Synced the Carbs now it doesn't run.

[tiny84]

Title Says it all Yesterday I got home and replaced the plugs on the bike then synced the carbs. Vacume on each carb is just about the same. the problem came in after i shut the bike down... about 20 min later it was hard to start and this morning it wouldn't stay running. any ideas on what I should be looking at next? it was running realy rich before I did the sync so not sure what I should be doing.

[Chris VB]

I too just had carbs synced and now MPG has droped to 39? What's up with that??

[bobcat]

Title Says it all Yesterday I got home and replaced the plugs on the bike then synced the carbs. Vacume on each carb is just about the same. the problem came in after i shut the bike down... about 20 min later it was hard to start and this morning it wouldn't stay running. any ideas on what I should be looking at next? it was running realy rich before I did the sync so not sure what I should be doing.

 

Did you make sure you put the rubber caps back on the ports? If its running rich could be the choke or a dirty air filter....

 

 

[tiny84]

Yup recapped all the ports... Sorry neglected to mention I replaced the air filter with a new K&N filter 2 weeks ago. Good question though....

 

 

I'm just realy pulling my hair out on this one... this bike has never produced good mileage. if I can't get this running right i'm gonna have to look into tradeing it in.

[GeorgeS]

Did you make sure that the " Throttle Pull Cable " had, At least 1/8 inch of Slack before you started Adjusting the " Sync " Screws. ?

 

--- This is Necessary, so insure that the Left Forward Carb, Throttle Plate is at

the Full Closed Position.

 

Did you then Lower the Idle speed to about 800 RPM, Before begining the Sync

Proceedure? Useing the " ONE" Main Idle Adjust Screw, ( Plastic Knurled Knob ) on the Left Forward Carb ???

 

Did you take Note that as you Brought Each Carb, Into Sync, with the Left Fwd

Carb, that you achieved Some amount of Idle Speed Increase ?

 

When you are finished, you Must have " Some " amount of Slack in the Pull Cable

betwee 1/16 and 1/8 inch of cable movement, before the Plate starts to move.

 

--- Check your Pull Cable, IF there Is --- NO Amount of Slack--- Then you

have to start all over.

 

Study, the Diagram on Page 2-12, Remember, Throttle plate #2 is the Master.

 

It must go to Full Closed, when you Close the Throttle .

[tiny84]

ok now most of that was information I didn't know.

 

I did know about the idle speed set at 800-900 rpms. I was at around 1100-1200 when i finished the sync.

 

how should I go about getting back to a base line where the bike actualy runs so I can redo the sync correctly?

[Gearhead]

That's weird, engines will normally run with really bad sync (not well, but run none the less). You said it was running really rich. Sync won't help that. Have you checked your fuel levels in the carb bowls? That and pilot screw setting is critical and could account for trouble. It could be so rich that it fouled your new plugs already.

 

Chris, my average mileage would have to go UP by about 2 points to get to 39. :-) When I got mine a couple years ago 'twas in need of many things and was getting something like 32. The tuneup stuff, repairing the boost sensor, etc got the mileage up to 37, but...when I synced the carbs, mine actually went down a point or two as well. Can't figure that one out.

 

Jeremy

[Freebird]

Yea, something is very perplexing about this one. I've seen bikes with carbs WAY out of sync but never bad enough that they wouldn't start. I think there is something more to this but I'm not sure what without being there.

[tiny84]

I can say that the bike ran well and pulled ok before the sync. the plugs i pulled out still looked new but replaced all the same. i'm thinking about just dropping in the backup set of carbs I picked up that were said to be 100% working and then sync those and see if maybe there is somthing screwy with the carbs that are on the bike now. I cleaned them last season but didn't seem to make any change.

[Marcarl]

First, look at your kill switch, then put up the kick stand, then use some choke. Now it should start.

[bobcat]

Title Says it all Yesterday I got home and replaced the plugs on the bike then synced the carbs. Vacume on each carb is just about the same. the problem came in after i shut the bike down... about 20 min later it was hard to start and this morning it wouldn't stay running. any ideas on what I should be looking at next? it was running realy rich before I did the sync so not sure what I should be doing.

 

A shot in the dark.....a few years ago a friend of mine had similiar problems as you described....wound up he accidently put diesel fuel in his bike...

[friesman]

You didnt perhaps fill gas just before the synch and get a bunch of bad gas?

 

Just grasping at straws here

 

Brian

[Venturous Randy]

If you have a vacuum leak, you may have compensated for the leak by the sync job. Check all your YICS connections, especially where they connect to the engine. Or, take it off and plug the fittings with good strong caps. Then try the resync again.

RandyA

[capn eddie]

Just a thought did you check the new plugs to see if they might be fouled out since you did the sync. job:detective:

[tiny84]

Ok bike fired up today. GeorgeS gave me some pointers on the pull cable settings... Still didn't fire up. Then I backed out each of the sync screws all the way then tightend them in 3.5 turns. by this time the battery was very low so I stuck it on the charger over night. Bike fired right up today. but unfortunatly this means the bike is way out of sync again.

 

Anyone looking for another first gen with Upgraded speakers and highend CD/DVD player indash?

[MikeM8560]

Is it really necessary to sink the carbs if everything seems ok. mine runs great and im getting 46 mpg?

[Freebird]

I may be wrong but it sure seems that you are mixing up the sync screws with the mixture screws. I have been trying to figure out HOW syncing the carbs was causing it to not start. I think you have syncing mixed up with air/fuel mixture. You don't touch those screws when you sync the carbs.

[tiny84]

It is indeed very possible that I am incorrect but I think I have the right screws. only 3 screws all attached to the throttle pull linkage. If anyone has a pic of the correct screws I'd love to be able to confirm or disprove what i've been looking at.

 

The sync screws are the one located between carb 3 and 4 and one between 1 and 2. I thought fuel enrichment screws were actualy on the carbs.

[tiny84]

Is it really necessary to sink the carbs if everything seems ok. mine runs great and im getting 46 mpg?

 

 

True if nothing was wrong I wouldn't be doing anything to it. but the bike smells like its running very rich and gets terrible MPG. One post I saw somewhere was someone complaining about backfireing and poor mileage "mobile home mileage" and doing a proper carb sync cleared it up... my bike would backfire occasionaly and gets bad mileage...

 

 

I'm a religeous member of the "If it ain't broke don't fix it" Congregation so if it wasn't broke trust me I wouldn't be trying to fix it.

[mbrood]

It sounds like you have it understood.

 

 

The mixture screws are below the diaphragm cover on each carb and the sync screws are as you described, with "balancing" springs on them to hold the preloaded postion of the sync plates.

 

I believe you should be able to pull the airbox cover and filter and look inside... The first step is to see that number 2 is fully closed with the throttle relaxed.. not enough slack in the throttle cables can keep this one open a bit and all the other carbs sync to that one.

 

As you CRACK the throttle, all four butterflies should come off a fully closed position together. If you can see that this isn't the case you have a starting point.

[GeorgeS]

It sounds like you have it understood.

 

 

The mixture screws are below the diaphragm cover on each carb and the sync screws are as you described, with "balancing" springs on them to hold the preloaded postion of the sync plates.

 

I believe you should be able to pull the airbox cover and filter and look inside... The first step is to see that number 2 is fully closed with the throttle relaxed.. not enough slack in the throttle cables can keep this one open a bit and all the other carbs sync to that one.

 

As you CRACK the throttle, all four butterflies should come off a fully closed position together. If you can see that this isn't the case you have a starting point.

 

Right, If #2 throttle plate, is not fully closed before you start, go back, put some slack in the cable, then set the Main Idle Adjust Knob ( Under #2 Carb ) To " Just " makeing contact with the #2 throttle plate.

--- Now if it will run, start the Sync of #1, #4 and #3.

[tiny84]

It sounds like you have it understood.

 

 

The mixture screws are below the diaphragm cover on each carb and the sync screws are as you described, with "balancing" springs on them to hold the preloaded postion of the sync plates.

 

I believe you should be able to pull the airbox cover and filter and look inside... The first step is to see that number 2 is fully closed with the throttle relaxed.. not enough slack in the throttle cables can keep this one open a bit and all the other carbs sync to that one.

 

As you CRACK the throttle, all four butterflies should come off a fully closed position together. If you can see that this isn't the case you have a starting point.

 

 

So for my running rich issue should I be screwing with the mixture screws?

[Freebird]

Yep, sounds like you are doing it correctly. It just confused me a bit when you started talking about backing them all out then 3 1/2 turns in and etc. Hadn't heard of that before when syncing carbs but there it is a standard way of finding a starting point for the fuel mixture. Except it's all the way in and then back them out 3 - 3 1/2 turns.

 

Sorry, didn't mean to confuse things.

[tiny84]

Yep, sounds like you are doing it correctly. It just confused me a bit when you started talking about backing them all out then 3 1/2 turns in and etc. Hadn't heard of that before when syncing carbs but there it is a standard way of finding a starting point for the fuel mixture. Except it's all the way in and then back them out 3 - 3 1/2 turns.

 

Sorry, didn't mean to confuse things.

 

lol yeah it was my own way of finding a common ground where the bike would actualy start. I think it means the #2 valve is staying open slightly and when I sync the carbs to it they all stay slightly open this means the bike wont start. but once i set all the other screws closed then the bike can start with just the #2 carb slightly open. this is my thoughts on what must be happening. when i first was looking into doing the sync I did have the bike running with the air box off and noticed the plunger on carb #2 moved more just ideling than any of the others. this also leads me to think it stays slightly open.

 

and you didn't confuse things all aspects probly need to be coverd on this problem... i'm paying more in gas now then I do for rent...

[mbrood]

I think Freebird took your mistaken count and then used your mistaken turn count. On the 1st gen bikes.. from a "softly seated" idle mixture screw, you want to turn it out 2 1/8th to 2 1/4 revolutions.

 

It's a fuel feed, so further out means richer, in more equals leaner settings.

Edited July 26, 2008 by mbrood