 04:35

How old is the fuel?


Sent from my iPhone using Tapatalk

davixlrtt 6th July 2021 23:27

Quote:

Originally Posted by Medyo Bastos (Post 5903426)
How old is the fuel?

My CH sat for nearly 4 months over the winter and would only start after I replaced the fuel.
…….Davi.

rykk69 6th July 2021 23:53

So I did disassemble carb and soak overnight in berrymans, checked and blew out all passages. No difference.

It is a new build, new tank, new gas.

I did pull plugs and they are not wet.

New carb should arrive Friday.

rejeanprimeau 7th July 2021 00:42

What your sparkplugs gap at ???

kitabel 7th July 2021 00:50

Read any Mikuni manual.
They don't have chokes, and prime kicks do not work.
Do what the manufacturer says: depress the enrichment lever and kick it through. A cold engine will run at fast idle without touching the throttle.
Lower the idle speed screw 1 turn before you try again, and take your hand off the throttle.

rykk69 7th July 2021 05:09

plugs are at spec for magneto, 0.020 I think.

Yes, I have read all the manuals for the VM38. Tried everything.

Ferrous Head 7th July 2021 06:30

Quote:

I did pull plugs and they are not wet.
Still indicating the engine isn't getting fuel.

So I suspect a carb swap will sort it out.

Still, have to wonder why no fuel is getting to the engine.

Basically has to be something wrong in the idle circuit. Dunno.

GA_Ironhead 7th July 2021 12:29

Lots of guys here have had to clean old carbs multiple times to get them clean.

What plugs?

What wires?

jeffro57 9th July 2021 04:51

I soda blasted a few carbs, always works. here's one is the fuel line getting hot? I had one that the fuel was boiling, had to put an insulator sleeve on it

Whitewalls 9th July 2021 21:31

Quote:

Originally Posted by kitabel (Post 5903581)
Read any Mikuni manual.
They don't have chokes, and prime kicks do not work.
Do what the manufacturer says: depress the enrichment lever and kick it through. A cold engine will run at fast idle without touching the throttle.
Lower the idle speed screw 1 turn before you try again, and take your hand off the throttle.

Tomato potato. Mikuni calls it a choke. It may not be a traditional choke in the sense that it doesn't turn a butterfly to block air flow but Minuni stamps the lever with the word CHOKE not enricher.

brucstoudt 9th July 2021 22:21

Quote:

Originally Posted by kitabel (Post 5903581)
Read any Mikuni manual.
They don't have chokes, and prime kicks do not work.

???? prime kicks work great on my Yamaha 400 2 stroke with factory mikuni carb.fastest easiest way to start it.the previous owner gave me the procedure.

RicThompson 9th July 2021 22:22

Magneto ignition works best with non resistor copper core plug wires and non resistor spark plugs. I use Autolite copper core 4316's.
Ensure that you do not have a tight pushrod. All 4 should roll between fingers freely at bottom.
Set points to 12 and plugs to 18. Put the timing line between center and rear of hole. place cellophane between points turn mag until narrow lobe opens points enough for cellophane to slip then lock it down.
Remove air cleaner. Have someone hold palm of hand over carb throat, kick the engine over 2-3 times, remove hand from carb unkill mag and start.
If that don't work find a big hill.

rykk69 10th July 2021 05:40

Thanks for support! New copper plug wires from lowbrow. Champion plugs to spec (can’t remember off hand the number). Plugs and points to spec (.020 and .015). New carb arrives tomorrow- hope for the best!

Doc308 10th July 2021 16:22

Are you sure that the timing isn't 180 degrees out? I always se Mikunis--love' em. However, I bought one one time on Ebay from a private seller and had starting problems. Turned out that a tiny jet was missing in one f thie tiny holes in the fron of the carb.

rykk69 10th July 2021 18:10

@ Doc308 I don’t believe it is out 180, but how can I be entirely sure? Would like to rule that out! I have heard to use thumb test to make sure front cylinder is under compression anything else?

Iron Mike 10th July 2021 18:15

When front valves are closed, should be approaching small lobe on mag.

Doc308 10th July 2021 19:53

Yes--Expose the front intake pushrod. While you rotate the engine, watch for that lifter to drop. Once it has dropped, very slowly rotate the engine and look for your flywheel timing mark in the hole. It should come up very shortly after that pushrod/ lifter drops. Another simple way is to place a straw into the front spark plug hole and when it rises upward , you are on the compression stroke. Always time the bike on the front cylinder compression stroke.

brucstoudt 10th July 2021 22:04

Quote:

Originally Posted by Doc308 (Post 5904185)
Another simple way is to place a straw into the front spark plug hole and when it rises upward , you are on the compression stroke. Always time the bike on the front cylinder compression stroke.

it's only on the compression stroke every other revolution.that's why it's best to watch the front intake lifter close. ;)

rykk69 10th July 2021 22:48

Ok, thanks! That is the process I have followed- watch intake lifter to close, then rotate until timing mark appears.

Damn usps! Paid $20 extra for two day priority shipping on the carb and now they just say it is delayed. Don’t even know where it is.

Medyo Bastos 10th July 2021 22:49

I stopped using usps for that very reason.


Sent from my iPhone using Tapatalk

rykk69 13th July 2021 07:48

Update- installed new Mikuni vm38-9 carb today and she started! Still took a few kicks, and restarting was hard. Need to figure out what works. Air screw is 1 1/2 turns out. Restart once hot seemed to need prime kicks, but then partially open throttle. Any tips on cold, warm, hot starting with Mikuni and magneto appreciated!

Ok, next issue is clutch is stuck. I reassembled according to manual, adjusted, but plates seem stuck. I did not disassemble clutch when I had primary cover off. It looked very clean, so left it alone. I thought maybe once it got started and warmed up the clutch might free up, but not so far. I read somewhere that one option to try would be to place front wheel against a wall then kick into gear, and plates may free up. Any tips with this?

Ferrous Head 13th July 2021 08:28

This is a 69 CH. right ?

When you pull the clutch in, can you feel the resistance and the travel ? Id there free play at the clutch lever ? This might just be adjustment.

If you put the bike in gear and pull the clutch in you should be able to free the clutch with some vigorous back and forth motion on the bike.

The plates will be sticky if the engine has been sitting for some time and oil has seeped in. Technically, it should be a dry clutch and not be a problem.

ryder rick 14th July 2021 16:52

Get the motor warmed up so it wont stall.

Push the bike to get it rolling and drop it into gear.

Shift into second or third, then rapidly open and close the throttle with the clutch lever pulled.

This will unstick the clutch plates.

brucstoudt 14th July 2021 22:37

^^^ this should work fairly well for wet clutch primary models.for dry clutch models if the reason for the sticking is oil soaked friction discs they really should be replaced.or at least cleaned or the sticking can reoccur.

rykk69 15th July 2021 00:30

Yes, ‘69 xlch dry clutch, and yes it has been sitting for at least 2 years. If I can’t get it to free up by Ferrous Head’s suggestion I may pull the primary cover and get into the clutch. I think I read somewhere that if the primary chain is too tight that could cause sticking clutch issues?


All times are GMT +1. The time now is 02:25.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2022, vBulletin Solutions Inc.
XL Forum® - Linson Media LLC