McCulloch Chain Saws

[willysmn]

tight piston

Are they the correct rings? If the ring grooves are not deep enough, then the ring would look OK while just sitting on the piston in the expanded state, but when compressed might not be able to go back into the groove enough to allow the ring to compress. Or if the groove was carboned up behind the ring....same effect.

 

[promac850]

Are they the correct rings? If the ring grooves are not deep enough, then the ring would look OK while just sitting on the piston in the expanded state, but when compressed might not be able to go back into the groove enough to allow the ring to compress. Or if the groove was carboned up behind the ring....same effect.

I will double check that tomorrow. I was thinking maybe someone either mislabeled the rings or some kind of mix-up occured somewhere. Just for chits and giggles, I will put the old rings on and see if they do the same thing. Also, another check will be putting the piston in w/out rings. Will post more tomorrow.

 

[willysmn]

Tight piston

I think you will find it tomorrow.

 

[a. palmer jr.]

I will double check that tomorrow. I was thinking maybe someone either mislabeled the rings or some kind of mix-up occured somewhere. Just for chits and giggles, I will put the old rings on and see if they do the same thing. Also, another check will be putting the piston in w/out rings. Will post more tomorrow.

After a lot of use there is a carbon build-up under the old rings. I always took an old ring and broke it in half and used it to scrape the ring grooves. I'm thinking that maybe you need to do that also.

 

[Mr. Bow Saw]

The rings fit perfectly on the piston, the ends are equally spaced from the locating pins.

What do you mean? At or from the pins?

Do you have the ends at the locating pins?
Some rings are tapered at the ends to fit up to the pin.
Are your that way?

 

[promac850]

After a lot of use there is a carbon build-up under the old rings. I always took an old ring and broke it in half and used it to scrape the ring grooves. I'm thinking that maybe you need to do that also.

I did, maybe not well enough. Will also check that tomorrow. Hopefully I can get the engine together and start cleaning up the rest of the parts, then assemble the saw. Murphy's law most likely will not allow that though. :deadhorse:

 

[promac850]

What do you mean? At or from the pins?

Do you have the ends at the locating pins?
Some rings are tapered at the ends to fit up to the pin.
Are your that way?

No, I meant as in they are the same distance away from the pins. There are no tapers on the ends of the rings.

For example: -|- The two dashes are the ends of the ring, and the vertical line is the pin. There is maybe .010" or so of space between the each end of the ring and the pin.

 

[stinkbait]

I will double check that tomorrow. I was thinking maybe someone either mislabeled the rings or some kind of mix-up occured somewhere. Just for chits and giggles, I will put the old rings on and see if they do the same thing. Also, another check will be putting the piston in w/out rings. Will post more tomorrow.

Do you have the spark plug in? The resistance you feel at the top may be compression. Take the plug out and see how smooth it cycles.

 

[cpr]

Yep. I've started selling, trading, and giving away saws, parts, and projects lately. More will go soon. Cutting loose what doesn't 'fit' my collection. Trying to recoup some badly needed space, and gather a little parts $$$. Sold the 031AV that I've had for 24 years! That means the only creamsicle left in the stable is your favorite model Charles! Did you get what I sent you yesterday?

Oh.....................and what's "BTHP"???

Yup, I got it. Thanks.

BTHP = Boat Tail Hollow Point, my preferred bullet design in the rifle.

 

[promac850]

Do you have the spark plug in? The resistance you feel at the top may be compression. Take the plug out and see how smooth it cycles.

Nope, spark plug is not in.

 

[promac850]

Good news! I got the engine together!

The problem with the piston sticking towards TDC was caused by me not doing a good enough job cleaning the carbon out of the ring grooves... moral of the story... make sure you clean those :censored: out. Now it moves freely.

Forgot to bring the camera in to post pics... sorry, that'll have to wait about an hour. (RTV has to cure a little bit, then I have to go out and tighten the bolts.)

Yay!!! Getting there!!

Thanks for the help guys!

 

[leeha]

(RTV has to cure a little bit, then I have to go out and tighten the bolts.)

Yay!!! Getting there!!

Thanks for the help guys! [/QUOTE]



I think you would want to tighten all the bolts
right after you assemble the cases. Then let it
cure for awhile.
What are you using for sealer?
Some RTV sealers are not that good with gas.


Lee

 

[stinkbait]

I would think that letting the rtv set up before you tightened the cases would cause some problems.

 

[Ambull]

How could they be hard to get on? I thought you just have to line up the holes and slide it on, then put the bar on, followed by the outside guide piece. I never heard of it being hard to put guides on, pics would show me why it would be so.

You are right, they are not that hard. Just an extra step. Whenever the chain tensioner is in the clutch cover, it makes things a little more of a challenge to line up, but obviously nothing that can't be overcome. Now back to my first question, why do we need the chain guides in the first place? Is it mostly when I am using a longer bar? Is it to protect the operator in case the chain is thrown? Is it to deflect wood chips? Is it to prevent the saw from throwing the chain?

Anyways, those answers are what I am looking for.

 

[nmurph]

chain guides help keep the chain on the sprocket and in the groove when trash gets caught in the chain, or when the chain gets torqued and is trying to jump off the bar.

 

[Eccentric]

Yup, I got it. Thanks.

BTHP = Boat Tail Hollow Point, my preferred bullet design in the rifle.

10-4. I wasn't making the connection. Just thinking of communication terminology. BTHP is indeed the way to go if you want to "reach out and touch someone." Not planning any of those "liquidations" I hope....

 

[cpr]

10-4. I wasn't making the connection. Just thinking of communication terminology. BTHP is indeed the way to go if you want to "reach out and touch someone." Not planning any of those "liquidations" I hope....

No. Although the guy who hit my wife and daughter this am had my blood boiling.

They're fine so he gets to eat without need of a straw, Jeep's not, but his Mustang looks way worse :msp_angry:.

 

[Eccentric]

No. Although the guy who hit my wife and daughter this am had my blood boiling.

They're fine so he gets to eat without need of a straw, Jeep's not, but his Mustang looks way worse :msp_angry:.

I understand completely. The Explorer was tagged pretty hard by an uninsured 'homeless' broad while Jenn and the girls were in it a couple of months ago. That God they weren't hurt. I had feelings similar to yours.

 

[nmurph]

...They're fine..........

glad the familiy is ok.....metal can be replaced, family can't

 

[promac850]

I think you would want to tighten all the bolts
right after you assemble the cases. Then let it
cure for awhile.
What are you using for sealer?
Some RTV sealers are not that good with gas.


Lee

I would think that letting the rtv set up before you tightened the cases would cause some problems.

I'm using the Permatex Ultra Grey. The instructions on the back of the tube said "Assemble while wet, finger tighten all bolts; let it sit for an hour, then torque bolts down." That's exactly what I did. Some other RTV's cure differently. I don't know what Motoseal's procedure is, nor Yamabond or Hondabond, etc. I do know what Ultra Grey's procedure is. Every RTV and sealer is different.

Here's the link to the RTV I used: http://permatex.com/products/Automo...gid_High-Torque_RTV_Silicone_Gasket_Maker.htm

One of the other members here recommended it.