Loud valves, erratic idle, sooty exhaust...

[Mick77]

  (91 B4 nonvvt) Ok, I've done several days worth of digging around the site, and have read most of the relevant posts, but just to be sure I don't miss something I decided to go ahead and throw this one out here and cover all my bases.  I did a valve adjustment the other day, and the world fell apart.  As the subject line reads, there are my problems.  It will run fine on startup in the morning, with less choke than usual for less time.  Runs great until about 5 min later when I get to the stop light.  Then it's up and down idle, if you blip the throttle, it will go so far down RPMwise that you think its gonna stall... so to keep from killing it in traffic I crank up the idle screw a bit.  well, that makes it stick higher than i set it after a crack of the throttle... and a few minutes later, back to the bogging.  Runs fine on the freeway, can't really feel any flat spots other than the normal one around 6 or 7k.. i think.  I KNOW i got my specs right on the valves, I checked them twice, but now I'm second guessing myself.  It has NEVER been that loud as far as the valve noise goes.  I know they're kinda loud, but this is different.  SO, tomorrow, I'm taking it apart *again* and THIS time I'm gonna clean the carbs too. (I learned this the hard way: always do this when adjusting valves... you're already all in pieces anyway, right?  Now for the questions.  I have never tuned carbs.  I have read a lot in the last few days about the clip position, the turns out, and all that.  Mine says in the manual that the pilots are pre-set.  Does that mean screw them in til they gently stop?  I've never lookedat clip position, should i mess with it?  (factory jets, new 0rings, supertrapp exhaust, K&N filter) Is 2.25 turns out on the mix right?  Why oh why must it be so finicky... Until tomorrow neighbors.

[tomacGTi]

You are aware that you have to rebalance the carbs after a valve adjustment right?

If you pulled them off to do the VA, you may have knocked around some dirt, etc in the carbs clogging up the works. Instead of fretting about the VA (should sound like a typewriter anyway) do a carb clean and synch and then get back to us.

-Randy

[PitterB4]

100% agree with Randy.  Sync the carbs before tearing into things again. 

BTW - "the pilots" and "the mix" as you used them above are the same thing.  Yours were preset at the factory but are now 2.25 turns out...

[Mick77]

Ok, so I tore everything apart before I read your posts.  But hey, small price to pay for a little peace of mind.  At least I can stop second guessing myself and prove that I did it right the first time .... Well, carbs are off now and I'll give 'em a good talking to and put them back on.  I'm hoping that I can rent the synch tool somewhere, or find someone that has one.  I dont have the extra bux to buy one. (any of you in the Austin TX area?)  While I have everything apart, should I be leaving the clips in the same position that they are in?  Just curious.  I don't have a proper shop, so I'm gonna leave it until daylight tomorrow in case something gets dropped (not the bike this time, lol!)  That way I can read here before putting it all back together.  Thanks for being here fellas, I really appreciate this board and everyone on it!
 

[tomacGTi]

Search the boards on how to make a DIY synch tool aka manometer. I made one that connects all four carbs at once and it cost me a whopping $8 to build. Or you can get the tool, they both accomplish the same thing.

The jetting database is pretty good these days to give you an idea on jetting. If you don't have a jet kit with that combo you're running, you're going to be really lean. I think interfuse was running a setup very similar to yours.

Make sure you throw a fuel filter on the line as well since you're cleaning the carbs.

When I did my first valve adjustment/carb synch oh so many moons ago, it was the single biggest difference I ever made to the bike engine-wise. Well, a tie between that and blowing my motor up.

[Mick77]

Jet kit... I'm pretty sure that the previous owner changed the jets now that i think about it.  He gave it to me with about 3 different sets.  He couldnt get it to run right, and didnt have time to mess with it.  It was the ugly duckling in his barn with his 3 other bikes.  I know for sure that it doesnt run lean though, so yeah, jet kit probably.  NOW, in other breaking news: Source of noisy valves discovered, sooty exhaust explained... you guys will probably kick me from the board for this one... I read my feeler guage wrong!  Totally wrong, looked at the inches instead of the mm.  I thought that those extra zeros looked kinda strange.  So the Intake was at about .25 instead of .1 (or whatever, cant remember) and the exhaust was at almost .4!!  Jeez, am I glad I decided to double check.  Always go with your gut I guess.  Speaking of guts, You guys think I did any *real* damage?  As far as the carbs go, I'm leaving them alone on the inside for now.  I'll just set them to the 2.25 and go from there.  I've read the post on the DIY guage, but I'll have to revisit it, as it was over my head then.  Sorry to have gotten all stirred up about something that was really nothing   We'll see how we run tomorrow and go from THERE. 

[r_outsider]

The bike should be fine. Setting valves too loose in the short term should just make them noisy. Although the B4 has got to have one of the loudest valvetrains ever made to begin with.  As for your mistake, people make mistakes every day. Those who don't are either lying or not trying hard enough.

[Red01]

people make mistakes every day.
Those who don't are either lying or not trying hard enough.

...or they work in Quality Control.