066 Carb issues.

[betterbuilt]

I have a 066 that chasing my tail with. I basically have a new bottom end on it and I have a new top end on it. I can't get it to tune.

Can someone tell me if I'm doing something wrong with how I pressure testing it. I bought a whole Box of pressure test fitting off the Bay a while back. I blocked of the muffler and blocked off carb with a pressure test fitting. I thought it was leaking towards the back of the carb but it turns out the H screw is leaking. I'm not sure but that seems bad. Is there any repair for this? I see in the blowup there is a seat in there. Is it the problem? I ordered a carb just so I'm sure to get it running again but I'd like to salvage this one if it's possible. Okay lay it on me.

 

[mtngun]

Not sure I understand your question clearly, but normally when I leak test a saw, I block off the muffler, block off where the carb normally bolts on, and connect the vacuum or pressure line to the saw's impulse line.

The carb is not normally part of the saw's leak test, so I'm wondering why you think your carb is leaking at the H screw ?

Are you vacuum testing or pressure testing ? I usually vacuum test first, if it passes, I give it a green light. If it flunks the vacuum test, then 5 -10 psi pressure and a squirt bottle of soapy water will find the leaks.

 

[gink595]

I bought a pressure tester from EC and it showed where the air leaks were coming from in the multiple 084 carbs I had and couldn't get one to work. Within a few minutes of owning the tester I found all the problems I was having with each carb. It was stupid stuff like a leaky diaphram or needle not seating correctly.

PopOff Guage 0 to 15 [POPG-1] - $31.03 : EC Distributing, Your Online Racing Store!

 

[JDNicol]

I have a 066 that chasing my tail with. I basically have a new bottom end on it and I have a new top end on it. I can't get it to tune.

Can someone tell me if I'm doing something wrong with how I pressure testing it. I bought a whole Box of pressure test fitting off the Bay a while back. I blocked of the muffler and blocked off carb with a pressure test fitting. I thought it was leaking towards the back of the carb but it turns out the H screw is leaking. I'm not sure but that seems bad. Is there any repair for this? I see in the blowup there is a seat in there. Is it the problem? I ordered a carb just so I'm sure to get it running again but I'd like to salvage this one if it's possible. Okay lay it on me.

Block off behind the carb i.e. carb not included in test and see if saw passes the tests. Proceed from there.

I bought a pressure tester from EC and it showed where the air leaks were coming from in the multiple 084 carbs I had and couldn't get one to work. Within a few minutes of owning the tester I found all the problems I was having with each carb. It was stupid stuff like a leaky diaphram or needle not seating correctly.

PopOff Guage 0 to 15 [POPG-1] - $31.03 : EC Distributing, Your Online Racing Store!

You are talking about pressure testing the carb i.e. via the fuel line but it's all good :msp_smile:

As opposed to the OP trying to test the saw with the carb included. I believe the carb will always leak around the throttle/choke shafts.

 

[betterbuilt]

Not sure I understand your question clearly, but normally when I leak test a saw, I block off the muffler, block off where the carb normally bolts on, and connect the vacuum or pressure line to the saw's impulse line.

The carb is not normally part of the saw's leak test, so I'm wondering why you think your carb is leaking at the H screw ?

Are you vacuum testing or pressure testing ? I usually vacuum test first, if it passes, I give it a green light. If it flunks the vacuum test, then 5 -10 psi pressure and a squirt bottle of soapy water will find the leaks.

That's why I posted the question. Well I tried blocking it at the manfold and that was good but I thought you could pressure test with the carb installed. I wasn't sure I was doing it right. I figured it would hurt it.

So what I'm asking does air pass freely through the H screw?

 

[betterbuilt]

As opposed to the OP trying to test the saw with the carb included. I believe the carb will always leak around the throttle/choke shafts.

Well that's good to know.

 

[betterbuilt]

I kind figured I was testing it wrong.

I have a leak and I think it's behind the carb but I can't figure out how to get it to seal any better.

 

[gink595]

You are talking about pressure testing the carb i.e. via the fuel line but it's all good :msp_smile:

As opposed to the OP trying to test the saw with the carb included. I believe the carb will always leak around the throttle/choke shafts.

That's exactley what I'm talking about as I stated in my orginal post, if you are having carb issues you want to test the carb not the crank seals

 

[mtngun]

I have a leak and my think it's behind the carb but I can't figure out how to get it to seal any better.

Leak on the saw or leak on the carb ?

Asking questions is good, we're all here to learn.

 

[betterbuilt]

Leak on the saw or leak on the carb ?

Asking questions is good, we're all here to learn.

I guess I was typing and on the phone and what I wrote didn't make any sense.

I tested the saw and the manifold for leaks and it's good. I'm concerned that the leak is behind the carb where the carb meet the manifold. I'm getting closer to getting this thing thing running again but I'm just trying to figure out how to be sure of where the air leak is.

 

[gink595]

Fill the kitchen sink full of water and submerge it and start putting pressure to it. Worked for me a couple weeks back

 

[Jacob J.]

If you've assembled the saw correctly, and the carb is butted up against the rubber manifold lip in the airbox, it shouldn't be leaking. I've never seen an 064/066 that leaked where the carb meets the intake boot.

 

[betterbuilt]

If you've assembled the saw correctly, and the carb is butted up against the rubber manifold lip in the airbox, it shouldn't be leaking. I've never seen an 064/066 that leaked where the carb meets the intake boot.

I even took it apart again and put another new manifold on it. I did another pressure and Vac test and it came out good. If it's a carb issue It's getting out of my realm of knowledge. I dropped it of at the shop to see if they can figure it out. I'm sure I'll get it back with the same problems.

Here's what it was doing:

I took it out yesterday to run some fuel through it and see if I could get it to run while in the cut. I got it running pretty much where it was supposed to with a tach. I watched it as the Rpms would keep creeping up and then it just wouldn't stay at WOT. When you hit (out of the wood) the throttle it would spike to about 12900rpms and then it would bog down. I have to admit I can't hear well enough to tune a saw by ear so I'm relying on the tach to get it close. Then I was attempting to tune it in the cut but I couldn't get to run with out acting funny.

Thanks for the help so far.

 

[betterbuilt]

Fill the kitchen sink full of water and submerge it and start putting pressure to it. Worked for me a couple weeks back

I have a laundry sink that I use to see if I have any leaks. I'm glad I didn't try putting it in the sink with the way I was attempting to pressure test it. The case would have been full of water. I'll probably order one of those pop off tester so I can test carbs myself.

 

[mtngun]

it would spike to about 12900rpms and then it would bog down.

Could be an air leak.

Could be starving for fuel (clog somewhere, or torn fuel line).

Could be a loose flywheel, too, since you mentioned that you'd rebuilt the bottom end. If the flywheel shears the key, it may run, but RPMs will be crazy. That happened to me recently.

 

[gink595]

I was at Eric Copseys house a couple weeks back and I was working on my Husq. 50. Eric suggested that we pressure test it before we try running it especially on Alky. So we did and seen there was a leak but couldn't locate it so we went in the house and put it in the sink and found it at the impulse nipple I relocated in the case, about 5 hours later we had it fixed

 

[betterbuilt]

Could be an air leak.

Could be starving for fuel (clog somewhere, or torn fuel line).

Could be a loose flywheel, too, since you mentioned that you'd rebuilt the bottom end. If the flywheel shears the key, it may run, but RPMs will be crazy. That happened to me recently.

This saw is driving me crazy. I'll check the key. I kinda doubt that's the problem but I'll check it anyways. I've had one of those flywheels that actually split at the center and the hub would move freely from the other part and it would pop but it wouldn't start.

The fuel line and impulse are new. I think I need learn more about the carbs like pulling the welsh plug but I've been a little worried about ruining a carb. I guess it's not gonna hurt at this point. The shop said to pick it up on Monday. We'll see if I missed something.

 

[gink595]

The pressure gage I posted is the bee's knees for pointing out air leaks in a carb. I was pulling my hair out with a 084 I rebuilt, all the carbs I had wouldn't work, Eric even sent me one and it had a leak. Once I got that gage, I was able to pinpoint all the problems with each carb. I don't think I could live without one, it will take a lot of headaches out of trouble shooting.

 

[betterbuilt]

The pressure gage I posted is the bee's knees for pointing out air leaks in a carb. I was pulling my hair out with a 084 I rebuilt, all the carbs I had wouldn't work, Eric even sent me one and it had a leak. Once I got that gage, I was able to pinpoint all the problems with each carb. I don't think I could live without one, it will take a lot of headaches out of trouble shooting.

Is there anything else I should order to go with that pop off Guage? Does it come with testing instructions?

 

[angelo c]

I had one leaking in the plastic connector block in the fuel line. I pressure test everything before it goes on the saw, new, old or borrowed.
As JJ said the carbs for the 66's are pretty stout. Never had one that couldn't be corrected. ( clearly not a 200t carby)

I might also figure out a way to seal up the intake hose and pressure test that as well. Did I mention pressure test everything???

Are you sure you have the metal ring holding the intake manifold seating correctly and in place ?