064 Mods?

[SmokinDodge]

damn, got me!

Ya, it'll get the ol heart goin when you start seeing that crap on a new purchase but I've allready crawled all over it that is about all that is jury rigged. Easy enough to fix.


Vcallies thank you very much, that was exactly what I needed.

 

[deadtrees]

Gypo, please explain mods

Gypo, when you say thinner base gasket for 20 thou, do you mean .020 squish at the piston top? How do you measure that? It has to be done with the engine assembled and you do not have access to the whole piston top. And you have to find the area where the squish is the least.

 

[Freakingstang]

Gypo, when you say thinner base gasket for 20 thou, do you mean .020 squish at the piston top? How do you measure that? It has to be done with the engine assembled and you do not have access to the whole piston top. And you have to find the area where the squish is the least.

Yes .020 to the squish band.

Check out this thread for detailed pics and info of how to check squish clearance and what it is.

http://www.hotsaws.com/showthread.php?t=171

 

[SmokinDodge]

Yes .020 to the squish band.

Check out this thread for detailed pics and info of how to check squish clearance and what it is.

http://www.hotsaws.com/showthread.php?t=171

Steve could you give up the short and sweet of that thread? Since all the hub bub most realivant info is missing from HS...........

 

[SmokinDodge]

If it isn't blatantly obvious this is my first two stroke project. I have several four stroke running in top shape but these little babies are their own thing. I appreciate all the help I have received this far and if I can bend your ear I could use some more help.

Got a little time today and got the jug pulled. It's my understanding that if a piston is to gall or have transfer it usually happened on the exhaust side of the piston, is this correct? The entire side of the piston on the intake side is rough and decent on the exhaust side. I've got transfer just starting to happen on the intake side of the jug about a 1/4" wide above and below the port. The jug ought to clean up decent, thank goodness.

How much play is allowed on the small rod end/wrist pin? I can hold the rod and just slightly move the piston up and down. I'll get the flywheel blocked and dial indicator mounted tomorrow to check how much "slightly" is. The plan was to clean the piston up and just go with new rings but now I doubt the piston is usable with the play.

Also, the wrist pin is firmly planted in the piston,. How ambitious can I get with the removal with out fouling something else up? Are there needle bearings in this as well?


Hautions is gonna beat me done iffen I don't get off my arse! Any updates on your saw?

 

[hautions11]

064

The port work is done. It consisted of removing 1mm from the intake side of the skirt. Widen the exhaust port to within .040 of the skirt width. I will measure squish and remove the base gasket. Permatex Grey I believe is the goop of choice.

Yes there are needle bearings in a cage in the small end of the rod. Remember, there are circlips holding the wrist pin in place. I just tapped mine out with a wooden dowel, while holding the piston by hand. I have 0 up and down play in my rod while I hold it centered, but someone much more knowledgeable then me can probably give you some #'s.

I will take a couple of pics when I get home to shead a little light.

 

[SmokinDodge]

I had the clips out, but I'm glad your watching me. My dad always said I bare watchin'! :yoyo:

I think it might just be the slack in the needles. I wonder is just that bearing is available or if it would be advisable to freshen up all the bearings. So much for my low budget beater. :bang:

 

[RiverRat2]

Gypo's Minor mods

I guess Im just a dumb red neck cause I must admit im not sure I understand:monkey:

Gypo said "Looking at the intake side of the piston with rings off scribe a line 1mm below bottom of skirt, I am supposing this is with the piston inverted and measuring the 1mm toward the ring groove???? or did he mean above the bottom of the skirt,,, In essence you shorten the piston skirt to increase port timing by 1mm.
and if you use the thinner gasket to boost compression
Then the exhaust to raise or increase that port timing as well would you remove 1mm from the top of the exhaust port????

 

[hautions11]

River,

Take 1mm off the bottom of the skirt ~.040. thinner gasket more compression. since you are only removing let's say a .010 to .015 gasket thickness, you only have to raise the exhaust port that amount to Maintain the same timing.

 

[RiverRat2]

Got it!!!!!! but.... how do you lay out your scribe marks inside the exhaust port of cylinder? or do you just make a pass with the tool and keep checking with the calipers until you attain desired material removed,, What tool do you reccomend??????

 

[rickyrooster]

064 Mods!

I Too Am Working On An 064 Stihl. It Had A Bad Piston And Cylinder. I Found A Good Used Cylinder On Ebay And Have Lowered The Intake .040 Along With Widening The Port .040. Then Raised The Exhaust .040 And Widened It .040 Also. I Blended The Bottom Of The Transfers (dennis Calhoun) Shows This Step In One Of His Posts Over At Hotsaws. If I Cant Find Any Thing Better I Will Probly Go With One Of The Golf Pistons. I Plan On Setting The Squish At .022-.025 And Will Ajust The Tranfers When Figure How Much I Need To Lower The Cylinder. I Have Looked At The Factory Dual Ported Mufflers But Decided The Modify The Original. I Copied The Look Of The Factory Dual Port Cover. I Put The Original Cover On A Surface Grinder And Ground Off The Half Of The Cover Facing The Muffler,leaving The Outside Lip That Bolts The Outter Cover To The Muffler. Then I Cut Out A Flat Piece Of .030 Thousands Blue Hardened Shim Stock To Fit Between The Muffler And The Cover. I Cut A 1/2"x1" Inch Hole In The Shim Stock Locating It So That It Is Under The Remaining Half Of The Original Cover. I Then Placed A Screen Over The Hole. I Dont Expect This To Be No Racer But I Do Hope It Will Be A Heck Of A Lot Better Than It Was Stock. Rick!

 

[SmokinDodge]

Howdy Rick. Got any pics of your mods? Sounds interesting, stick around and keep us posted on the results I would like to make a good thread on the 064's for future reference.

Is there a setting on your software to capitalize every word? It makes my head hurt when I read it.

 

[hautions11]

Center the piston and draw the port on the piston skirt. That will show you how much you cn remove and maintain a .020 to .040 distance from the edge of the skirt. After you know the distance, blue the cylinder face and scribe some lines.

 

[SmokinDodge]

Got the piston pin checked out and it seems I was translating some of the side to side movement into the up and down. All is fine with the wrist pin.

When I first got the saw I ran it briefly, it would hardly idle and never really reved up like it should. If my terms are too technical let me know After the tear down to inspect I decided I had better get it running properly before I do any mods. At least that way I would have a solid baseline i could go back too.

I've dedicated today for getting this thing running properly, stayed tuned more to come.

Which way should the rings go on the piston? I know how they came off but someone was in this saw shortly before I got it and I am suspect of the entire thing now.

 

[SmokinDodge]

Got the answer for the rings, mine were installed upside down. I suspect it was an attempt to raise what little compression they could.

For clarification, there is a small pin in the upper third of the ring groove to keep the ring from rotating and the ends of the rings are beveled to run against this pin. Mine were installed like /0\ and should have been \0/.

 

[hautions11]

That could be part of your problem. I am surprised that it did not break the rings that way. How's the piston and cylinder look? Make sure you check for air leaks, especially in the intake boot etc. I may try to swap out my cylinder and piston this week-end.

 

[Kneejerk Bombas]

This is a good read if your working on your top end:
http://www.cycleimprovements.com/docs/link_pages/017.html

 

[RiverRat2]

Ditto On breaking

That could be part of your problem. I am surprised that it did not break the rings that way. How's the piston and cylinder look? Make sure you check for air leaks, especially in the intake boot etc. I may try to swap out my cylinder and piston this week-end.

Dont know how thy got them to compress worth a flip installed upside down,
Suprised nothing broke or scored ,,,,, amazing

 

[Lakeside53]

I'd check the ring gap (put them in the bore out of the piston.) The might have been old rings with the ends ground down...


One question... and it's not a loaded one... Why did you do all the port work before setting the squish? I would have thought set the squish (particularly if you aren't going to using an oem piston), then work backwards to the other numbers?

 

[SmokinDodge]

Surprisingly enough the rings are the least of the problems right now. The piston and jug are in useable shape, but.........I knew there were too many threads about sour deals right now.....................

I cleaned everything up and put it toghether as it came. Had fuel and oil in getting ready to fire it up and I noticed the chain needed tightened. No biggee I start diging through the crud for the screw and didn't find one. :taped:

Off came the clutch cover and bar to inspect WHY there wasn't a tension screw. I found out why and a lot more when I moved the clutch back and forth a quarter inch. :bang:

This saw started on the fifth pull when I got it out of the box. How I don't know but it did.

It was either the oil worms or grease mites but one of them critters got to my bearings and knocked them plum out. Bad enough that the fly wheel has contacted the coil and the oiler and housing has taken quit a hit. Not looking very good.

It's miller time folks!