Dolmar Specs

[buckwheat]

I was checking out the Makita/Dolmar saws and was curious about the specs on the three new saws. The 6400/6401, 7300/7301, and the 7900/7901 are all identical in appearance and are listed at 13.6 pounds. Are they all basically the same frame with just different displacement?

How hard would it be to swap out the piston and cylinder on a 6400 to upgrade it to a 7900? Is there any difference with the bottom end?

 

[Tony Snyder]

Why not just buy the 7900 in the first place?

Do you already have a 6400? Are you trying to sneak into the under 4 cube class at the local Fair?

I got a customer that has a 2171 Jonsered with a recoil side cover that says 2165? Wonder why he would have done that?

 

[buckwheat]

Why not just buy the 7900 in the first place?

That part is more hypothetical, Tony, but fact of the matter is there have been a few almost new 6401's on eBay lately going in the $300 range. If its just a matter of putting on a piston and jug with some carb adjustments to make it a 7900, its certainly worth pondering over.

 

[glens]

One (Dolmar) or the other (Makita) website (or both) have the parts diagrams and part numbers if I recall correctly.&nbsp; Here's <a href="http://www.dolmarusa.com/upload/docs/995700059.pdf">one</a>.&nbsp; A quick look in that 769,973 byte file indicates that the part number for the cylinder/piston/ring combinations are all different for the three size saws while all the other parts in close affinity are common.&nbsp; Including the complete crankshaft and gasket.

Glen

 

[Jacob J.]

If the stroke length is the same, you're halfway there. Then you just need to worry about deck height. The way to do this is to acquire the measurements from the top of the wrist pin channel to the top of the crown on each piston. That way you'll know if they take same squish.

 

[dozerdan]

Hi
The 6400,7300,7900 all use the same crank,case,muffler and the exact same carburetor.The only difference in the saws is the bore size.
I also stock 7900 pistons and barrels.
Later
Dan

 

[highmark1]

Dolmar Crank Bearings

From everything I've read and heard about dolmars has been great, but I talked to a builder who told me that there is a problem with the crank bearing on the mag side of the saw. After some time was put on the saws(8-10 so far) all had the bearings wiggling. Any comment? I would like to have one of these 7900's but not if there is a problem with the crank bearings.

 

[dozerdan]

highmark1
A lot of things on your above post really don’t make any sense.
If a saw is going to be sent out to a builder, it is usually done while the saw is relatively new. Dolmar saws have a one-year warrant unless you try to repair it yourself.
If the saws in question did have a bad bearing, it would be replaced under warranty before the mods are done on the saw.
Do all Dolmar saws have bad bearings? Not likely.
Have that builder send me one with a bad bearing; I would like to see what happened to it.
Most of the time the clutch side bearing will fail before the mag side.
Later
Dan

 

[Dolmar_Tech_Mgr]

The Dolmar saws are designed in 'families" with parts interchangeablility as the key feature. The only different parts between a 6400 -7900 are the cylinder, piston and ring. You can then easily upgrade the 6400 to a 7900 with the purchase of a cylinder and piston assembly 038130030.
Terry