I have a 89 gs500e with supertrapp muffler, k&n drop in filter. I have tried rejetting it my self, helped alot but didn't seem to solve all of my issue's, i have 40/135 2 washers and 3 out. idles fine, anything under 3000 bogs like hell unless i crack the throttle, after cruising at 80 mph for more then 5 miles bike seems to run out of gas and sputters till i come to a stop, prime it then it restarts. o yea im getting 125 miles a tank or so not sure why. for the most part seems to run like hell... any help would be great. thx
You have a couple different questions here that need to be diagnosed.
"idles fine" --> implies that idle set screw is properly adjusted. OK
"under 3000 bogs" --> Implies poor selection of pilot jet and/or setting of slow speed air jet. I think your choice of a #40 pilot jet is OK. How about tinkering with the "3 turns out" to see if further adjustment will help your part-throttle sluggishness. Main jets don't really come into play until the throttle is fairly wide open, at which time your post implies you don't really have a problem. Also, don't forget that this engine really doesn't have much poop down low in the 3000rpm neighborhood. The action happens above six grand.
"Above 80mpg ... seems to run out of gas" --> Ah yes, this is pretty much a standard feature on our GS'es. The vacuum petcock just doesn't flow enough fuel to feed the carbs for sustained running above about 75mph. Search this forum and you will find many posts about this. The only sure-fire fix is to replace the frame petcock with something else, something generic. Or if you want, you can simply turn your petcock to "PRI" although sometimes even this doesn't flow enough fuel to permit high-speed running.
Quote from: 5thAve on May 11, 2011, 07:02:37 PM
"Above 80mph ... seems to run out of gas" -->
Fixed it...
I have this same spot on my commute home where I'm going about 80/90 and uphill, always stutters! I think a petcock update is on the list for this summer.
Funny thing is it seems to get worse when it is windy out? :dunno_black:
Anywho, a clogged pilot will give the symptoms yer describing. I'd pull the carbs and check it.
There was a write up on how to eliminate the vacuum operation and get better flow from the petcock.I agree with what is above.
I just checked and the old thread that shows how to mod the petcock is gone.I guess I'll have to do one this weekend.
135 mains seem a little small for the aftermarket exhaust.
running out of gas is definitely a petcock problem. i went with a later model version, but beware that it is larger. i had room for it because i have a k&n lunchbox filter.
Quote from: reload on May 12, 2011, 06:59:08 AM
135 mains seem a little small for the aftermarket exhaust.
running out of gas is definitely a petcock problem. i went with a later model version, but beware that it is larger. i had room for it because i have a k&n lunchbox filter.
He doesn't have a lunch box air filter.He has a drop in upgraded replacement air filter.I have a lunch box,and D&D exhaust off the right side of a Hayabusa,and I run 40/142.5 jets with no issues.
K&N drop in and pipe = 127.5 mains.
135 is huge. So that explains ... nothing, in fact it says you shouldn't be lean or feel like you're running out of gas, maybe you have a fuel flow issue, once you get past that you will see its richness issue.
Make sure you got flow ... And prime is when it starts - that is a indication you have a vacuum leak, not letting the petcock flow.
Cool.
Buddha.
well when its wide open it sputters rather bad then when i let off a bit on the throttle its and starts climbing again this only happens at high speeds any other time its off the the races wide open.
the 3000 problem, i have to have the rpms over that to get going otherwise its REALLY slow to get up to 10 mph once at 10 its fine.
The mains stocked at 127.5...
i have checked for a vacuum leak cant find one so yea..
someone please help me with this, im at a stand still..
start tearing everything apart. your going to find something dirty/missing/damaged.
pick up a manual and start running through the maintenance items.
The stock mains in a US spec 89 was 122.5 not 127.5.
Something is blocked and your mains are too big, and likely your floats are high ... cos they wear high ... so my guess they are high.
Cool.
Buddha.
i'll check it out and let u guys know. thanks again