Can't clean carbs but what can I do with the floats?

Hey guys.
So I don't have time to clean the carbs completely right now on the bike. The weather is too nice and I just don't have the time to tear them apart right now.

The bike starts fine, runs well with the choke on but when the engine warms up and its time to turn the choke off it dies. It will run with the choke on. It seems that with the petcock on PRI it helps a little bit. I suspect it is the floats because the PO left the petcock set to PRI for a long period of time and flooded the entire thing with gas. It was coming out the airbox even. I have flushed the entire thing with oil and I will again before I run the bike.

What can I do with the floats in a relatively short period of time? Any other suggestions to check for this problem? I don't think its as simple as the idle screw but I haven't tried it yet.

Any suggestions would be great. Thanks again guys

 

Have you tried an internal carb cleaner? like Gumout or Berryman's? As for the floats, it's real hard to take the bowls off with the carbs still on the bike, so if you take them off you may as well do a jet removal and soak'em, 'rod' them out with a bristle from a brush. But with any cleaning job, you get out what you put into it.

 

You can't. There's nothing you can do with the floats without pulling the rack, other than check the levels.

The "choke" isn't a true choke, it's an enrichening circuit; your symptoms indicate that you need to service the carbs.

There's no quick or easy fix; and if you keep getting gas pumping into the crankcase, you're just gonna hurt the motor.

 

You know you'll enjoy the bike much more if it's running right. Take the time and pull, clean and service the carbs properly. You'll be glad you did.

 

Fuggers, (that's a good one LOL ) If you start work at 8:00 am you can be done by 6:00 pm when you do a basic cleaning (if you don't stop for lunch).
Trust us all you'll be glad you did when she fires up and runs right. And it wouldn't hurt or take a little more time to pull the petcock, take it apart and see what's wrong with it; may just be clogged with varnish.

 

You're probably all right, the weather is so nice and I have limited free time. I'm gonna try the simple solution so that I can at least feel the bike moving after the recent transformation.

You can all say I told you so in about a week, when I break down and go through them entirely.

 

And check your valve clearances. Since you won't be able to get a decent vacuum sync if they're not in spec.

 

I just replaced all the shims. Unfortunately I tore a 3 inch section of the valve cover gasket off and the replacement is 40 bucks. Is there any way I can mend this and get away with it? I know it seems cheap but the wife and I are both in graduate school and every dollar counts.

 

That sucks. :cry: You could try some gasket compound, with the torn section in place of course. Mileage may vary.

 

Look up making homeade gaskets, and use the torn one to trace a new one.

If you want to just do the minimum, pull the carbs off and just clean out the jets there and the fuel passage pressed into the bowl. Reassemble, set float levels while they're off, and put back on. Presto, it won't be perfect, but it should help a ton.

It's a temporary answer to a permanent problem, though, but it might be enough to make you happy.

 

Thanks for the tips, we're almost done with the custom led taillight and then its finally time to ride

 

There's a product called gasket sinch or something like that. I have used it for years to hold float bowl gaskets ect. in place while assembling them, it work's great. This way you could hole the valve cover gasket in place while assembling it. Today when I was down at the auto parts store I noticed a new product, don't remember the name but they said that you could use it to glue rubber back together, who knows, might work??? A repair like this is never as good as a new valve cover gasket but it might just work? Grunt007, 81'Xj 750 Seca R. I feel for you because I just had to buy a new $40.00 valve cover gasket. It still smarts to say the least. Michigan

 

So I got the bike all buttoned up and spent all day running around on it. I'm absolutely in love.

However, the bike will die after about 2 miles if it is set to ON or RES. The bike will start right back up and run alright if I turn it to Prime. What are the chances I have a vacuum leak? Perhaps this is a float bowl issue? Maybe I'm running through the gas in floats and then it can't keep up after that. Petcock wouldn't work in PRI if it was plugged correct?

Also the clutch is slipping but I had to flush the engine with regular car oil because gas got in the system. I forgot to take it off PRI and it filled the crankcase. I'm hoping this is why the clutch is slipping, this or I have the leverage arm at the transmission too tight and the clutch isn't engaging all the way.


Did I mention I'm in love with the bike now?

 

You can get a rebuild kit for the petcock for 30 bucks from chacal. It doesn't sound like a vacuum leak, it sounds like on/res just don't work--so you should put your finger over the vacuum port on a manifold carb-to-engine boot and make sure you feel a vacuum on the off chance it's plugged, and then make sure your vacuum hose is good--snug fit, no cracks/tears, etc. If those are good, then it's the petcock itself. (there's also a small chance your hose was replaced with hose that is weak enough to collapse on itself and stop vacuum, but it's pretty unlikely. Eyeball it and see if it looks stiff enough to hold up, it's not a ton of suction.)

And yes, it takes a minute or two to go through the gas in the bowls.

No gas should flow at all in on/res when the bike is off, so the bowls shouldn't be filling up when the bike is off when it's on those positions--it should only run two minutes on those positions if you first set it to prime and filled the bowls.

That is very likely why the clutch is slipping--switch it with motorcycle non-synthetic oil and you should see a huge improvement. Otherwise, clutch friction plate replacement isn't too complex or expensive usually. There's a video of the process in my sig. There's a thread by rickomatic on adjusting the clutch, that's the first step after the oil change--that will probably fix it, unless the bike sat for a long time before you got it. Did the slipping start happening after you changed the oil?

Anyways, better a slipping clutch in car oil and parts wearing with gas-thinned motorcycle oil, I'd think.

(And yes, you mentioned your love I think.

 

In order for this to happen, one or more floats weren't doing their jobs.

When everything is working as it should, you could theoretically leave the petcock on PRI and nothing bad would happen. All leaving it on PRI did was to reveal an issue. You need to address your floats/float levels, or you'll keep getting gas in the crankcase.

Your petcock is behaving the way it is because the "vacuum operated" part isn't working. Petcock tech: http://xjbikes.com/Forums/viewtopic/t=25058.html

Your clutch is slipping because it is 30 years old and was in pretty frail condition before it got gas and car-oil soaked. Adjust the cable properly and see if it "clears up." If it does, it's temporary anyway; the clutch is something that will eventually need to be rebuilt.

Have you visually inspected the rear brake shoes yet? http://xjbikes.com/Forums/viewtopic/t=15874.html

 

Just one thought. If the vacuum pipe from one of the brass inserts to the petrol tap is broken/badly split/missing then
a) the tap would only work on prime
b) it would tend to cutout on tickover, except with choke, because it would be drawing extra air in.

If the carbs weren't overflowing before, then it's most probably crud blocking the float valve. The only way to tackle that without stripping the carbs is to tap the body of the carbs with a small hammer.

If it's not an easy fix, then you need to do this properly.