idle adjustment

Hello all!
My name is Andrew and I am new to the site and to the XJ world. I just bought a 1980 XJ650 Maxim. When I purchased it I was informed that there was an idle problem. His complaint was that it would idle too low and die. I assumed that the carbs just needed adjustment/needed to be synced. I have been riding it and found that after riding for around 15-20 minutes, it stops idling low and starts idling around 4000 rpms. I don't know if there is any correlation, but there seems to be a lot of drag on the clutch. I haven't started looking into the clutch as I would like to get this problem resolved first. Some suggestions have included rebuilding the carbs. I don't have a shop to work out of, so any help would be appreciated. I also have not yet changed the plugs/changed the oil. The previous owner was also not particular as to the quality of gasoline that he ran. I bled some gas from the carbs and found some trash/debris.
Any help here would be appreciated.

 

a few other notes. It has a K and N air filter. also, he has several different brands of spark plugs. Again, I have not had a chance to replace them yet. While there is some drag in the clutch, I only have issues shifting when the idle is screwing with me.
Thanks again.

 

You are going to need to:

Service the carbs (properly clean and adjust, including float levels.)
Get the valve clearances in spec.
SYNC the carbs.
Rebuild the brakes.

Simply going to have to, it's a 30-year old bike. Sorry.

 

Fitz, as always, has you on the right path. Debris in the carbs isn't about gas quality, it's about maintenance quality. A previous owner who has carbs in that state makes me curious about the more important parts of the bikes.

Look at your front brakes likes and check the date, if they aren't from 2009 or later, they need to be replaced before you ride again; rubber brake lines are only good for 4-5 years. One panic stop and the lines could rupture. That means a very short riding experience. Stopping is way more important than going.

Here's a good starter post with links: http://xjbikes.com/Forums/viewtopic/t=43470.html
If you decide you don't want to do all that work (absolutely necessary with a 30 year old bike), do yourself a favor and sell it to buy a newer model. If you chose to continue with it, you'll learn the self sufficiency skills (and frustration) that we all pride ourselves on!

 

Thanks for the info. I checked the brake lines. They are original to the bike (april of 1980). Definitely going to get that taken care of. My little brother works at a small engine repair shop. I already have it scheduled to have the carbs rebuilt and synced. I am going to get him to check the valve clearances. I am going to change the engine oil and drive oil. already changed the plugs. Anything else that you would recommend?

 

Yes, click on the link that Kilted posted and read/ follow links within it.

Yes stopping is more important than going but stopping when you don't expect it (rear brake de-lam.) can truly suck.

 

I highly recommend going to Stainless Steel brake lines if you can.

You can check the clearances yourself, it's not hard and requires only one special (and cheap) item...the feeler gauge. If nothing else, see if you can watch when they do it.

Since the lines are original, I'd replaces the compression washers (4 large, 8 small, PM Chacal for a price quote) on the valve cover too, they are undoubtedly original too.

 

Valve gasket would be done for too.

Seriously, like others have stated, go over everything. all those rubber gaskets are 34+ years old...

One other thing mentioned.... Check your tire date codes! Tires probably look good, but I bet they are too old....