So today I decided to experiment with the carbs on the old gs. Shes been running fine, but has a bit of a flat spot between 4-5k and very poor throttle response when whacked open. Last I checked, the plugs were burning a nice average color of brownish white, right where they need to be.
Problem is, when I want to grab some power, especially in mid range rpm, unless i roll on with medium gusto, the carbs really suck air, and it feels sluggish.
I have a lunch box and a slip on with open baffles, and a dynojet stage 3.2 kit in there.
To remedy, i moved the needle clip around, at 3 from the top, my midrange response was perked up nicely, but it raped my idle something bad, and off idle accel was all but dead. So I know I wont be curing this problem with needle movement.
My question is, should I consult Buddah and go back to mikuni jets and mikuni needles? A new set of slides wont set me back much.
or am I just at the power ceiling for normal street riding, and by opening the throttle up so quickly, I am asking too much? It can only pick it up so quickly maybe?
This comes on the back of finding a couple listings for my favorite bike, the CX500, and maybe having a bit of a motorcycle existential crisis...
also - Can I just stick a newer model, say 2001 seat on my 98, or do they not fit? I like the shape of the newer ones.
What setting was the needle at before? Generally, the needle has only a small effect on idle. You'll be looking to adjust the idle jets and the air mixture screws.
Can you keep both - the CX and the GS? I know the CX is generally un-loved but I kind of like them. With a good bit of work they make great looking cafe's.
And I believe you can put the newer tank on but the seat needs to be a newer model as well. They just go hand in hand. Somebody else could give a more definite answer though.
it was at the dynojet recommended setting, 2nd from the top, as i moved it down progressively to 4th from the top the off-idle got stumblier, and the upper mid range response got better.
The needle has a very aggressive taper on it, so it may have been flooding the mix at idle. I'd go for changing the idle jet down a size, but I want to idle on the main jet less...
Without changing the mixture settings at idle everything went back to normal when I put the needles in their old place.
- It seems to be this, when whacked to WOT under load, something is going wrong, either the slide is coming up too fast and killing the vacuum, or the main jet is not supplying enough fuel?
- The carbs make a lot of noise (like its over lean), but it doesn't bog, per say, its just not accelerating very quickly. Anyone make an aftermarket accelerator pump? haha
as for the CXs, I friggen love those things. I think they look awesome, very few bikes come close to that look. And they are supposed to have lots of torque for a middleweight, which appeals to me a great deal. I prefer the non-custom designs 78-81 when they had the square rank and straight bars and seat.
Quote from: Funderb on March 01, 2012, 09:20:11 AM
it was at the dynojet recommended setting, 2nd from the top, as i moved it down progressively to 4th from the top the off-idle got stumblier, and the upper mid range response got better.
The needle has a very aggressive taper on it, so it may have been flooding the mix at idle. I'd go for changing the idle jet down a size, but I want to idle on the main jet less...
Without changing the mixture settings at idle everything went back to normal when I put the needles in their old place.
- It seems to be this, when whacked to WOT under load, something is going wrong, either the slide is coming up too fast and killing the vacuum, or the main jet is not supplying enough fuel?
- The carbs make a lot of noise (like its over lean), but it doesn't bog, per say, its just not accelerating very quickly. Anyone make an aftermarket accelerator pump? haha
as for the CXs, I friggen love those things. I think they look awesome, very few bikes come close to that look. And they are supposed to have lots of torque for a middleweight, which appeals to me a great deal. I prefer the non-custom designs 78-81 when they had the square rank and straight bars and seat.
I had a similar issues when I did my jetting. The Buddha told me this:
Quote from: The Buddha5.5 to 7 - lift the needle. 3/4 throttle and up is mains, 1/2 to 3/4 is needle. ~ The Buddha
I have an 07 + Yoshi exhaust + Lunch Box and it was giving me hell. Tweaked the needle after determining it was my 1/2 to 3/4 issue using the throttle. Runs great at normal throttle engagement and WOT.
Hope this helps.
OK jetting is related to throttle position, not rpm really ... but yea 1/2 to 3/4 throttle is needle, 3/4 and up is mains.
Cool.
Buddha.
Thanks!
I might be a little on the lean side with the dynojet kit, still, at WOT it sucks air pretty hard. not bogging, but not right
I've helped the problem by plugging up one of the dynojet slide restrictors, and adding weight to the slides.
Would you know that .177 lead pellets cinch down in there nice and tight? haha, beercan tuning all the way.
finally got advice from the honorable buddha. life is good.
Quote from: Funderb on March 09, 2012, 03:19:45 PM
Thanks!
I might be a little on the lean side with the dynojet kit, still, at WOT it sucks air pretty hard. not bogging, but not right
I've helped the problem by plugging up one of the dynojet slide restrictors, and adding weight to the slides.
Would you know that .177 lead pellets cinch down in there nice and tight? haha, beercan tuning all the way.
finally got advice from the honorable buddha. life is good.
What was the helping advice?
QuoteOK jetting is related to throttle position, not rpm really ... but yea 1/2 to 3/4 throttle is needle, 3/4 and up is mains.
Cool.
Buddha
Just that, which I knew, but i feel like its a rite of passage here on gstwins...