64/73/79 Dolmar Buildoff Saw Thread MMWS 2019

Howdy!

So, I've convinced myself to save enough cash to attend a GTG next year. It's a big feat being that the travel is so far, but we'll manage it. I've also convinced myself that I should build a saw for that GTG to compete against everyone planning to enter the buildoff.

I've built quite a few saws and learned a ton about them, but I've never even come close to building a competitive saw. I do some porting on my own saws, but I don't own a lathe or mill, so most of my work is done with manual methods or common tooling to any homeowner.

With that being said, I'll log my progress here and upload pics as I go. If i'm slacking and not uploading pics, please kick me I may be sleeping. Lol.

If anyone has any questions along the way, give me a shout.

Cheers,
Dan

The saw...

 

It's a little rough, but not too bad overall.

 

Cool..

Cooler..

Frigid..


Looking forward to all of the above

 

First, the teardown...

PO used a regular nut for replacement bar nut.


Chain catch has taken a beating. IIRC I have one somewhere.


Some chain rash under the clutch cover, but it looks decent enough to use.

 

Under the top covers...

Older red top versus newer black top...
2003 PS6400 Dolmar versus



2007 PS630 Dolmar - the newer models have some pre-filter material similar to Frogzskinz...


PTO side...


Clutch appears solid...


Oil tube shows some leakage...nothing Yamabond shouldn't take care of...

 

mmmmhh Dolmar

 

I'll be following along on this thread .

I love my dolkita 6421. Stock for stock it's faster and lighter than my buddy's 460 magnum.

 

Well, it appears someone has replaced the coil at some point.

This saw has the black coil that is limited to lower RPM's.

Typically the 6400's had a maroon coil that is higher RPM.



Oops. Doesn't look like the sparkplug boot was installed correctly.



This one has the Zama C3M carb. Model 11A, I believe.


Carb removed. Pretty clean overall for a 2003 saw.



Old style cylinder with decomp on the flywheel side....


Edit: and yes, that is electrical tape on the plug wire. It looks like it was too short and they taped on an extension.

 

Muffler removed.




Flywheel off...


Time to get rid of this black coil....found a new maroon one out of Estonia on eBay.

 

Piston and cylinder and seals on order.

Starting to do some mods while I wait for parts...

Fitting a Red97 large deflector where the small Dolmar one once was.

 

That'll wake up the neighbors. I'm amazed at how loud my cat equipped muffler is on my saw. It's so much louder than the 460 mag.

 

Lol. It will be a bit loud and I've made some changes that will make it even louder.

 

Some more muffler mod pics...

I drilled the temporary rivets after fitting the deflector and opened the can up with propane torch and screwdrivers.

Here's the birdcage....I'm totally removing this gadget.


I cut the welds free with a cutting disc on my angle grinder.


The birdcage slides free of the mount posts.


Front of the muffler inside view with all the garbage removed.

 

I opened the exhaust inlet and port matched it with a ported cylinder I already have...


I opened the exhaust outlet to about 80% of exhaust inlet...


This is the flange I cut off the bird cage. It is also port matched and will be brazed around the exhaust inlet for support....

 

I'm just here for the

 

Was that a cat equipped ss muffler? Or was it the older non SS one without the cat?

 

It's a non-cat, but I think it's the galvanized version.

 

Here's a look at the old cylinder. Open port design on the 6400. 47mm bore and 37mm stroke.

I'll be going with a closed quad port design cylinder for the build.



Intake boot setup.


There was some scoring on the old piston....

 

More to come Scotty....