Project Stumpbroke Dolmar PS-540

[Stumpys Customs]

This was a fun build. I was given free reign to do whatever I wanted as long as it was still able to be used for fire wood duty.

It's a really clean specimen.

Not real impressive stock though, but still a well built 54cc saw.
[video=youtube_share;7pDrWhJ7UEM]http://youtu.be/7pDrWhJ7UEM[/video]

 

[Stumpys Customs]

One hurdle to over come was the piston skirt was to short to lower the cyl any. I found that a 029 piston would work. The skirts are longer & the deck height is a lil bit taller. I only used the top ring & re-located the locating pin to center, more on why later.

Another drawback is it has open transfers, I am pleased to see that they do have plenty of volume though.

The squishband was cut.

Plenty of room for improvement on the intake side.

Same goes for the exhaust side of things.

 

[moody]

Looks like a pretty solid base to start from.

 

[Stumpys Customs]

Here's the reason for centering the ring. I also didn't go as wide as I ad it marked since It would have went through on the outside.

Exhaust side

 

[Stumpys Customs]

Looks like a pretty solid base to start from.

Yep, they are a very sturdy built saw.

 

[Wagnerwerks]

I'm super new to porting, but I'm ecstatic to see an open port saw getting a work over. Can you explain the intake side a little? I'm not looking for trade secrets, but I'd love to know more.

Nice!!!!!

 

[Stumpys Customs]

The induction got an upgrade too. I originally fitted it with a carb from a 372xp, but it ended up being too much. It now sports a walbro HD off of a Stihl MS290.

Here's the 372 carb.

And the 290

The swap was pretty easy. The throttle linkage worked just fine with a lil tweaking and used the choke lever from a 372. I had to remove some material from the plastic base around the carb. I also had to install an external impulse line. The intake block & air filter base had to be opened up considerably to match up with the bigger carb.
When I switched to the 290 carb all I had to do was swap the throttle & choke shafts to the 290 carb body.

 

[Stumpys Customs]

I'm super new to porting, but I'm ecstatic to see an open port saw getting a work over. Can you explain the intake side a little? I'm not looking for trade secrets, but I'd love to know more.

Nice!!!!!

What ?'s do you have about the intake side?

 

[mt.stalker]

:msp_thumbsup: Finger ports

 

[Stumpys Customs]

The muffler needed some attention too, very choked up.

I split it & cut the tubes off of the baffle so it will be an open can. Also opened the existing outlet.

I tig welded it back together and added a second port to the side.

 

[sunfish]

Nice!

Hedgerow's saw? :msp_sneaky:

 

[Hedgerow]

That's a sexy saw right there...
Just sayin'....

 

[Stumpys Customs]

Here's the fruits of my labor. not a mindblowing gain.
[video=youtube_share;oGPr2QbBNFU]http://youtu.be/oGPr2QbBNFU[/video]

 

[Stumpys Customs]

Nice!

Hedgerow's saw? :msp_sneaky:

Maybee..........................

That's a sexy saw right there...
Just sayin'....

I thought you'd like it.

 

[atvguns]

Nice!

Hedgerow's saw? :msp_sneaky:

Way to go let the cat out of the bag:hmm3grin2orange:

 

[atvguns]

Stock 27.87
with Stihl Piston 19.20:msp_thumbsup:

It liked that grabby chain alot better after the port job:msp_thumbsup:

 

[Stumpys Customs]

Stock 27.87
with Stihl Piston 19.20:msp_thumbsup:

It liked that grabby chain alot better after the port job:msp_thumbsup:

I wondered who would be the first to comment on the Stihl parts:msp_tongue:

 

[DB43725]

Nice job Stump...you helped that saw a buntch. Have to call that one a Dollie on Stilts} :hmm3grin2orange::hmm3grin2orange::hmm3grin2orange:

 

[Hedgerow]

I wondered who would be the first to comment on the Stihl parts:msp_tongue:

It's just a good thing it's not a Stihl OEM piston... Or it would cut slower...
And stuff...

 

[mt.stalker]

7 secs. is a nice gain . Do you think the finger ports helped ? Good to see someone massaging an open port saw too !