Loss of power at full throttle

[The Buddha]

OK this is usually a sign that the slide is rising too fast.
You can improve it with closing 1 hole in the bottom of the slide, but sometimes that doesn't entirely fix it.
You can open throttle slowly and sometimes it helps.

I suspect it only affects some bikes - and why - I don't know.

My old friend who taught me a lot had a GS that used to do this bad. That after he jetted my first bike and rode it and it never did this.
I wanted to try sending him my carbs and testing etc etc, but we never got around it to that cos he sold it before I did.

So anyway - one of these 2-3 options could be tried. In the interest of science.

Send your carbs to me (I am running a 95 with stock airbox with paper filter and pipe) and I'll run it on mine. If it acts up, we know its the carbs.
I'll finagle it and see what it seems related to.

Or find a known good carb set, and run it on your bike. If it mis behaves, its the bike, if not, its the carbs.

Just logically trouble shoot it to smaller and smaller components.

Cool.
Buddha.

[Elmojo]

Thanks for the timing/valve clearance idea bvsilveira, I need to check that anyway.
I'll put that on the 'to do' list.

Buddha, thanks for the offer. I may take out up on that at some point, if the other tests don't help.

[voorken]

I am experiencing a similar issue where in 2nd and 3rd at full throttle I bog down really bad at 7,500-8,000 rpm ... Tired carbs, air filter, spark plugs, sea foam... Guess I'll have to see about checking the timing... If you don't mind me asking how much did that set you back??

[Jordonwiebe]

FOUND MY PROBLEM!!

Apparently this a common issue - its the petcock restricting flow. Apparently the vacuum diaphragm acts up sometimes, putting the petcock to 'Prime' position is a good way to test this. 'Prime' will allow full flow of fuel regardless of vacuum, riding with it in prime position my issues went away.

Guess i'll be cleaning or replacing that petcock

[Elmojo]

Glad you found your issue!
I need to check again, but I think I tried the "petcock on prime" test and that didn't fix mine...

[The Buddha]

It makes sense, cos vacuum is highest @ idle and just off idle, and decreases as you climb the revs. Fuel needs follows the opposite pattern.
Cool.
Buddha.