Idle hangs at 3k-4k

[JadericD]

I've been reading this sight for close to a year now and you guys have helped me take a bike that hasn't ran in ten years and get it back on the road. Just last week, after cleaning and recleaning the carbs, new needle and seats and cleaning up the gas tank, I finally broke down and set each float by the method discused on here of using the clear tube. I got all four as close as I could and presto! It fired up and ive been riding it.

With the air box completely on it was running to rich to ride. It would bog down at around 4-5k so I took off the bottom cover to the box and made my own filter. Basicly I let a whole bunch of air in. She started running like a dream with this set up or like a dream from what it was. Now what happens is when I first fire it up in the morning it doesn't want to idle and as it warms up it idles better and better till a point when it will idle just above 1k then goes a little to high to 1.5-2k. This whole time when I go to change gears (between all) it will idle around 3-5k depending on how hard i accel. and make the gears clank a little because of the extra rpms. My question is how do I fix this problem, the idle and the hanging idle?

This may be my first post, but I want to thank you guys that help. There is no way I could have got it running again without you.

p.s. It is a dream come true to unleash a beast that hasn't ran for so long.

[wingnut]

sink um

Have you synced the carbs yet?

[JadericD]

I did the pre synch that is directed with the bread wire. That really helped. I think all it did was synch the carbs to each other though and not to the vacume the engine is pulling through each one. I've seen people talk about some sort of vacume syncin but I'm not sure how to do that. I've also read that the bread tie will get it close enough for good performace..would this be causing the idle to hang?

[xssiveone]

Yes, it's quite common to have idle problems if the carbs are not sync'd to each other. The bread tie method will get you very close, but there will still be room for improvement. The vacuum sync or it can also be done with mercury tuning sticks, is to balance carb 1 to carb 2, then carb 4 to carb 3 (carb 3 is unadjustable) and then 1-2 to 3-4. This is done by adjusting the screws on the linkage between the respective carbs. Then adjust the air-fuel mixture for each carb, readjust the idle, and then sync again. Remember, it's not important how much vacuum each carb is drawing, but that each is adjusted to be equal. I say this last because there is sometimes some confustion with the gauges. They are auto vacuum gauges, and have a green zone, yellow zone, and a red zone. Ignore the colour bands, and just pay attention to the numbers.

As to which method you use, it's a personal choice. I purchase a gang of 4 vacuum gauges from JC Whitney, only because I didn't want to bother messing with mercury. Others will tell you the merc sticks are more accurate. Don't know, don't care.. the gauges work for me.

You DID ignore the manuals dire warnings about removing the idle mixtre screw I hope? This seems to be a common problem area, if you don't remove the screws, then you can't be sure the passageways underneath are clean, or that the tip of the adjusment screw isn't broken.

[JadericD]

Yes I did take out all four idle adjustment screws and make sure they were intact and clean. I guess, just as I finally broke down and adjusted the float levels the hard way, its time to break down and sync the carbs correctly. The left side is running better and hotter than the right and is also the only side that works during idle. Probably my idle problem. So I guess thats the next step, just do the work right the first time.

Thanks a ton Brian...I'll give what you've said a shot.