Checking For Intake Leaks

I just got my xj550 last week (1982 SECA) and I notice that the rubber boots on the carbs are a bit aged.

When I used to work on cars, I used to spray a little carb cleaner around the carb and intake and vacuum lines to check for intake leaks. Would it be alright to spray carb cleaner on the rubber boots and see if it speeds up at all, meaning I have a leak? Will the carb cleaner hurt the boots at all?

The bike runs pretty good, but it seems to spped up and slow down quite a bit while I have the choke on when warming it up. I can't seem to get it to stay steady. I have to keep messing with the choke lever to keep it running at about 3000 rpm. Sometimes it will reev up to 4200 and then down below 2000.

IS this typical of these bikes?

 

I would not spray carb cleaner on the intake boots. It has a really bad effect on rubber and plastic parts. Basically it'll eat it away. And no one wants that to happen.

I suggest doing what I like to do. I use a propane torch, unlit of course. I just turn it on, run the motor, and pass the torch across anything that I feel might be causing an intake leak. If there is a leak, your motor's rpms will increase.

 

You are being serious right.

I don't want to be one of those guys you read about or hear about on the radio that did something realy stupid.

It makes sense.

 

WD40?

 

Yes I'm serious. I use this exact method to chase down vacuum leaks on my 300zx. Yea, it's a vacuum nightmare.

 

Yep, this works. Propane is a good check for leaks. To keep the boots in shape I spray them with Armorall.

 

How about starting fluid? or any spray for that matter? For those that don't have a propane torch...

Would any fluid be enough to notice a vacuum leak?

 

Yes any of those will work for an obvious leak. The good thing about propane is that it is a gas so therefore it will get sucked in if in the vicinity of the leak where a liquid needs to be sprayed right on the leak. So if you soak the seals down that works fine but does leave a mess.