Idle problems after a day of work - help? (LONG)

Hey guys. I've had my '82 xj650j for few years, but I've just now found the site. I'm about to put a little work and money into my bike to make it a little nicer.

I pulled my carbs 2 days ago, replaced the foam pod filters that were on the bike w/some k&n type pods, replaced the manifold rubbers, sprayed out the carbs w/carb cleaner (used a whole can), and degreased/washed the engine and under-seat area. I also removed the remnants of the stock airbox that had been partially cut out by PO to accomodate the foam uni-filters.

So when I started bike, it took a while to start. I figure this is mostly due to empty carbs. I had the pcv(?) hose plugged with a bolt. (I realized that was not going to work after I got it started for a few seconds and heard hissing air from the hose.) After I removed the plug and started it, there was a noise coming from the engine that sounded like a plastic squeak...(not grinding or anything) It was coming from one cylinder only, and the engine was missing terribly. After about 1 1/2 minutes, it sort of smoothed out and the squeak was mostly gone. Could this be fuel in the oil? And if so, how would it have gotten there? It's not squeaking any more.

Now it runs pretty strong under throttle, but won't idle for more than about 30 sec w/choke completely off. I would think that it just needs rejetting, but it had pods on it when I bought it (and a 4-1 exhaust), so I would think it has already been rejetted. It idled before I changed the pods, but I'm thinking cleaning the carbs may have caused a vacuum leak somewhere? Is that possible? I didn't take them apart, just sprayed them out liberally. BTW: I checked the battery, and it holds 9.9 volts while starting, so I figure that's not the idle problem.

Also, does anyone have a suggestion for what to do with the pcv hose that is now going nowhere? I'm guessing I should put a valve on it?

 

Is it the crankcase vent (that went into the stock airbox?) If so then put an air filter on it to get crap out of the crankcase and tie it up inside the bike near where it used to be.

Strange sounds like that one don't sound good...

You could easily need to rejet - the old air box might have been providing some restriction... also the carbs now could be flowing better. For a better answer on this let it idle 30 seconds and then turn it off, check your plugs. They'll tell you what is going on.

 

Won't the filter on the crankcase vent tube get plugged up with oil?

If it is running lean, how will I ultimately know if I need to rejet? Sorry if this is a stupid question. I have no experience w/carbs, really.

 

The crankcase vent is only to maintain atmospheric preasure inside the crankcase. If you put it high enough very little oil will get in it and it'll function happily.

Jetting these bikes is a bit of a chore - more than one person has ditched the pods and gone back to stock. You certainly can do it - but you'll have to do some trial and error.

First off - you can check your mixture at idle by letting it idle, turning it off and checking your plugs. If they are black you're rich, brown you're about right, and white/light you're lean.

You should adjust the mixture (rejet) if the plugs aren't the right colour, you notice flat spots, or no one wants to ride behind you

 

Here's a good description of carb tuning ( on a 250 )... the idea is pretty simular. More to come on this as we're doing a much better FAQ entry for this as I speak.

http://forums.ninja250.org/viewtopic.ph ... 005#364005