Still Won't Idle! I think I'm done.

[UncleMike]

Well, it sure sounds like the manifolds are OK. Only you would know if the carbs are positioned correctly into them and the clamps positioned and tightened correctly. I assume they are.
I'm not sure why you believe the carbs have never been taken apart but I'll have to assume you're right on that too. If so, the diaphragm/spring assembly should be fine since a failure here usually means a lack of throttle response or none at all instead of your high rpm problem.
So you've inherited the problem? No amount of carb or electrical work has any effect.
Have you ever taken a compression read? I'm thinking you may have a leaking head gasket. Has it been replaced or at the minimum, re-torqued correctly? Any visible signs of a leak anywhere?

I don't believe they've ever been taken apart because they still had the plugs over the mixture screws, and none of the screws had any wear at all on them from being taken apart. Just a guess though, and trusting the P.O. when he said they'd never been apart. Stupid, I know.

I've not taken a compression read, but it's my next step. I've just to locate the correct adapter to fit in the plug holes.

The engine weeps oil in several places, but never enough to drip at all. Just get a bit moist. I've tightened some bolts, but not a proper re-torquing.

[KEITH KRAUSE]

I'd first try re-torquing. Wouldn't hurt.
I'm not sure what your head is supposed to be torqued to. It's more precise than most other bolts. Check before torquing. Don't just guess. Use a good torque wrench.
Crack loose the bolts just a little before re-torquing. You can't accurately torque a bolt without loosening it a tad first. The threads should be clean too but I'm not asking you to remove and clean, just crack and re-torque. Hopefully that will be all that's needed.
Do on a stone cold motor. Gradually torque all bolts/hardware in a criss-cross/diagonal pattern, starting at the center and working your way outward. Example: if you have 12 nuts, "top" row is nuts 1 thru 6, bottom is 7 thru 12, sequence would be 4, 9, 3, 10, 2, 11, 5, 8, 1, 12, 6, 7. Torque any outer/smaller (10mm?) bolts last, after the other larger nuts/bolts. Make sure you locate/torque all the small bolts.
Test to see if it helped.

[argonsagas]

I read most of these, Mike, and a simple response came to my simple mind.

Have you balanced all the butterflies? All you need to do (with arbs OFF) is back off the idle screw completely, then look at the butterflies. All should just barely contact the side of the carb. A piece of newsprint can be used to check the closing: if it just sticks, and can still be pulled free, on every valve, you have it right.

I had a similar problem, and fiddled around with cleaning and mixtures until I finally found that solution.

[UncleMike]

I'd first try re-torquing. Wouldn't hurt.
I'm not sure what your head is supposed to be torqued to. It's more precise than most other bolts. Check before torquing. Don't just guess. Use a good torque wrench.
Crack loose the bolts just a little before re-torquing. You can't accurately torque a bolt without loosening it a tad first. The threads should be clean too but I'm not asking you to remove and clean, just crack and re-torque. Hopefully that will be all that's needed.
Do on a stone cold motor. Gradually torque all bolts/hardware in a criss-cross/diagonal pattern, starting at the center and working your way outward. Example: if you have 12 nuts, "top" row is nuts 1 thru 6, bottom is 7 thru 12, sequence would be 4, 9, 3, 10, 2, 11, 5, 8, 1, 12, 6, 7. Torque any outer/smaller (10mm?) bolts last, after the other larger nuts/bolts. Make sure you locate/torque all the small bolts.
Test to see if it helped.

Keith,

I can't tell you how much I appreciate you taking the time to actually go through a theoretical sequence for me. I would have second guessed myself the entire time otherwise. I'll let you know if it helps, and thanks again.

Mike

[UncleMike]

I read most of these, Mike, and a simple response came to my simple mind.

Have you balanced all the butterflies? All you need to do (with arbs OFF) is back off the idle screw completely, then look at the butterflies. All should just barely contact the side of the carb. A piece of newsprint can be used to check the closing: if it just sticks, and can still be pulled free, on every valve, you have it right.

I had a similar problem, and fiddled around with cleaning and mixtures until I finally found that solution.

So, they shouldn't be closed completely with the idle screw off? You're talking about the throttleplates, right?

[r.t.snake]

works for me

Hi Mike,

I had a similar problem with my 550 and posted my best wishes a couple days ago.

Well your posts got me back at it.

It seemed that over and over the suggestion was that all indications were an intake leak. BUT - there was no intake leak. I tried all the usual suspects, and it sounds like you have done the same, so...


IF intake leak = lean condition

what else could make it lean?????

- not enough back pressure seemed like it might be a possibility so I took off my not stock mufflers and shoved on the old beat up megaphones and VOILA!

idle doesn't run up-
a little throttle then the idle falls and doesn't stall

oh happy day!

Don't know if that works for you but it sure made my day I'll tell you!

Good luck,

RT

[UncleMike]

Hi Mike,

I had a similar problem with my 550 and posted my best wishes a couple days ago.

Well your posts got me back at it.

It seemed that over and over the suggestion was that all indications were an intake leak. BUT - there was no intake leak. I tried all the usual suspects, and it sounds like you have done the same, so...


IF intake leak = lean condition

what else could make it lean?????

- not enough back pressure seemed like it might be a possibility so I took off my not stock mufflers and shoved on the old beat up megaphones and VOILA!

idle doesn't run up-
a little throttle then the idle falls and doesn't stall

oh happy day!

Don't know if that works for you but it sure made my day I'll tell you!

Good luck,

RT

Congratulations! Go for a ride!

Unfortunately, I've got the stock exhaust on and the thing is pristine. Looks almost brand new.

I suppose I could cover the ends and see if that helps at all.

Thanks, and congrats again.

Mike

[r.t.snake]

Too bad it was not a solution for you ,

Good luck!

RT

[UncleMike]

Too bad it was not a solution for you ,

Good luck!

RT

I appreciate it regardless. Thanks!

Mike

[Billy Ricks]

Just a longshot here, but you might want to try retorquing the head. Could be a slight leak between the head and the block. Look closely at that area and see if there is any ooze there.

[UncleMike]

Just a longshot here, but you might want to try retorquing the head. Could be a slight leak between the head and the block. Look closely at that area and see if there is any ooze there.

Sure is. Keith mentioned it as well. Gonna grab a torque wrench tomorrow and go for it.

Now, there is a general consensus as to what type of torque wrench is best, right?*

Mike

[Billy Ricks]

Sure is. Keith mentioned it as well. Gonna grab a torque wrench tomorrow and go for it.

Now, there is a general consensus as to what type of torque wrench is best, right?*

Mike

Do you have a manual Mike? You want to do it in the right sequence. It's a good idea to back them off a tiny bit before retorquing.

[UncleMike]

Do you have a manual Mike? You want to do it in the right sequence. It's a good idea to back them off a tiny bit before retorquing.

I've got a Clymer's. Plus Keith gave me a pretty good tutorial a few posts back. Just need to find the torque specs in the manual.

Thanks Billy. I appreciate you sticking with this madness.

Mike

[Billy Ricks]

I've got a Clymer's. Plus Keith gave me a pretty good tutorial a few posts back. Just need to find the torque specs in the manual.

Thanks Billy. I appreciate you sticking with this madness.

Mike

Just hang in there Mike, you'll get it figured out.

[Billy Ricks]

Mike, if retorquing doesn't help I'd be happy to go through the carbs for you gratis if you think they might be the culprit.