Lakeside53
Stihl Wrenching
He said 11%... not a big gain considering the cc etc. Of couse, I'm not the guy to ask. I could care less if I cut a log in 20 or 22.2 seconds 
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Porting the 361 Big Bore
- Thread starter blsnelling
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Lakeside53
Stihl Wrenching
WOT is only an indicator. Doesn't mean much if you raised the exhaust roof and killed compression to get them. I don't really think RPMs in the wood counts either. The BB is faster because I can push on it harder than the OEM. The OEM would stall if I pushed as much as I am on the BB. It just like the 7900 Slingr built. If I don't really load it down, I saw >13K in the cut with a square ground chain in a different log last night.
They are screamin'!
Actually, the only thing that matters is the rpm in the cut.... What you can maintain at optimal pressure... and that gives the best cut rate and time...
13k not loaded isn't meaningful... what is it "loaded" and cutting best?
stihlboy
Guess who's back
na andy it is only if your chain is sharp as demonstrated at the GTG
Lakeside53
Stihl Wrenching
stihlboy
Guess who's back
Oh sorry.. I forgot about POSERS
excuse me??? are you calling brad a poser????
windthrown
361 Junkie
We all know what really matters in the cut!
Its what oil is in the saw! :greenchainsaw:
Its what oil is in the saw! :greenchainsaw:
stihlboy
Guess who's back
gary gravy
Why of course. It was Stihl bar oil!!!!! And Klotz R50 @ 40:1 in 100LL.
yo2001
ArboristSite Operative
So what do you think about going 20 deg blowdown on a work saw? In cuts?
That's exactly what this saw has. Exhaust at 100* and transfers at 120*.
yo2001
ArboristSite Operative
Right. So what you think of it mr.Snelling? Is it much gain? Narrow powerband or broad? I wanted to know the pros and cons if you don't mind.
There isn't a hint of peakiness in the powerband. You'll notice several different in the cut RPMs in the video I poseted. I was not only looking to see which would yield the fastest times, but also demonstrating how broad the powerband is. It pulls VERY strong. I'm definately impressed.
I just put a 460 carb on the 361BB. It won't idle at all. It's not trying to race like an air leak. It simply won't run that slow and shakes like crazy. Rev it up and it smooths out.
What does the little replaceable jet near the needle valve control? Is that the fixed portion of the high side? I swapped that out with the one from the 361 carb and it got worse. I was only guessing anyway.
I borrowed the choke shaft from the 361 carb to get the correct arm orientation. I had to widen the flat spot for the 460 choke plate to fit in it. I also had to open up the impulse passage and use the bottom plate from the 361 carb. Other than that, it was a direct bolt on.
So what might be the idling problem and how to fix it.
What does the little replaceable jet near the needle valve control? Is that the fixed portion of the high side? I swapped that out with the one from the 361 carb and it got worse. I was only guessing anyway.
I borrowed the choke shaft from the 361 carb to get the correct arm orientation. I had to widen the flat spot for the 460 choke plate to fit in it. I also had to open up the impulse passage and use the bottom plate from the 361 carb. Other than that, it was a direct bolt on.
So what might be the idling problem and how to fix it.
Lakeside53
Stihl Wrenching
The idling problem may due to way too much gas, or an imbalance in the L circuit (pressures, venturi etc.). The L path to the progression bores in late model HD carbs (361, 460, 290 etc) has a check valve, and it's not replaceable.
You might be better trying an early model 044 carb.
You might be better trying an early model 044 carb.
Thanks Andy. This is a HD16 carb. Funny you mention the 044 carb. That's what I put on my 260 and it runs like a dream. No one problem since the first startup with it.
flyboy
ArboristSite Operative
Time for a dyno? That would give you all your data and then some.
I bet you could make more $ with this thing then the payments would be.
http://www.land-and-sea.com/kart-dyno/kart-dyno.htm
I bet you could make more $ with this thing then the payments would be.
http://www.land-and-sea.com/kart-dyno/kart-dyno.htm
Bluemaxpilot
ArboristSite Lurker
Yep time for a Dyno....it's only $99 a month!!!
You would be the only one on the block with one.
Yep time for a Dyno....it's only $99 a month!!!
$99 down,$99 a month for 99 months!
