Mastermind meets the Dolmar 7900

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And stucco. Glad it was not in a conspicuous place on the side of the house where I started in with my "new" 250. That thing sounds like a dirt-bike. I love it. It is kinda tough to run at a very light throttle, though. I find mine 4-strokes heavily just off idle.

Randy, I think we have another vote for a Stihl fs250 build.
 
Are you planning on going with a 79 or 84 cc kit or just modding the 6401 to see what you get? either way I've been looking at doing either or! And this thread makes me want to tear into it! Just wondering what your plans are!?!?!

nate

Gonna see what I can do with the 64cc top end first.
 
That is definately the 7900 I sold to a fellow AS Member. Very interested in seeing how it turns out.

Ding, Ding, Ding Bigred you are correct.

Randy, looks like a fine saw, can't wait to run the beast. I have a special patch of woods on my farm for this saw.:msp_biggrin:
 
The first didn't hold near the RPMs in the cut.

Brad as you know things aren't always what they seem in videos, maybe he was pushing harder because of the chain, or whatever. My point is, it's pointless to really judge a saws power or rpm's without a tach, timed cuts and equal chains, or actually being there and running the saw IMHO. That's why I asked Randy.:msp_smile:
 
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Brad as you know things aren't always what thy seem in videos, maybe he was pushing harder because of the chain, or whatever. My point is, it's pointless to really judge a saws power or rpm's without a tach, timed cuts and equal chains, or actually being there and running the saw IMHO. That's why I asked Randy.:msp_smile:

My comments were based on RPMs held in the cut by the same operator and timed cuts in the vids.
 
Here they are together. Someone time them:)

[video=youtube;C7O0RQ0BxWY]http://www.youtube.com/watch?v=C7O0RQ0BxWY[/video]

[video=youtube;V9skmQuOPpM]http://www.youtube.com/watch?v=V9skmQuOPpM[/video]

Dolmar 7900 with a windowed piston. Same numbers as the other saw. I did file the chain though. :)

[video=youtube;WyFQBUgLAx4]http://www.youtube.com/watch?v=WyFQBUgLAx4&list=UUg2yelCeKwB12xIohZfmf1g&index=1&feature=plcp[/video]
 
There is no mistaking the difference in RPMs in those two vids. Don't need a tach to hear that:cheers:

Well I must need a tach:msp_wink: because I don't hear much difference lol. This is the first video of Randy's 7900 build, to me it Sounds the best.

Edit Brad posts too fast.

<iframe width="420" height="315" src="http://www.youtube.com/embed/C7O0RQ0BxWY" frameborder="0" allowfullscreen></iframe>
 
Hey Mastermind..... I'm calling you out! I was just wiping down all my saws and I got cheated out of a sticker on my Dolly 120si!:msp_sneaky: Dont let me forget it when I come to pick up the 044 and blower.
steven
 
Well I must need a tach:msp_wink: because I don't hear much difference lol. This is the first video of Randy's 7900 build, to me it Sounds the best.

Edit Brad posts too fast.

<iframe width="420" height="315" src="http://www.youtube.com/embed/C7O0RQ0BxWY" frameborder="0" allowfullscreen></iframe>

You caught me before I edited my post, lol.

I just went back and timed them. The windowed piston saw is faster:rock:

Non-Windowed
4.20
3.58
3.46
3.61
3.63
3.47

Windowed Piston
3.57
3.29
3.32
3.31
 
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Well I must need a tach:msp_wink: because I don't hear much difference lol. This is the first video of Randy's 7900 build, to me it Sounds the best.

Edit Brad posts too fast.

<iframe width="420" height="315" src="http://www.youtube.com/embed/C7O0RQ0BxWY" frameborder="0" allowfullscreen></iframe>

7900's are just freaks...
And stuff...
:rock:
 
You caught me before I edited my post, lol.

I just went back and timed them. The windowed piston saw is faster:rock:

Non-Windowed
4.20
3.58
3.46
3.61
3.63
3.47

Windowed Piston
3.57
3.29
3.32
3.31

1st cut must be thrown out, two knots............:ices_rofl:
Also... Did Randy say he touched up the chain in the 2nd set of vids?
:confused:
 
1st cut must be thrown out, two knots............
Also... Did Randy say he touched up the chain in the 2nd set of vids?
:confused:

No but he said that the chain in the first one had not been sharpened in some time and that with the first video each cut he leaned on it progresssively harder.
 
Post # 150 of this thread (by Mastermind)

The videos are uploading.

The first cut was really light handed, then I added a bit more force each cut. It's pulling an 8pin and that chain ain't been sharpened in some time......

The second video is after a bit of tuning. It seems to be pretty strong but what do I know?
 

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