I hate carbs, or i need valve work

[goat]

well, the saga continues. I got my bike running for a day last week before I decided to adjust the valve clearance. I ended up moving all the shims around and buying a few new ones. They were all off.

I think that my problem continues to be getting the f#$*ing mixture right. Before I adjusted my valve clearance, it would hang a little on idle once it got warmed up and would bog down at low rpms (<3k) but once above 3k performed normally. My float height was ok, and i couldn't get the low rpms to improve by adjusting the mixture screws. I ended up taking all the washers out to improve my low rpm bogging.

Right after I adjusted my valve clearance, my idle was really high and once it warmed up, the idle would hang at about 4k until i gave it some choke. Then it would come back down to about 1.5k until i hit the throttle again. It was still bogging down a little in the low range, but not much. I put washers back in (1 and 2, tried both) with no success. I have the mixture screws in all the way to get peak RPMs at idle (while using the washers), which doesn't seem right to me (w/o washers somewhee around 3-4 turns out; bogging down in the low range).

I also get an occasional sound like there is air (exhaust or fiel/air, I don't know which) going the wrong way. It doesn't pop like a backfire, and it doesn't blow the carbs off, but it does slow the engine down a lot.  I have a yoshi full system, k&n lunchbox pods, 150 mains and 40 pilots.

The exhaust manifold is not leaking. I checked that. Does this sound like mixture issues, an engine in need of valve work or something else that I haven't thought of? I'm about to go officespace on my bike, so any constuctive input would be very much appreciated.

[SPARKPLUG1977]

I HAD THE REVVING PROBLEM BEFORE, TRY SYNCHING THE CARBS.
IT SOLVED THE PROBLEM FOR ME

[Rema1000]

It can't be good having to turn the mix screws all the way in; that could mean too rich.  It almost sounds like with 40 pilots and 1 or 2 washers, you are too rich at idle.  But that should not really be possible, esepcially not with aftermarket exhaust and filter, unless something is blocking airflow (K&N filter with too heavy of an oil might do that... maybe try the old paper filter and airbox and see what happens?).

You mentioned that you took out the washers to reduce bogging at low-end.  If by "low end", you mean below 3k RPMs, that's _really_ low-end!, and you probably only see those low RPMs when you first start moving in 1st.  But that's exactly where the washers are supposed to help, not hurt!

I can maybe commiserate: I have way-oversized pilots and mains, and have no washers at all on the slide; so I should be lean and gutless on the get-up-and-go.  I find that I give the bike more throttle to begin moving than I did when it was stock.  Giving more throttle means that the bike pulls pretty hard, so the friction zone is smaller and touchier.  If I want to start quickly, this works-out pretty well.  However, it's a little more difficult to make a nice slow cruising start.  This could be similar to you... then again, it almost sounds like you're rich, not lean there.

I also get an occasional sound like there is air (exhaust or fiel/air, I don't know which) going the wrong way. It doesn't pop like a backfire, and it doesn't blow the carbs off, but it does slow the engine down a lot.

OK, that is weird!  Maybe, missing crush washers on the exhaust?  But you said you checked that.

[dgyver]

I acquired a set of carbs that had parts of a dyno jet kit installed. The slides had the restrictors installed. I swapped slides and now the high idle hang is gone. The restrictor basically plugs one of the holes in the bottom of the slide.


about the air sound......What do the plugs look like?

[goat]

when i first started out, I was really rich, so they were completely black. Once I got the mixture better, the plugs looked pretty normal (going by the pics in the back of my haynes manual).

I think its an air sound. The way the motor slows, its almost as if a piston hit something. I just think its more likely air/gases escaping somewhere they shouldn't  since I haven't had more serious problems yet.

EDIT: The only hole in the bottom of the slides that has anything is it is the hole for the needle.

[danci1973]

EDIT: The only hole in the bottom of the slides that has anything is it is the hole for the needle.

Here is a pic of my slide - one hole for the needle and another - for vacuum I suppose...



 D.

[dgyver]

......The only hole in the bottom of the slides that has anything is it is the hole for the needle.

There are supposed to be 2 other holes in the bottom of the stock slide. Remove the plug out of one of them so it looks likes danci1973 slide.

[EvilScooby]

I hate carbs myself, gave them up last year and lost 60 lbs

[goat]

I have no plugs on the bottom of my slides. There are three holes. One for the needle, and two that aren't used.

EDIT: the other two holes do not have anything (plugs or otherwise) in them.

[goat]

could the lack of plugs be causing any of these issues? There were no plugs when I opened up the carbs for the first time.