064/056 mag11 build

[jmssaws]

I've had 4 different 066's that all stop at 13.4
Lots of coils and carbs and lots of different ignition advances but still won't go. I can take a carb off a saw that will go to 15k and it's the same thing, 13.4
Once a saw stops 4stroking you can still generally keep gaining rpm but these completely stop at 13.4 and 4stroking up to that point then it's over.
I'm thinking it's the muffler opening to big but I haven't tried it yet.
My 064 hybrid that would tune to 14.5 done it and I changed everything twice and it fixed it.

 

[Stihlbro]

So your saying you can close the high side needle off and the saw won't go past 13k? Sounds like, the loop scavenging is stuck.......

 

[jmssaws]

So your saying you can close the high side needle off and the saw won't go past 13k? Sounds like, the loop scavenging is stuck.......

There is nothing you can do to get it past the rpm it stops at and all 4 I've seen do it are almost exactly the same rpm,right at 13.4k
2 of the saws I ported and 2 I didn't.

 

[Stihlbro]

I had a husky 268 do that once, and I raised the transfers and it come around. Not the case here, but it obviously getting fuel to run up to that, even with the hs closed off. If it were me I'd look to restrict the topend fuel. The fuel supply is not matching the porting characteristics.

Take you a piece of lead(fishing sinkers work) and close off the fixed jet for the main nozzle. See it the saw will run off the other part of the fuel circuit.

 

[Deets066]

I had a husky 268 do that once, and I raised the transfers and it come around. Not the case here, but it obviously getting fuel to run up to that, even with the hs closed off. If it were me I'd look to restrict the topend fuel. The fuel supply is not matching the porting characteristics.

Take you a piece of lead(fishing sinkers work) and close off the fixed jet for the main nozzle. See it the saw will run off the other part of the fuel circuit.

Does the bypass circuit flow more or less than the main jet? .....generally

 

[Stihlbro]

Depends on the carb and size of jetting. In this case it is supplying enough to run the saw up to 13.4 with the hs closed off. The question is once closed off, as long as the feeder to the hs will supply enough. Hopefully it does not block off all.

 

[Stihlbro]

If you have a #68 jet in, and the saws tunes out say, 1 and 3/4 turn out. Change to a #74 and you have to move the hs to one turn out. See the correlation?

So in jms scenario, he could from a #68 to a smaller. Removable jet if possible. Solder the jet and resize. Epoxy, lead, stake with a punch or something.

 

[jmssaws]

If you have a #68 jet in, and the saws tunes out say, 1 and 3/4 turn out. Change to a #74 and you have to move the hs to one turn out. See the correlation?

So in jms scenario, he could from a #68 to a smaller. Removable jet if possible. Solder the jet and resize. Epoxy, lead, stake with a punch or something.

I've had every possible carb and jet combination on them.
All of them tune around 1 and 1 and the low and high tune like they should but they stop at with no 4 stroke at 13.5

 

[Stihlbro]

Well..... Screw the out the wood rpm, how does it cut?

 

[jmssaws]

Well..... Screw the out the wood rpm, how does it cut?

They are strong as any of them.
I ported dall's 066 and it will tune up towards 15k,cfb's 066 is exactly like it but won't tune at even stock rpms,my 064 hybrid would tune over 14.5 then did the exact same thing but I somehow made it better.
Any one of the right ones will still gain rpm even if it's not 4stroking but these saws 4stroke hard 13.3 and none at 13.4 and nothing will make it go past that.

I got a video,give me a minute to load it

 

[Chris Zautner]

They are strong as any of them.
I ported dall's 066 and it will tune up towards 15k,cfb's 066 is exactly like it but won't tune at even stock rpms,my 064 hybrid would tune over 14.5 then did the exact same thing but I somehow made it better.
Any one of the right ones will still gain rpm even if it's not 4stroking but these saws 4stroke hard 13.3 and none at 13.4 and nothing will make it go past that.

I got a video,give me a minute to load it

Time for a 084 carb yet?

 

[Deets066]

If you have a #68 jet in, and the saws tunes out say, 1 and 3/4 turn out. Change to a #74 and you have to move the hs to one turn out. See the correlation?

So in jms scenario, he could from a #68 to a smaller. Removable jet if possible. Solder the jet and resize. Epoxy, lead, stake with a punch or something.

I understand the jetting well, it's the bypass circuit that confuses me, why is it even there? And can that be blocked off and run main jet only?

 

[jmssaws]

It's at 13.3 when I start then I turn the high in almost a half turn then it's at 13.4 and zero 4 stroke

 

[dall]

jason do you want to try my carb on that saw and see if theres a difference ?

 

[Deets066]

Maybe your trans are flowin more than you have incoming air, pull the filter off

 

[RI Chevy]

It's at 13.3 when I start then I turn the high in almost a half turn then it's at 13.4 and zero 4 stroke

Motor still sounds good though.

 

[Stihlbro]

Take a tillotson hs carb, some are called governored. The bypass is to keep,the saw from going too lean. Often the governored circuit gives too much fuel, so that circuit can be blocked off. The saw will tune off the hs needle and you have control of the tune. You can lean it out so to speak.

The wj's have a fixed jet to supply fuel to the main nozzle. You can richen up more by the hs adjuster. If you close off the hs adjuster, the supply of fuel is still available to the main nozzle by the fixed jet.

I just watched your video, I don't know what your tach says, but when you leaned it out. I can hear a distinct increase in rpm. Do you have another tach to try? Tach or not, if the saw is four stroking and cleans up in the cut, and comes back to a four stroke out of the wood is what I would be concerned with. I have a edt7 that the response time is slow, I personally don't like to hold a saw wide open waiting on it to register. The edt 8 is better but I don't use either anymore. It is just a reference. Tune that saw in the wood.

 

[jmssaws]

My tach is very good.
The saw gained almost 200 rpm is all.
I've had the filter off and every carb I have on it. It is not the carb.
There's 4 066's in the floor that will go past 14.5 and I've had everyone of there carbs on it

 

[RI Chevy]

What type of muffler Jason? If it isn' t the carb, maybe the muffler? Or an intake boot sucking air? Or bad fuel line or fuel filter?

 

[dall]

al needed to change the filter and line on my 036 because it was lacking rpm and leaning out