Ignition timing vs vacuum recommendations.

[Jfart]

I have set my 2ki as far retarded as possible on curve 4 (so probably 26 degrees) but at present still get a small amount of pinking as I pull away. I have been experimenting with colder plugs, as the Buell xb motor with a similar compression runs two grades colder plugs (9's vs 7's in NGK spark plugs) and I have heard that traditionally people would go a grade colder with every point higher compression.

Sorry, there’s a lot going on on this thread. A lot of great information that I haven’t seen elsewhere too.

You mention plugs, I’m using the HD 10R12X plugs.

Part of me wonders if what I’m hearing is the piston hitting the plug. Is that a high pitched metallic ping? I’m just running the plugs how they come. Haven’t gapped them and I’m only using the washer that is on the plug. With flat top pistons I wouldn’t think that would be a problem though.

The screaming eagle cnc portages heads come decked .050 I think. My gasket is .030 ( I think is .020 thinner). Between the decked head and the gasket I had to shorten the pushrods. I’m using solid pushrods that are .050 shorter and for a late model evo, prob 04-05. I believe the xb heads are shorter.

Anyone know what kind of washer I could use between the plugs and heads to see if that’s what’s causing the ping? Do local auto parts stores sell them?

[uk_Chap]

Originally Posted by Jfart

I have set my 2ki as far retarded as possible on curve 4 (so probably 26 degrees) but at present still get a small amount of pinking as I pull away. I have been experimenting with colder plugs, as the Buell xb motor with a similar compression runs two grades colder plugs (9's vs 7's in NGK spark plugs) and I have heard that traditionally people would go a grade colder with every point higher compression.

Sorry, there’s a lot going on on this thread. A lot of great information that I haven’t seen elsewhere too.

You mention plugs, I’m using the HD 10R12X plugs.

Part of me wonders if what I’m hearing is the piston hitting the plug. Is that a high pitched metallic ping? I’m just running the plugs how they come. Haven’t gapped them and I’m only using the washer that is on the plug. With flat top pistons I wouldn’t think that would be a problem though.

The screaming eagle cnc portages heads come decked .050 I think. My gasket is .030 ( I think is .020 thinner). Between the decked head and the gasket I had to shorten the pushrods. I’m using solid pushrods that are .050 shorter and for a late model evo, prob 04-05. I believe the xb heads are shorter.

Anyone know what kind of washer I could use between the plugs and heads to see if that’s what’s causing the ping? Do local auto parts stores sell them?

I think its unlikely to be the spark plug hitting the piston, I have had this on my sons 2 stroke and it makes a real racket....you would not run the bike at all with this noise, not even for 1 minute!
If its a constant ticking that changes with revs, it could very well be the rocker shafts turning and a cheap rocker locker kit will sort this out for you as it did for me.

Your right about the XB heads being 50 thou shorter than previous heads and the Screamin Eagle ones another 50 thou shorter again. When I bought my XB heads the guy gave me the newer shorter OEM solid pushrods as well, they all come off a 2007{?} EFI sportster, so I had to make some conversion spacers for the carburettor manifold.

The plug thing I am still evaluating, but if Buell used colder plug with their higher compression version of the XL motor, they did it for a reason.

Again, I will certainly be sure to let you know what works for me or what doesn't.

[Jfart]

Originally Posted by uk_Chap

I think its unlikely to be the spark plug hitting the piston, I have had this on my sons 2 stroke and it makes a real racket....you would not run the bike at all with this noise, not even for 1 minute!
If its a constant ticking that changes with revs, it could very well be the rocker shafts turning and a cheap rocker locker kit will sort this out for you as it did for me.

Your right about the XB heads being 50 thou shorter than previous heads and the Screamin Eagle ones another 50 thou shorter again. When I bought my XB heads the guy gave me the newer shorter OEM solid pushrods as well, they all come off a 2007{?} EFI sportster, so I had to make some conversion spacers for the carburettor manifold.

The plug thing I am still evaluating, but if Buell used colder plug with their higher compression version of the XL motor, they did it for a reason.

Again, I will certainly be sure to let you know what works for me or what doesn't.

That makes me feel better on the spark situation. I think there would be a whiteness mark on the piston and I didn’t see one the three day when I looked at the piston top of the piston.

I just put that 42 jet in my voes hose. Drove around the block. I could hear whining sound on development when the engine brakes. I can’t think of why that would cause a whining sound.

I had just adjusted my drive chain and I’m thinking that May be the cause. I jacked the chain and it’s all 1/2” - 5/8” slack in the chain. A chain too lose wouldn’t cause a whine would it? I’ve heard that a tight chain would. But it presents to be at the correct setting.

Also, when poking a screw driver in the hole at the chain for movement I have more up movement than down movement. Is this normal in your experience?

[uk_Chap]

Originally Posted by Jfart

That makes me feel better on the spark situation. I think there would be a whiteness mark on the piston and I didn’t see one the three day when I looked at the piston top of the piston.

I just put that 42 jet in my voes hose. Drove around the block. I could hear whining sound on development when the engine brakes. I can’t think of why that would cause a whining sound.

I had just adjusted my drive chain and I’m thinking that May be the cause. I jacked the chain and it’s all 1/2” - 5/8” slack in the chain. A chain too lose wouldn’t cause a whine would it? I’ve heard that a tight chain would. But it presents to be at the correct setting.

Also, when poking a screw driver in the hole at the chain for movement I have more up movement than down movement. Is this normal in your experience?

Hi, I run an automatic primary chain tensioner and have done for many years. The primary chain will make a whine, mine does because I have a stronger spring in my automatic tensioner than normal, so yes, it is probably your chain whining.
This isn't necessarily a problem though if your slack measures OK.

if your like me, your listening out for unusual noises and questioning every one of them at the moment more than you would normally.

[Tomcatt]

Originally Posted by uk_Chap

Anyway....I have resealed it after adjusting it to 9 hg and when the silicone sealant is set tomorrow I will take it out for a spin and see what happens.

How's the 9" VOES working?

[uk_Chap]

Originally Posted by Tomcatt

How's the 9" VOES working?

Hi, Well for me it appears to be the ticket.

In the end I didn't manage a particular long ride, however

I think your suggestion of placing a pilot jet in the hose to the VOES got me
70% there, and the raised switching point the other 30%.

The bike feels good and solid, accelerates faster than I should accelerate and no pinking...so all good really.

I did discover another problem, and its one that haunted me years ago.

My bike was originally an 883R with the Screamin Eagle 2 into 1 exhaust. after a couple of years of owning it, the engine started to run like crap and I discovered the silencer (muffler) bracket had broken, and it caused all sorts of exhaust popping and engine rattling...

So about two years ago, I replaced the silencer with an new identical one and the new bracket that came with the new silencer. Yesterday I noticed this new bracket has also started to Break and is allowing the silencer to shake. Its a 99% certainty that this will be causing the remainder of my issues.

I have the old one in the attic that I had welded up and ran with for 15 years or so...I will swap them over and hopefully?!

Anyway, your suggestion re the pilot jet was a massive leap in the right direction and I have to thank you for that.

Thank you :-)

[Tomcatt]

Thx for the feedback! I was thinking you might end up going 7" or 8" to keep the more advanced curve on longer.

[uk_Chap]

Originally Posted by Tomcatt

Thx for the feedback! I was thinking you might end up going 7" or 8" to keep the more advanced curve on longer.

I was already running at 7 Hg, and the pilot jet trick made this better, but not perfect.

I could have tried 8 hg first, but I figured that after watching the vacuum while riding, it was only when pulling away, and also when whacking open the throttle on a roll on, the vacuum really dipped below 10 Hg, so 9Hg wouldn't be seen until less advance was needed.

Also my way of thinking, the pilot jet slows the whole process down by a few milliseconds.

So in theory (in my head...) the vacuum will stay in the faster curve (higher vacuum) longer, and come out of the slower curve (lower vacuum) later as the dampening of the pilot jet works both ways(?).

I will play with the ignition timing once I have sorted the exhaust and see if I can run a bit more timing anyway. I am currently running curve 4 on the Dyna 2Ki but adjusted to give around 25/26 degrees final advance (the module is turned as far as I can get it go in the anticlockwise direction).

[Tomcatt]

Originally Posted by uk_Chap

I was already running at 7 Hg, and the pilot jet trick made this better, but not perfect.

The vacuum will stay in the faster curve (higher vacuum) longer, and come out of the slower curve (lower vacuum) later as the dampening of the pilot jet works both ways(?).

That makes sense now. I didn't realize you started with your VOES set at 7".

In theory the restrictor (added pilot jet) will slow down response time, in practice I don't think it slows it enough to be noticeable.

If you decide to play with this more please let us know what you learn.

[Jfart]

I believe the majority of my issues have been solved as well. It seems to have been a mixture between the clutch and the VOES. Haven’t been able to put a lot of miles on it since “fixed” but almost a tank of gas.

I believe the slipping issue was mostly the clutch. I believe the VOES the as set too low at 5. I’m still not sure how the two were effecting each other so negatively but after adjusting the two the bike is no longer getting as hot and the slipping/ loss of power has gone so far. I believe it was poor timing for the VOES to ground. It was as if they happened at the same time often.

I’d roll on the throttle, that clutch would start slipping a little, when it slipped I’d continue giving it throttle, once the VOES circuit opened the power band kicked in and then the clutch would really slip.

I think I can feel the VOES switch over at times. It’s like it stutters for a second when it does switch. It’s not bad now that it switches at a vac of 7. When it was at a vac of 5 I swear it was switching right after the power band kicked in after I’d roll into the throttle. It wouldn’t happen when I’d open the throttle 50%- 100% right away.

I think UK chap is onto something by setting his right under idle, (8 maybe 8.5) for me. My VOES screw was so damn sensitive, I’m wondering if it’s broken? Turning it 1/8 rotation CW it still registered at 5. Turning between 1/8 CW and 1/4 CW it registered at 7, 1/16 of a turn past that and it would be at 9 or 10. If I turned the screw 1/2 a rotation my VOES light wouldn’t kick on at any amount of vacuum under 10.

My main concern now is I have to shelf my Le Para bare bones seat and put on my bulky looking stock doubles sea. I can hardly keep my ass on the seat once the power band pulls in 2nd at 50% throttle. WOT on a hill climb would have me looking like super man.

Anyone ever modify the back of their stock seat to look like a a fast back? I can think of better places to spend $400 than on mustang fastback seat.