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Discussion Starter #1
Over the weekend I removed the carb and took it down to basics to see what was going on with the slow return to idle and some other idiot things it was doing. It was obvious that lots of folks had poked around in there as the screw heads were abysmal and much of the jets assembly was jiggered with..Then I checked cables, slide, all the moving parts and could not identify the culprit. I even ran it through the HF ultrasonic tank several times to make sure it was clean. (Used the coffee basket from the Starbucks coffee pot for the jets & small parts). Wifely doesn't know about that yet...

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Then, late in the evening I was looking at the carb diagram and said I don't remember seeing one of those little springs!

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In fact, I did not find the tiny little spring that is #8 in the diagram that resides above the needle collar and keeper on the needle (and maybe closes the main jet when the throttle is not open?).
Where to find one? On line of course but backordered and etc. Local dealer, closed on Monday, had one today, 75 mile round trip for $1.99 part.

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Now the question for the carb gurus out there. IS THIS THE CAUSE OF THE SLOW RETURN TO IDLE?
It can't be that simple can it? Please let it be so!

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No experience with this specifically but your diagnosis sounds very correct. Gonna take it to local Ace Hardware to get a few 35 cent clones before installing and/or letting oem spring go "Boing!"across the shop floor never to be seen again?
 

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Discussion Starter #3
No experience with this specifically but your diagnosis sounds very correct. Gonna take it to local Ace Hardware to get a few 35 cent clones before installing and/or letting oem spring go "Boing!"across the shop floor never to be seen again?
thanks Fred, that's encouraging. I am still waiting for the rebuild kit to show up so I have some time to ponder.
 

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Wish you all the best of luck that that is your problem. But...............my experience and just about EVERY experience Ive read about with slow return to idle the ONLY thing that has fixed it was a new carb.
 

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Discussion Starter #7 (Edited)
Your point is well made. I have ordered a rebuild kit with new brass parts. Any ideas on what other potential causes of slow return to idle may be?
 

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Your point is well made. I have ordered a rebuild kit with new brass parts. Any ideas on what other potential causes of slow return to idle may be?
From all the research Ive done its caused by an air leak...................somewhere. In order for your engine to rev it needs more air than it had not reving. I had the airbox boot off mine and looked down the carb throat with a mirror. When it would go from a higher rpm, then eventually settle down to idle there was absolutely NO movement of the slide, which means it was getting its air from somewhere else. I was never able to figure out where that somewhere else was. This happened to me on 2 different bikes, the TW and a Suzuki GN125. I had the carbs taken apart on those 2 so many times looking for the reason............never could find it. The fix for both was a new carb.
 

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Have and had the same issue... Maybe an exception to what is actually happening with your carb... The exception is that my engine would drop to Idle pretty good until the engine got fully warmed up. Then the throttle would hang. I did the remove, clean, replace the parts that came in the kit.... I replaced the intake manifold and "O" ring... ETC! There are no air leaks.
After I was done the idle issue was better but not really gone.
I experimented a bit and found that if the idle is high and I am stopped if I let the clutch out just enough to drop the rpm off high idle then the engine would IDLE properly....

So I adjusted the idle down to a 900=-1000rpm after the engine got fully warm and the high Idle went away..... Although sometimes as I come to a stop the idle will be a bit high 1300-1400 but it will drop to idle after a second or two.

When the engine is cold and the choke is out I have to hold the throttle up a bit for about a minute... No big deal for me.

I have lived with this for about a year and I am happy with the performance of my DUB. I ride it 2-3 times a week.

I could replace the carb but I currently see no reason to.

I did add an extension and little knob to the Idle jet adjustment... After I got the engine idling nice, on the rich side I have not touched that adjustment in about a year.

I will add that I asked folks here on the forum if someone would intentionally setting their idle high 2000-2500 rpm... Drive it til it got hot and see if the Idle would hang for a second or more.... ... I was curious if setting the Idle high intentionally would cause a sluggish return to the 2000-2500 idle.


Here is a link to that thread:

http://tw200forum.com/forum/technical-help/14298-another-hanging-idle-issue-2.html

Jim
 

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Discussion Starter #10
Thanks Jim, I continue to be encouraged by what I hear on this subject though the real test will be when I get the new repair kit in it. Really glad yours worked out. I have tried the release the clutch and the idle slows at most stop signs but up and down single track, this high idle thing can be uncomfortable to say the least.
 

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Thanks Jim, I continue to be encouraged by what I hear on this subject though the real test will be when I get the new repair kit in it. Really glad yours worked out. I have tried the release the clutch and the idle slows at most stop signs but up and down single track, this high idle thing can be uncomfortable to say the least.
Until you resolve it why don't you turn you idle speed down to around 900... You may find that the high Idle issue will disappear. My TW will idle reliably at 700rpm... I would at least try it just to know that it will work...

Jim
 

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Yup, tried that on my TW. Sprayed a good amount of carb cleaner right at the return spring on the throttle...........just about killed the engine. Yay! finally found the air leak. The seal around the throttle shaft didnt look that great but could not find a replacement. So, I put a thin coat of grease on the shaft and packed the seal area (with the old seal) with RTV. The grease was to hopefully prevent the RTV from sticking to the shaft. Let it sit overnight and reinstall. NO MORE LEAK! But did not fix the racing/slow return to idle problem. :( The only thing I can figure is there is a small hairline crack in the carb body somewhere. It is in the carb though, I took the carb off my 09 to swap over...........fixed. Thats why I just bought a new carb.

I spent hours and hours researching a cure for this on ANY carb, not just the TW. Out of the dozens and dozens of cases I found where they had the same problem I only found one that fixed it. He had a rotten intake boot. I had the same problem on my GFs Suzuki GN125, could never fix it either, solution with it was a new carb. This problem is why I do not like CV carbs. 66% of the bikes I have owned with this carb were bad in the same way (2 out of 3).

So I hope the OP finds his problem, it would be nice to see someone actually fix this problem.
 

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Discussion Starter #13
Bike idles smoothly, accelerates great and no slow return to idle. Fixed? Maybe so...

You might be on the right track but from this photo there looks to me if there is wear on the needle. If so, it will never run right until you replace it and the needle jet/emulsion tube as a set.
I installed the carb I rebuilt yesterday and let it run in the garage for a while. No indication of slow return to idle at all. I replaced every jet, rubber part, spring, and gasket in it and needle as well. I rode it tonight to test the 6,000 lumen beacon I installed earlier (great success on that) and found the bike ran smooth and pulled hard (as hard as 15 ponies can pull). I cannot say that the tiny little spring I think was missing was the only change I made because in addition to new parts and gasket, I ran it through the ultrasonic several times to clear the passages too. Until I run it for a hundred miles or so, I cannot claim I really cured the high idle or slow return to idle but it sure is not having any problems tonight. I also threw a filter in the mix to give it a better chance to stay clean.

Hope this encourages others to tackle this issue.
 

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Sweet, that make about 2 people Ive EVER heard of fixing that problem :)
 
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