gsx 1100 e 1980 wont rev above 5,000

[slideplayer]

Hi peeps, haven't used high revs for some time, now find she can't go above 5k. Everything stock and correct, and found slides are free to raise with fingers and return normally, and raise easily with compressed air off the bike, but i assume aren't lifting properly when riding the bike. Everything else checked and is correct, anyone else had the same problem ? Any advice most welcome, many thanks.

[Nessism]

Please check the newbie mistakes thread linked in my signature to see if anything applies.

[Big T]

Stock air box, or air pods?

[Rob S.]

Hi peeps, haven't used high revs for some time, now find she can't go above 5k.

To paraphrase the 1982 Cycle World review of the new model, you can get into all sorts of legal trouble without leaving the bottom half of the tach. But...

Redline...they like it, they need it. Listen to the advice above and below me. Just curious: how many months, or miles did you ride under 5k?

[slideplayer]

Hi peeps, it seems to rev ok on the stand, but when riding won't rev out. Anyone had the same problem ? Any helpful info most welcome, many thanks.

[John Park]

An '80 should have a mechanical ignition advance which opens fully @ about 4k. If it doesn't, it will rev up when free but not under load. The rotor has a habit of rusting to the shaft from condensation, and some freeing and lubing may be in order. At least with no points you can be more liberal with lubing schemes.

This may not be the problem, but if it is, it's a lot easier to fix than a carb problem.

[slideplayer]

Hi there, ignition advance is working well when checked with a strobe, so perhaps the problem is elsewhere. Could it be starving of fuel at higher revs, carbs have been cleaned and checked several times, and are as specs, maybe I missed something, induction rubbers are new. Any ideas folks ?

[Tom R]

A wiser man than myself once told me that 90% of all carb problems are ignition related; and 90% of all ignition problems are actually carb related.... and this has been scientifically proven.

float levels correct? You can heck the fuel level in the bowls with the carbs mounted.

[slideplayer]

All rubbers replaced and look to be sealing ok, carbs cleaned several times float valves and seats replaced, float height checked, could faulty diaphragms be the problem ? look ok, slides move correctly when lifted by hand off the bike. Why should she rev out on the stand, but not under load when driving ? It's driving me nuts. Can anyone help ? Many thanks.

[Buffalo Bill]

Valve clearances checked?

[Gorminrider]

could faulty diaphragms be the problem ?

unlikely all of them at once

I'm still at fuel supply Turn tap to Prime...after checking that it does indee supply full flow....I think a hearty blip in neutral can be deceiving. If I turn a fuel tap entirely off, an engine will often run smoothly- even "better" until the fuel level drops quite low. However true power decreases.

if this fixes it, apart from the vacuum tap,so also Check the vacuum hose....these can kink closed or part collapse if they are not properly strong (I fixed this booboo today...a suitable looking piece of pipe only kinked when WARM!...) and is something that would affect all carbs together if that is what you are describing...

[salty_monk]

On my 1000G with similar symptoms it was the ignitor that had gone bad... found by doing the AA battery test in the clymer manual

[slideplayer]

Hi peeps, the bike has Dyna pickup coils on it, would a faulty unit cause it not to rev out ? It's charging fine with a good battery, original coils on it and wiring checked seems ok, is there a test I can do to check the sparks at high revs ? She runs fine below 5000. Petrol supply checked looks ok, the same on prime or on position on fuel tap, riding on the road. Any help most welcome. Many thanks.

[Gorminrider]

Um, well, a few Dum Ones but not sure if you have the same exact tachometer as my 650...but they can get weak, or jammed. I've seen this before...where it won't go past 5-6k. Mind you, it's pretty obvious when the bike goes faster but the tach does not. Still, how fast are you going at 5krpm?

Also, from a manual for another bike entirely, among other things, they suggest the front brake is stuck. I know, I know...but that'd do it.