Sticky carbs at low rpms

[scribestone]

Greetings,

This is my first post.

I just bought an '81 H model today!
The bike is in great shape but at low rpms it is groggy and wants to die. Once it hits about 3000 rpms, the engine roars to life and off we go!

I am not a mechanic nor do I play one on TV.

Any basic suggestions?

With respect,
Scribe

[psycoreefer]

Most likely a carb problem. Check your idle circuits because 3000 is about the point where you'll be moving from the idle portion of the carbs onto the main jets. Probably dirt in there, or mis-adjusted idle mixture screws.

[bikerphil]

carbs

Carbs probably need a thorough cleaning. Your bike will run like a champ with clean carbs. Temporary fix.. Dump a can of seafoam fuel additive in your tank and run it. This may help, but at the least it will loosen the crap up in the carbs and make cleaning them a bit easier. There is plenty of useful information on this site to do the job yourself. Most shops (I didn't say all shops) don't want to fool with these old bikes. Good luck.

[mro]

Not knowing the history of you bike...

Personally would pull the carbs, disasemble and clean,
check/set float heights, bench synk, then when back on bike vac synk, adjust pilots and then re-vac synk em...

If all else is cool then it should run great. Read thru the tech tips. Very good detail for most problems and the XS is a rather user freindly machine to maintain.

Generally the hardest part is getting the air box off and then back on... Carb job, about 4 hours start to finish. Little longer to be XSpected first time tho.


mro
BTW, have any picks of your ride?

[Axel]

synch first ?

What about a on -bike sync as an easy first sorta thing (and a colortune)
Then maybe you will know how gummed up they are . Seafoam in a strong concentration overnight or as long as possible .I put a full can in at reserve, run it for 5-10 mins and leave to soak (up to a week).



But if you really want to pull your carbs - disregard

[ScottsXS]

if the pilot circuit is really bad seafoam wont touch better off to pull the carbs and clean em........

[scribestone]

Thanks folks! According to the previous owner (short term) he had the carbs cleaned but then discovered the low rpm issue afterwards. It may have sat awhile after the cleaning. He had dumped some Seafoam in it and suggested I do the same. he thought it was the idle circuit too.

Thanks for the info and the tech tip pointing. I'll try to remember to consult the DIY articles before posting a new thread.

With respect,
Scribe

[psycoreefer]

If the carbs were cleaned and it didn't fix the low speed problem you might try adjusting the idle mixture. Its possible that whoever cleaned the carbs didn't take the time to adjust it right. The idle mixture screws are on top down inside a upright tube on the engine side of the carbs. They may have a cap over them so you can't adjust them, if they do then you really need to remove the carbs, remove that cap, and the screws underneath and clean everything. Read the tech tips for some pointers. If they don't then I'd try adjusting the screws before doing the whole cleaning.