am getting a little detonation on an '82 1100GK

[LarryJ]

went my engine is fully warmed, I am getting a little detonation in the 2-5k rpm range under load. I have tried 89 & 92 octanes, & it persists.
What the procedure for setting the timing on these engines?
I am also wondering about colder plugs for the center cylinders.

[Guest]

Richen the needle circuit by removing the spacer over the jet needle and replacing it with washers from Radio shack. Stack the washers the same heigth as the spacer and remove two. If that is too rich replace one but the two should get rid of the detonation with great throttle response.
Have you checked for air leaks? O-rings behind the intake boots? Sealed air-box?

[LarryJ]

thx! will give it a shot!

[LarryJ]

had replaced the o-rings & sealed the airbox when I cleaned up the carbs.

[Guest]

Stock ignition?

[SqDancerLynn1]

I had trouble with my 850 always pinging I had a leaking intake boot After I replaced them NO pinging

[LarryJ]

yes, stock ignition. The intake boots could be the cause too. I do have one cylinder that I cannot get the idle mixture right on.

[LarryJ]

ordered a set of intake boots & o-rings from Z1. Should be here next week.

[tkent02]

yes, stock ignition. The intake boots could be the cause too. I do have one cylinder that I cannot get the idle mixture right on.

Which cylinder?

#2?

[LarryJ]

it sounds like one of the middle ones. the one that I cannot set idle mixture on is the middle one that is closest to the stator, not toward the clutch end.

[LarryJ]

I think that the #2&3 boots probably run the hotest. so, they might go 1st. idk? am replacing them all.

[tkent02]

Not sure what's up, but #2 is the one affected by a bad petcock, fuel leaks into it. Maybe the screw can't adjust the idle because there is too much fuel from the petcock. Too rich in that cylinder by itself wouldn't cause detonation, but a super carboned up piston/head could. Anytime #2 is acting funny I would start by checking the petcock.

[LarryJ]

Replaced the intake boots & o rings. Resynched the carbs. Tried the wayer spray to clean out any combustion carbon build up. None came out. haven't had the bike out since, because of rain. We'll see if it's any better. Been running 92 octane.

[tkent02]

Ride it!! There shouldn't be much detonation in the rain!