VERY Slow return to idle - TM36 problem
#1
06-14-2012 | 02:13 PM
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Joined: May 2006
Posts: 881
From: White Rock, BC
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VERY Slow return to idle - TM36 problem
Hi guys, I'm hoping you can give me some advice. I've been trying to jet my TM36-68 pumper carb for best performance.
Even after making large changes (from 12.5 to 22.5 pilot) I'm still having this issue where the throttle revs up, but returns to idle verrry slowly.
I've checked for binding in the cable, but I don't think that's it. With engine off, I can hear the slide clank back down when I release the throttle - it seems to return quickly back to closed position.
I have the Kustom Kraft 330 and a muzzy exhaust. I'm starting with the same settings as Tiger. P6 needle jet, 9EBY01-50 needle, 127.5 main, 22.5 pilot.
Seems like quite a large pilot, but I was getting similar behavior with the 12.5. (though not as bad as the current setup).
Last night I changed out the needle jet, needle, main and pilot from stock to the ones above. The idle RPM became a lot higher in general (around 3-4000 rpm). Maybe that's par for the course given the changes I made.
I tried to dial back the idle adjust screw - it wasn't making a lot of difference. I couldn't get it down to a reasonable idle.
Just wondering if I continue to play with jet sizes and pilot screw depth, or do I start looking for another problem (air leak or something)? It was never like this last year. I took the carb apart for a major cleaning this spring. Pretty sure I got everything back where it belongs.
Even after making large changes (from 12.5 to 22.5 pilot) I'm still having this issue where the throttle revs up, but returns to idle verrry slowly.
I've checked for binding in the cable, but I don't think that's it. With engine off, I can hear the slide clank back down when I release the throttle - it seems to return quickly back to closed position.
I have the Kustom Kraft 330 and a muzzy exhaust. I'm starting with the same settings as Tiger. P6 needle jet, 9EBY01-50 needle, 127.5 main, 22.5 pilot.
Seems like quite a large pilot, but I was getting similar behavior with the 12.5. (though not as bad as the current setup).
Last night I changed out the needle jet, needle, main and pilot from stock to the ones above. The idle RPM became a lot higher in general (around 3-4000 rpm). Maybe that's par for the course given the changes I made.
I tried to dial back the idle adjust screw - it wasn't making a lot of difference. I couldn't get it down to a reasonable idle.
Just wondering if I continue to play with jet sizes and pilot screw depth, or do I start looking for another problem (air leak or something)? It was never like this last year. I took the carb apart for a major cleaning this spring. Pretty sure I got everything back where it belongs.
#3
06-14-2012 | 07:27 PM
Senior Member
1st Gear Member
Joined: Jun 2011
Posts: 1,135
From: San Francisco, CA
why not just email dynojet...give them all your mods and details...and, they'll tell what to use from their dynojet jet kit...than you can use what is equivalent in the jets and such you have...
Hi guys, I'm hoping you can give me some advice. I've been trying to jet my TM36-68 pumper carb for best performance.
Even after making large changes (from 12.5 to 22.5 pilot) I'm still having this issue where the throttle revs up, but returns to idle verrry slowly.
I've checked for binding in the cable, but I don't think that's it. With engine off, I can hear the slide clank back down when I release the throttle - it seems to return quickly back to closed position.
I have the Kustom Kraft 330 and a muzzy exhaust. I'm starting with the same settings as Tiger. P6 needle jet, 9EBY01-50 needle, 127.5 main, 22.5 pilot.
Seems like quite a large pilot, but I was getting similar behavior with the 12.5. (though not as bad as the current setup).
Last night I changed out the needle jet, needle, main and pilot from stock to the ones above. The idle RPM became a lot higher in general (around 3-4000 rpm). Maybe that's par for the course given the changes I made.
I tried to dial back the idle adjust screw - it wasn't making a lot of difference. I couldn't get it down to a reasonable idle.
Just wondering if I continue to play with jet sizes and pilot screw depth, or do I start looking for another problem (air leak or something)? It was never like this last year. I took the carb apart for a major cleaning this spring. Pretty sure I got everything back where it belongs.
Even after making large changes (from 12.5 to 22.5 pilot) I'm still having this issue where the throttle revs up, but returns to idle verrry slowly.
I've checked for binding in the cable, but I don't think that's it. With engine off, I can hear the slide clank back down when I release the throttle - it seems to return quickly back to closed position.
I have the Kustom Kraft 330 and a muzzy exhaust. I'm starting with the same settings as Tiger. P6 needle jet, 9EBY01-50 needle, 127.5 main, 22.5 pilot.
Seems like quite a large pilot, but I was getting similar behavior with the 12.5. (though not as bad as the current setup).
Last night I changed out the needle jet, needle, main and pilot from stock to the ones above. The idle RPM became a lot higher in general (around 3-4000 rpm). Maybe that's par for the course given the changes I made.
I tried to dial back the idle adjust screw - it wasn't making a lot of difference. I couldn't get it down to a reasonable idle.
Just wondering if I continue to play with jet sizes and pilot screw depth, or do I start looking for another problem (air leak or something)? It was never like this last year. I took the carb apart for a major cleaning this spring. Pretty sure I got everything back where it belongs.
#4
06-14-2012 | 08:25 PM
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Senior Member
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Joined: May 2006
Posts: 881
From: White Rock, BC
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Mine is an aftermarket Mikuni pumper carb, similar to what Tiger and a few other members have used... The DJ kit is for our stock carbs, and jet sizes don't really translate directly from carb to carb. (Different chamber designs, type of throttle slide - direct or vacuum driven, etc...)
I think I'm close, the bike definitely has nice power now, but it's dangerous when the RPM's are staying high when I release the throttle.
I think I'm close, the bike definitely has nice power now, but it's dangerous when the RPM's are staying high when I release the throttle.
#5
06-14-2012 | 10:14 PM
Senior Member
Joined: Feb 2009
Posts: 667
From: Hayward, CA
1st Gear Member
When you have it idling, does changing the pilot screw position have much affect on the RPM?
Ride on
Brewster
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