Need Help Sourcing Dolmar Cement Saw Cylinder/Piston

Degull · Feb 28, 2006

Hi everyone. Please forgive me for asking about a cement chop saw in an arborist forum, but there are a lot of knowledgeable people here that might be able to help. My Uncle bought a used Dolmar SC7312 cement chop saw and ruined it the first week he had it. He has had no experience with two strokes (city man) and didn't realize that he needed to mix oil with gas for his machine to run happy. He said it ran great for a couple of days but it died all of a sudden (I know you're all surprised, I was too, LOL). I asked him if he added oil to the gas and he admitted that he had no idea that it needed to run with oil in the gas. I feel bad for the old guy since he is acting like he has killed only child.
I pulled the muffler off and it looks like the cylinder and piston are scored pretty bad. I was thinking about just sanding the cylinder and piston for now and install a new ring, but I have my doubts. The engine was not seized. Does anyone know a reputable dealer that will send parts to Canada? I really have no faith in the people up here when it comes to Dolmar parts. There is only one Canadian distributor and they seem to charge whatever they want.

Also does anyone know if the piston and cylinder on the SC7312 is interchangeable with any other Dolmar engines perhaps off a chainsaw. The reason I ask, because this might increase my chances of finding a good used one or old new stock, since there are more Dolmar chainsaws in use than concrete saws. Here are the specs from the manual:

Displacement: 73cc (4,5 cu in)
Bore: 50mm (1,97 in)
Stroke 37mm (1,46 in)

The cylinder/piston kit part # is 394130013
The ring part # is 394132020

The Dolmar SC7312, SC7314, Makita DPC7300, DPC7301, Wacker BTS1030 and BTS1035 have the same engine made by Dolmar but re branded by Makita and Wacker.

If I had more cash, I would just buy the piston/cylinder kit for him, but I'm looking at well over $300 (CND funds). I don't have that kind of cash lying around. This is forcing me to broaden my search. I've spent the last couple of days researching but I've hit the wall. Any help would be appreciated.

Thanks.

Javelin · Feb 28, 2006

I could send you the parts if you need them. The chop saw you are talking about uses the same powerhead as the dolmar ps7300 or makita 7301.

slowsuki · Feb 28, 2006

just here say but seams most people on as say you can reuse cylinder. i do not know about reuseing pison with new ring , but you could try . just be out labor and ring if did not work. save alot of money if it does.i've got a couple saws with pistons that look bad but they keep runing great inspite of.

Degull · Mar 1, 2006

I came across a person selling a cylinder/piston for a different saw. It is for the Makita DPC9500 which has a different displacement but made by Dolmar. I can't physically compare the two because I found it online and the person is halfway across the country. I'd have to buy it first. Here are the specs.

Displacement: 5.8 cu in
Bore: 2.16 in
Stroke: 1.57 in

Don't think this a likely fit, but it would sweet if it did.

woodsjunkie · Mar 1, 2006

Will a 6400 work on this as well?
I know it smaller displacement but should bolt rite up ?

Degull · Mar 2, 2006

I talked to my Uncle and he would not mind a smaller displacement (don't think he would notice the difference). Problem is I'm not sure if the 6400 cylinder/piston will be bolt up. The stroke on both cylinders are 37mm but the cylinder/piston part #'s are different between say a PS6400 and a PC6430. The same goes for the PS7300 and the PC7312 and so on. The PS (power saw) models have the same specs (displacement, bore, stroke etc) as their PC (power cutter) counterparts but the part #'s in the manuals are different. Not sure why Dolmar would have issued the same part two different #'s? Anyone shed some light. Someone has had to come across this before. Thanks for all the help so far!