PITA TK 22 - 1982 550 LTD

Hi everyone, I thought I would give you an update. I have good news and bad news. The good, the carb that had the plugged pilot circuit is working great. However, now I am having issues with #2 cylinder firing. I holed this piston last year because of running lean, but have found the culprit and replaced it (boots between head and carbs).

So, what it is doing now is not firing at all when the bike is first started. It doesn't fire under open or closed throttle. I can get it to sputter a bit by turning the air/fuel mixture screw ALL the way in (which makes it richer I think, right?) Once the bike warms up though, it fires.

I have checked the plug, wires and compression (130 psi,has been climbing due to valves and new rings seating in). My only idea is I tried to bench synch the carbs this weekend before putting them of the bike and vacuum synching them. I had some trouble getting all the slides to go completely shut with the main idle knob adjusted all the way out (so I would have some adjustment on either side of the knob). So maybe I need to see if maybe #2's is goofy or something.

Other than that, I'm not sure why it will sputter when I screw the mixture screw all the way in. Any ideas?

Sounds to me like the pilot jet got partially clogged. Also have cou held up the carbs to the light to check if all 4 slides are at the same height? They may need syncing.

I'll make sure I inspect the jet when I pull them off. What is a good method for bench synching (I got the vacuum part down).

I just backed my idle adjustment all the way off where it hits and then adjusted each slide down so I couldn't see any light shining through. I then turned my idle adjustment knob in so all 4 came up equally and allowed a little bit of light to shine through. I further adjusted the knob once I got the bike to start.

BTW- I epoxied my choke flappers (I wasn't nimble enough to fab new doors) and they kick @ss! She turned over twice and fired from being dead cold and just pulled apart. It has never ever ever started that nice before. It actually took me by surprise!

apbling wrote:

I'll make sure I inspect the jet when I pull them off. What is a good method for bench synching (I got the vacuum part down).

I just backed my idle adjustment all the way off where it hits and then adjusted each slide down so I couldn't see any light shining through. I then turned my idle adjustment knob in so all 4 came up equally and allowed a little bit of light to shine through. I further adjusted the knob once I got the bike to start.

BTW- I epoxied my choke flappers (I wasn't nimble enough to fab new doors) and they kick @ss! She turned over twice and fired from being dead cold and just pulled apart. It has never ever ever started that nice before. It actually took me by surprise!

Sounds like you have the bench sync method down pretty good. That's the way to do it.

Glad to hear the epoxied flaps worked so well. You are at least the second or third member to confirm this method works well for starting.

One of these days I want to look into getting all-new choke plates made with no flaps at all. That way no metal parts can get sucked into the motor.

Can't remember if I gave you this link yet. It's to help control the fast-idle setting while on choke.
home.comcast.net/~loudgpz/GPZweb/Carbure...PZchokeScrewMod.html

Yeah, I had my fast idle set a little too aggresive when I first started it.... She roared to life pretty quickly!

If the pilot circuit isn't plugged, I'll be at a loss. I'm pretty sure it's clean and the bench synch was good, but I'll double check. Just seems odd that after it warmed up a bit it was firing. I did pull the plug one time after it was not firing and it was wet...

Which carb had the plugged idle passage? Is it the same one that is not firing now?

also, I see you lined the tank. Make sure none of the liner made it to the carbs. That could explain a clogged pilot.

Have you checked the float levels using the clear tube method? That should be done to be sure there is the right level in each carb. I check it while idling so vibration will be present.

Since the plug was wet with gas, it could also be electrical. Do you have a timing light? That could help identify a dead spark circuit. If #3 is firing, then the coil is ok so it would be a shorted plug wire or plug on #2.

Well, #4 had the really bad plugged passage, but its good now. 2 is the cylinder I hole last year. While dealing with #4 over the past month or so, #2 has always been ok.

I did check the fuel service level with the clear tube. Odd enough, 1,3,4 were all a bit low so I raised the levels. #2 was spot on.

#3 is firing. I did not check for spark on #2, just switched the plugs. I was going to check for spark, but then it started to fire, so I assumed it was sparking (unless running like a diesel )

Maybe I bumped something getting my tank on and the spark is just weak enough it isn't enough to fire while cold, but once the head/cylinders heat up its good enough to get it to fire?