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Xr600r dual carb update?

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I have a 85 xr600r and I'm haveing idle issues (go figure) and I've been thru these carbs around 4 times looking for the problem and I'm about fed up with the carbs.  Are there any other carb that will work on thise bike ? I would like to stay with the dual carbs for the performance aspect of them. 

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If the carbs are clean, especially the pilot jet and circuit, I would look into other issues. Weak stator or coil or valves out of spec? Need to go through all possibilities systematically and the issue will present itself. An easy one is if you have messed with the idle while working on the carbs and left it too low. Start with the simple solutions and move on from there. 

Good luck!

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Ok already has new high output stator and valve has been set to factory specs and timing checked. I have a fealing I'm dealing with a worn carb issue. One question I have is the air buypass valve the tit on the diaphragm it it supose to fit snug in the bore it goes thru? Cause the one in my carb has a lot of play almost like it's the wrong valve for the carb. I would buy a new one but know body sells them for the 85-87 dual carb xr600r's I'm having a hard time finding gaskets and seals for them too. That kind of why I'm was leaning towards replacing them with newer carbs. 

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I've cleaned and tuned this type of carb set up on numerous bikes. I've had (3) XL600r's and an '84 XR500r over the last 10 years. I wouldn't say I'm an expert, but I'll try to help. I'll assume you have good compression and the health of the motor is good so we can focus on the carb's. The diaphragm, from my understanding, is to richen the mixture under deceleration so Im not sure how it would effect idle if not working correctly. Maybe others will respond on that. Is the spring and o-ring in place with the diaphragm? How does it run other than idle? Is this a new problem? Did you disassemble the carbs all the way down to clean? I never needed to separate the carbs but all parts should be removed for cleaning. Also important is the air/fuel screw. Make sure it has a good o-ring and washer. 

 

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Sirius Consolidated Inc  . Try these guys  they are in Ontario Canada but they ship to the states.. I have used there carb parts in my xl 600. I think the air  valve from a newer xr will work but you have to use the original spring 

 

 

 

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Due to the unique way the dual carbs work (right carb doesn't have an idle or choke circuit) it would be harder to dial in with 2 new nonOEM carbs. I was able to get a few parts for mine on eBay (mines an 87) and it ticks like a watch now. I do the high idle when starting and back it off when it's warm like others with older 600s and it seems to work out (also starts first kick every time)

 

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Thanks for all the idea guys. But one thing still makes me wounder is the tit dia on the diaphragm ves the bore i.d that it goes thru. Mine is way smaller than the bore and I'm not sure if it's suposed to be that way or not? If not that might be causing my idle issue. I have a oem manual for the bike and I can't find any clear pic of how it fits in the bore of carb.  As for compression it has plenty that's for sure and it runs good and after figuring out the starting trick to these big thumpers it starts fine. 

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Did you install a new ACV diaphragm or rule that out? If I remember correctly the little nub is ok being smaller as it pushes on the valve to let fuel enter. Somebody correct me if I have that wrong. It still needs to be sealing correctly so if its torn or the oring is gone it could be an issue.

If it starts and runs under load with good power than I would look again at the pilot circuit. Something is clogged. Either the jet itself or the circuit within the primary carb body. Or the fuel screw is not sealing or has an issue. Fully disassemble and spray a quality carb cleaner through all orrifices and jets. The pilot jet and passageways are small and easily clogged up. Only you know how well a job you've done with this. I make sure when I spray a circuit out that I know where it should exit so I know its clean. IE-Spraying into the fuel inlet you know its going to spray out the seat with the needle removed, etc. Be sure to have your safety goggles on . Ive been hit in the eye numerous times with carb cleaner as it splashed back. You just have to dig into it and keep working until you figure it out. You'll be an expert on how these carbs work and have a feeling of accomplishment when you fix it yourself.

Final thought-How many idle screw turns does it take before it will idle? Eventually you'll be idling more via the needle then the pilot. Just an exercise to try.

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Also make sure the slides are closed in down position, so the idle circuit can work.

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I've cleaned all the circuits in the carb with cleaner and have the mixture screw out around 1 3/4 turns. It will idle right some times. The acv diaphragm loose like it's new and I don't see any holes in the diaphragm. I went ahead and ordered a rebuild kit and diaphragm from Sirius Consolidated Inc.  I'm woundering if the acv is the same as mine being know body knows how to tell what the right one looks like.

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Sounds like progress so keep at it. Get it warmed up and try turning the mixture screw out until you get the highest idle. You may need to change your pilot jet. Its all trial and error. The mixture screw/pilot procedure is below. I copied and pasted from another post.

--Warm up the bike to full operationg temp.

--Turn up the idle slightly (a few hundred RPM). This is only to help distinguish small changes in idle speed during the following steps.

--Turn the screw in until the idle starts to drop and/or miss a little. Note that position.

--Now turn the screw out until the idle starts to drop and/or miss a little. Note that position.

--The ideal setting is half way between the two noted postions.

--The goal is to find the setting that provides the smoothest and highest idle speed.

--Readjust the idle back down to the correct speed after the screw has been set.

--Typical settings are between 1 1/2 and 3 turns. If the best setting is more than 3 turns out the pilot jet is too small. If the best setting is less than 1 turn out the pilot jet is too large.

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Well I got the kits today and I don't think it is going to fix anything the acv looks the same as the one in my carb now. 

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I'm thinking of trying that first before I put these kits in cause Im pretty sure these arn't going to fix my problem anyways. 

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What exactly is the problem you are trying to resolve? You said it has intermittent idle issues but can you describe it in a little more detail?

An ACV issue is usually pretty obvious when disassembled and held up to light. If it looks good and is assembled correctly I would move along to other potential causes of the issue.

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It's a intermittent high idle.  When it does it you just have to burp the throttle and it will come down and sometimes idle just fine. That what I'm trying to fix 

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It's a intermittent high idle.  When it does it you just have to burp the throttle and it will come down and sometimes idle just fine. That what I'm trying to fix 

Ah, that's called a hanging idle. It can vary based on operating temp or ambient air temp. It is typically a sign that you are lean on your pilot circuit although there can be other causes. Does it pop and crackle on deceleration?

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