Is this the timing?

[CoreyCorey73]

My Eleven Special does not want to idle, and it will only run if you keep giving it gas. It backfires and hesitates a lot. I thought it was the carbs but I had them cleaned and got another opinion, and the man told me that the timing was off. It will only truly run right with the choke out. Could this really be timing or something in the carbs?

Thanks!

[POOLBOY]

Mine too

Hi,I just tagged on to this thread so I get a notice when someone reply's. Mine does the same thing.
I dont understand this "triple cleaning" thing on the carb's.It seem's to me that if you do it correctly the first time, you wouldnt need to risk breaking something like the float post's by doing it two more times.My carb's are COMPLETELY apart, and I am ready for the cleaning/rebuild.


********************SPLASH!*********************** **

[John]

My first guess would be the carbs are plugged up. If it will only run well at full throttle, or with the choke out, that tells me that the idle circuit is stopped up.
1st question: Is this a project bike, or have you been riding it regularly?
2nd Q: If it is a daily driver, did it run out of fuel recently?
3rd Q: How did you clean them? Did you disassemble them, or just spray some carb cleaner in them?
4th Q: How does it run whith the choke on? Smooth? The choke circuit actually opens a passage to the float bowl, that allows the vacuum to draw more fuel into the carbs, behind the slides. It does not restrict the air flow. If it runs ok with the choke, it's probably not the timing. The problem is probably in the idle circuit. Look in the maintenance tips here, and you will find very good step by step procedures for cleaning the carbs.

[John]

Re: Mine too

Originally posted by POOLBOY
Hi,I just tagged on to this thread so I get a notice when someone reply's. Mine does the same thing.
I dont understand this "triple cleaning" thing on the carb's.It seem's to me that if you do it correctly the first time, you wouldnt need to risk breaking something like the float post's by doing it two more times.My carb's are COMPLETELY apart, and I am ready for the cleaning/rebuild.


********************SPLASH!*********************** **

Triple cleaning means; when you think you have them clean, clean them again, and again. before you assemble them. There are many small passages in the carbs that can be stopped up or affected by a small amount of dirt, or old fuel that has varnished. Using compressed air to blow then out helps also. Use a good brand of carb spray. Berrymans brand comes to mind. DO NOT SOAK THEM IN CARB DIP! That will eat up any rubber pieces. Separating them down from the rack is not necessary. If possible, remove the pilot screws, the pilot air jets on the lower front part of the carb, and anything else that can be removed. Remove the tube that he main jet is screwed into, and check all of the small holes in it. They affect mid range throttle.

[pgg]

I'd set the floats, check the needle notches, set the idle jets, check the air pilots, check the main jets, check the pilot jets, check the air jets, check the carb boots, check the air filter, check the gas taps, check the gas cap breather, check the gas hoses, check the high tension leads(in the dark,) check the compression, check for smooth carb slides, sync the carbs and run a timing light! If nothing happens, throw in the towel, junk the bike, buy a moped.

[John]

Originally posted by pgg
I'd set the floats, check the needle notches, set the idle jets, check the air pilots, check the main jets, check the pilot jets, check the air jets, check the carb boots, check the air filter, check the gas taps, check the gas cap breather, check the gas hoses, check the high tension leads(in the dark,) check the compression, check for smooth carb slides, sync the carbs and run a timing light! If nothing happens, throw in the towel, junk the bike, buy a moped.

And, don't forget to take a breath between all that

[CoreyCorey73]

John,
Today I got the bike running and actually drove it and it runs fine going down the road, but when I put it in neutral it revs up to about 4000 rpm and hangs, and it will not go back down unless I shut the bike off and fire it back up. To answer your questions:

I recently bought the bike from a man who let it sit up a year, so it has not been run recently. I had the carbs cleaned and I put new plugs in it. I disassembled the carbs and thoroughly cleaned each part. It runs with the choke on but it still backfires. Anyway, the main problem now is that the throttle keeps hanging. Maybe somebody knows what to do about that.

[TopCatGr58]

Hey there Corey,

Aside from doing a search on here, which you would find tons of info, one thing is, after you disassembled the carbs, then put them back together, did you do at least the bread stick tie synch of the butterflies to try to get all of them fairly close to the same amount of open? Secondly, when you put the carbs back on, you might have gotten the air filter or intake tube clamps rotated to where they are rubbing against the throttle plate/rocker device which would allow you to increase throttle, but then can catch the plate and hold it open, causing the high revs.

But, if you are having to run it on CHOKE, that, too can and will cause it to rev high, as will them not being closely synched! Also, check your throttle cable to ensure that it slides freely, and is not getting hung up, or is stiff or bent somewheres!
T.C.

[John]

Corey, I would do what TC suggested. Another guy here had the same problem of not idling down, and he was adamant that the cable wasn't hanging up. He rechecked and found a problem with the cable routing, AND the clamps on the carb to airbox boots had rotated when he tightened them, and they were interfering with the linkage.
When you disassembled the carbs, did you pay close attention to the small holes in the emulsion tubes? Did you run a fine wire through them? These directly affect the idle and mid range throttle.
You never did mention what year Special you ride. The carbs were modified from the 78-79 application to 80-81's. Also, did you remove the pilot screws? These were sealed in the 80-81's. If you did, did you bottom them out and set them to 1 1/4-1 1/2 turns after reassembly? I'm asking because I recently did some carbs from a 78 E model, and I broke the tips of two of these screws off in the carb body. The tips are very thin, and will break very easily. They are hell to get out, but can be done. If you pull the carbs again, look on the top of the engine side of the throttle body and see if there are no small brass needle tips protuding. If there is, then they must be removed, and new needles bought. They are still available, but a little expensive, $15 a piece. The ones I bought were OEM Yamaha. Look in the maintence section here in the home page in the forum, to find tips on how to remove broken tips.

[CoreyCorey73]

The bike itself is a 79 but from what I remember the guy told me the motor is an 80. It does not have a kickstarter. I had a mechanic I trusted clean the carbs and he said he went all through them, and it ran a lot better after he finished but it is still backfiring and another mechanic told me that it was the timing. But I guess I will just have to take it to a Yamaha shop to truly get it right. Thanks!

[mitch]

Yamaha shop

Alot of those shops dont have a clue what to do to a 25 yr old bike a lot of the members will attest to that. where do u live maybe a member from here can help you. They sure helped me a lot. I HAD A FRIEND SPEND 1000 DOLLARS AT A BIKE SHOP ONLY TO HAVE ME FIX THE TROUBLE FOR ABOUT 50 BUCKS!!! sorry about the caps didnt see that lol.........MITCH

[TheDjost]

Do it yourself and save the $$. You will also know it is done correctly. If it's already been taken apart recently, nothing *should* be stuck. All it takes is a couple of good screwdrivers, a can of carb cleaner spray ans some patience.

-Justin