064/056 mag11 build

[Frank bierce]

Here it is with less muffler opening

Man...that is snappy!!

 

[Time's Standing Stihl]

14,700 is good! Sounds healthy Jason

 

[srcarr52]

Wasting fuel out the exhaust with too large of outlet. You need more blowdown time.

 

[awol]

It doesn't take a special size,just less than 2 giant openings

If opening the muffler to much slows the saw down, I think you've either went to high and wide with the transfers, or not high enough with the ex. Muffler restriction is never a good thing for performance.

 

[jmssaws]

Without my notes in front of me I think it has 23 to 25 degrees of blow down.

I'm not really restricting the muffler,it's still very open but not 2 1x2"+ holes.

 

[jmssaws]

I just took my 066 that Shaun ported and dall's 066 and put this muffler on and killed both.
All 3 with different porting but all 3 have big transfers so it has to hurt how it feeds the cylinder.
I wonder if a stock airfilter will produce the same results?

 

[jmssaws]

This saw came to me with machine work and a 288 piston.
It was 100 124 82 and it ran pretty good but stopped at 13.4k,it also had stock ports. I changed crank seals thinking it was a airleak when I ported it,after porting it ran fabulous but stopped at 13.4k
It's 99.5 121-123 82 now.
Definate Daves 066 i just did is 99 122 81 and ported exactly the same and will 4stroke past 15k like most I port do but it has a smaller outlet on the muffler.
I pulled the screens on my 066 Shaun ported and killed the rpm on it.

The tight transfer saws I use to build liked as big as you can get but these saws die without back pressure.

I'm not talking about it running better with a stock muffler,I'm saying they run better with a little less.

In that video it has the same carb settings as the other video where it stops at 13.4k
All I did was put a stock 066 red light muffler on it and it gained 1300 rpm.

 

[Stihlbro]

I've never seen one do this and I've had 4 in the last 2 months.
I threw parts at 2 of them till they were fixed but I don't know what fixed it for sure.
It runs as good as any I got here but absolutely stops at 13.4

Threw parts at it till it was fixed.

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.

Tried coils and carbs.

My 064 did the same thing and I finally found a small airleak,and I mean exactly the same thing down to the exact rpm.
It's fixed but I can't find a airleak on the saw in the video,with a lot of air in it under water I can't find one.

Had a air leak.

Nope.
I'm convinced it has a airleak even if I haven't found it yet.

Can't find the air leak?

I think it's a crank seal that only leaks at high rpm.

So to conclude, the air leak was in the muffler.

 

[jmssaws]

Threw parts at it till it was fixed.



Tried coils and carbs.



Had a air leak.



Can't find the air leak?



So to conclude, the air leak was in the muffler.

I'm sorry for taking up your time and I should have taken your advice and plugged some dumaflauchy in the carb.

I definitely did change parts on my 064 till it was fixed, it's faster to eliminate trouble when you have 10 of the same saws that work fine to swap parts around on.

I wouldn't have considered the muffler but it's the only thing left I didn't change,I'm sure I can put it on another saw and it work fine just not this one.

Again I'm sorry for not taking your advice about fixing the carb problem.

 

[MustangMike]

Boy did I get trashed (on a previous site) for suggesting that more may not always be better regarding opening up the muffler. Any exhaust on any engine will work best when the "pulses" are in sync, and the only way to get there may be experimenting. More opening may be better on some engines, but not necessarily on every engine.

044 #1 did not like the modified dp cover I put on it. The idle became erratic and throttle response suffered. I put a stock dp cover on it and it was fine, and put the modified one on the 046, which liked it and liked it even more when I opened it even further. Every saw is different.

 

[paragonbuilder]

I'm sorry for taking up your time and I should have taken your advice and plugged some dumaflauchy in the carb.

I definitely did change parts on my 064 till it was fixed, it's faster to eliminate trouble when you have 10 of the same saws that work fine to swap parts around on.

I wouldn't have considered the muffler but it's the only thing left I didn't change,I'm sure I can put it on another saw and it work fine just not this one.

Again I'm sorry for not taking your advice about fixing the carb problem.

Parts swapper... Lol


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[Lightning Performance]

Anybody ever have a saw that won't go past 13.5k? Run strong and idle good but no matter what it won't go past 13.5 or even 4stroke at 13.5
Screw the carb screws shut and it won't go past it. I've had 4 saws like that and fixed 2 but don't know what I did to fix them. I figure it's a airleak but can't find one in a bucket of water. Anybody?

I'll jump in on that. Had several different types of engine do just that. They also had different carb manufactures. The only thing we found out was that the no go carbs had bad flow characteristics above a given RPM. There was no "fix". If it don't flow it won't go. Jet changes did nothing. Adjustments did nothing. Found this one time on a small 2smoke carb. Many 4smoke small engines have this problem. Most times the carb was just too small to feed the new build. That's all I have for ya.

Try those carbs out on a bone stocker and see if they respond to adjustments. Ours did but they still sucked. Lazy with little response to any adjustment. Sledge hammer fixed that right

 

[RI Chevy]

Bar kicker.

 

[jmssaws]

I got the factory port opened out to the deflector and a stock dp cover on it and it will tune over 14.5 it's 14.3 here

 

[jmssaws]

I advanced the ignition and ran the 064/056 some. I'm still limping it at 12k but it's still strong, the rpm don't change much.

 

[Lightning Performance]

Listen at it the first time I check rpm,it's fat at 13.3 but I heard it start leaning and let off. Anybody else hear that?

yes

 

[paragonbuilder]

I got the factory port opened out to the deflector and a stock dp cover on it and it will tune over 14.5 it's 14.3 here

So does it only effect no load tune? Or is it also weaker in the wood ?


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[Chainsaw Jim]

I used to get brow beat whenever I would bring up tuning a stock muffler with port location and size.

 

[Lightning Performance]

I was not getting the "Full Monty" there. Did not really understand your "condition" until I read all the way through the thread.
Wow!

That is one strange characteristic of a loop system ain't it LMAO. I should have been thinking about Jimmy aka Merl's 115 Rude with shaved 140 heads (smaller chambers) killer reeds and a port clean up. We did just as you, chased everything around on it to no end. I'm going to stop and say:

This was a two year endeavor to find a vicious hidden problem on ONLY this engine. So, in the past we built dozens of them from 115-140 and mixed and matched *s-word just like J does! That said, THIS sob drove us CRAZZZZY! You feel me? Good.

Then we drink and say WTF??? Tell others at the bone fire. Everybody's got an opinion just like ... OK so, We tried 1 1/4" carbs 1 3/8" carbs and 1 1/2" carbs no difference. This is after we changed everything twice from parts and running stuff. As J every damn part worked great on every other engine. We had four to six any given day to test on. We adjusted everything in the carbs and the ignition timing. We just knew something was wrong at the top end. It was flat and the tac stopped just like J's did. We lost the go at 5'400. It was flat as a pancake!!! It was a pure pig until we closed down the 2x2" holes in the back of the mid case. He bought the boat with that mod already done to that mid-case but it used to have a 140 power head on it. We would have never thought in a million years it mattered that much. 1 1/4" carbs will break your neck on the hole shot with the extra exhaust holes plugged. One hole and she runs right up through 7,000 with no lag,with every carb set. Lesson learned. Never take anything for granted when it is not NOS bone stock.

Basically we missed the boat, pun intended, on those two "extra" big holes. You gave many people here an important lesson today! Nice job

 

[Lightning Performance]

So does it only effect no load tune? Or is it also weaker in the wood ?


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On our build it just killed it at 5400rpm. We think the low pressure pocket enhanced the poor conditions of the loops end cycle. We were also @ 65mph when it came up. We changed the prop to go bigger. Same thing at 68mph. It stayed all through a 25px4 @72mph. Made you say Whaaaaat? 5400wtf? Whaaaat... Change the damn tac. OK done. Same same Scratch head again... Rinse repeat