imthatguy
13th November 2018, 11:24
Hi guys,
(thankfully) long time no talk.
I have a few old bikes kicking round in the garage Ive been trying to get working again or summer, one of those is a gsxr250 '89 which is frankly turning out to be a bit of a pain in the ass.
I ended up buying a reposer engine/carbs kit for it as the original one was giving me grief, but I still cant get it working correctly.
Typical symptoms are;
- the faster you go the slower the bike wants to rev
- if you do a full gear pull, the second you change into second (or any subsequent gear) you feel a huge drop in power and it seems unwilling to rev
- generally just surges and runs like shit
It does idle fine, starts up with no extra persuasion and will rev (relatively) cleanly when not under load (although even that sounds a bit strained tbh).
What Ive tried;
- swapping the carbs for my original pair
- cleaning and blasting the carbs and jets
- swapping all the best parts of the two sets of carbs
- checking rubber diaphragms for cracks (none that I could see)
- changing the little rubber o-rings for the mixture screws
- visually balancing the carbs (don't have a balance kit but understand this shouldn't cause issues as described above anyway)
- adjusting mixture screw in all directions
- checking all vacuum hoses
- running with the tank lid open
- running with / without a filter
- running through a tank with injector (fuel system) cleaner
- changing plugs (including a grade hotter / colder then needed)
- recutting leads
- checking spark on all cylinders
- feeling exhaust headers to see if they heat up evenly (they do so far as my handometer can tell)
- trying a new battery
- new fuel (been though a few tanks)
Im feeling like maybe this is related to coils as I hear these bikes are notorious for electrical gremlins, can anyone comment on this?
Would spark breaking down cause issues as described above? Specially what feels like a huge drop in power if I change up a gear / the faster I go..
(thankfully) long time no talk.
I have a few old bikes kicking round in the garage Ive been trying to get working again or summer, one of those is a gsxr250 '89 which is frankly turning out to be a bit of a pain in the ass.
I ended up buying a reposer engine/carbs kit for it as the original one was giving me grief, but I still cant get it working correctly.
Typical symptoms are;
- the faster you go the slower the bike wants to rev
- if you do a full gear pull, the second you change into second (or any subsequent gear) you feel a huge drop in power and it seems unwilling to rev
- generally just surges and runs like shit
It does idle fine, starts up with no extra persuasion and will rev (relatively) cleanly when not under load (although even that sounds a bit strained tbh).
What Ive tried;
- swapping the carbs for my original pair
- cleaning and blasting the carbs and jets
- swapping all the best parts of the two sets of carbs
- checking rubber diaphragms for cracks (none that I could see)
- changing the little rubber o-rings for the mixture screws
- visually balancing the carbs (don't have a balance kit but understand this shouldn't cause issues as described above anyway)
- adjusting mixture screw in all directions
- checking all vacuum hoses
- running with the tank lid open
- running with / without a filter
- running through a tank with injector (fuel system) cleaner
- changing plugs (including a grade hotter / colder then needed)
- recutting leads
- checking spark on all cylinders
- feeling exhaust headers to see if they heat up evenly (they do so far as my handometer can tell)
- trying a new battery
- new fuel (been though a few tanks)
Im feeling like maybe this is related to coils as I hear these bikes are notorious for electrical gremlins, can anyone comment on this?
Would spark breaking down cause issues as described above? Specially what feels like a huge drop in power if I change up a gear / the faster I go..