Received Asian MS440 Big Bore Triplets Today

[huskyboy]

I think the early zama is better quality and maybe jetted differently?

 

[Terry Syd]

The earliest C3Ms on the 044 were a different carb, they weren't twin jets, they used a 'Walbro' type jetting. The C3Ms on the 365 were twin jets, but had been compromised by the EPA.

I've done up a twin jet for the 365 and a couple of BB 372s. When modded, the twin jet is a super carb, but stock they are way too lean in the low speed circuit (thanks EPA).

It was interesting to see that the Husquvarna engineers took off the HD 12 and put a modded Zama on their factory ported 372. They also used a gutted high top filter and made a high flow foam filter out of it. There was a video of it a while back.

 

[MustangMike]

Well, I think I resolved the carb issues on saws # 2 + 3 today, making them both "good to go". I put a rebuilt ZAMA C3M carb on #2, and the choke works perfectly! There must be a subtle little difference between the choke levers on the ZAMA and Walbro carbs. (Note: The ZAMA carb does not have a snorkel, so the inlet for the snorkel got plugged).

On saw #3, I installed a rebuild kit on the carb that came with it, and so far it seems to be fine.

I need to do more testing on them, but I think both of them are now good to go.

I still need to pull the jug on saw #1 and lower the intake, and I may also add some bridge ports. The carb on that saw had not given me issues, but if it does, I know what to do! Even though #1 had the best BB jug to begin with (IMO), I was timid about lowering the intake my first time around, so I think this is what it needs. As a reminder, I moved it from 64 to 72.5, but I don't think that is enough to make it run like I want it to run.

As I have stated before, this was a learning process for me, and my first exposure to porting. It has been interesting.

 

[MG porting]

Well, I think I resolved the carb issues on saws # 2 + 3 today, making them both "good to go". I put a rebuilt ZAMA C3M carb on #2, and the choke works perfectly! There must be a subtle little difference between the choke levers on the ZAMA and Walbro carbs. (Note: The ZAMA carb does not have a snorkel, so the inlet for the snorkel got plugged).

On saw #3, I installed a rebuild kit on the carb that came with it, and so far it seems to be fine.

I need to do more testing on them, but I think both of them are now good to go.

I still need to pull the jug on saw #1 and lower the intake, and I may also add some bridge ports. The carb on that saw had not given me issues, but if it does, I know what to do! Even though #1 had the best BB jug to begin with (IMO), I was timid about lowering the intake my first time around, so I think this is what it needs. As a reminder, I moved it from 64 to 72.5, but I don't think that is enough to make it run like I want it to run.

As I have stated before, this was a learning process for me, and my first exposure to porting. It has been interesting.

Very cool glad it's going you're way this time like to see them all lined up in a photo shoot. Lol.

 

[MustangMike]

Ran saws 2 + 3 a bit yesterday. Noticeably more vibration than from a standard 440. Any one built a kit without going big bore? Are they smoother?

 

[MG porting]

Ran saws 2 + 3 a bit yesterday. Noticeably more vibration than from a standard 440. Any one built a kit without going big bore? Are they smoother?

The one I built had a big bore on in also it vibrated I changed out the av bushings for oem Stihl ones seamed to help mine a bit.

 

[J_M____]

My big bore has some vibration. I think I’m just going to swap on a oem jug.

 

[smokey7]

If i remember right just bout every 440 build thread ive read talked about extra vibes. I would suspect the 20 dolker crank first. I bet you (mike) have some oem ones to compare. If you have v blocks a indicator and a scale we can find the problem. I tried 3 china cranks on 625 630 670 saws and all had excessive run out and 1 was majorly out of phase. Let us kbow what you find out

 

[T.Roller]

I'd say it has alot to do with the av too

 

[MustangMike]

If you have v blocks a indicator and a scale we can find the problem

That is a little beyond me.

I'm guessing a cheap crank, cheap AV and heavier piston = more vibes.

I thought these would be my favorite builds, but I'm starting to like the 660 knock offs more and more each day!

Wonder if there are any cheap AM cranks that are better? I know I like the HL Supply chain adjusters (only about $8).

Also seems like we had a lot more builds and feedback on the 660s.

 

[MG porting]

That is a little beyond me.

I'm guessing a cheap crank, cheap AV and heavier piston = more vibes.

I thought these would be my favorite builds, but I'm starting to like the 660 knock offs more and more each day!

Wonder if there are any cheap AM cranks that are better? I know I like the HL Supply chain adjusters (only about $8).

Also seems like we had a lot more builds and feedback on the 660s.

Lol. Yea there's something about a 90cc verses a 70cc that gets the blood flowing.

 

[MustangMike]

They also seem to be more similar to OEM.

 

[MG porting]

They also seem to be more similar to OEM.

Yea not to bad but still have there problems but not a big deal oem parts bolt right on if needed.

 

[J_M____]

I think hl supply has some Taiwan made cranks that look a bit better than the Chinese stuff

 

[MustangMike]

Well, I guess I did not do too bad on my Asian Big Bore builds. A local tree guy ran BB #3 at his job today, and he wants to buy it.

Said even though it had some vibs, he liked the power to weight.

I also picked up a 12 mm 044 case, P + C yesterday, so the case P +C on saw #1 may get replaced with this OEM stuff. Was very surprised the P+C looked so good. I suspect this saw may have gotten the tank holder crushed prior to the AM tank holders being available.

If you had to purchase OEM tank holder, top handle, recoil and plastics, that would make it not worth fixing. IMO, I was real lucky to get this, guy initially told me he had a 460 parts saw for me. This is much harder to find.

 

[MG porting]

Well, I guess I did not do too bad on my Asian Big Bore builds. A local tree guy ran BB #3 at his job today, and he wants to buy it.

Said even though it had some vibs, he liked the power to weight.

I also picked up a 12 mm 044 case, P + C yesterday, so the case P +C on saw #1 may get replaced with this OEM stuff. Was very surprised the P+C looked so good. I suspect this saw may have gotten the tank holder crushed prior to the AM tank holders being available.

If you had to purchase OEM tank holder, top handle, recoil and plastics, that would make it not worth fixing. IMO, I was real lucky to get this, guy initially told me he had a 460 parts saw for me. This is much harder to find.

Niiicce. That should be a good build for you. And very cool on saw three glad it terned out so are you going to sell it to him? Lol.

 

[MustangMike]

Yep, I don't really need 3 extra saws, and my CFB Hybrid will out run them, and is smoother.

I've also got 3 046/460s under way. Two of them running, but parts are still on order. One is a D jug, one a Hemi, and one is a HL Supply AM jug (deal of the day). Looks real nice for the money, but I was not impressed with the piston, so I used a Meteor. Got it running 2 days ago, but have not put it in wood yet, and I'm waiting on parts for the chain brake.

Then, I plan to do a build that I will keep, in conjunction with Dr Al. Details to follow!

 

[MG porting]

Yep, I don't really need 3 extra saws, and my CFB Hybrid will out run them, and is smoother.

I've also got 3 046/460s under way. Two of them running, but parts are still on order. One is a D jug, one a Hemi, and one is a HL Supply AM jug (deal of the day). Looks real nice for the money, but I was not impressed with the piston, so I used a Meteor. Got it running 2 days ago, but have not put it in wood yet, and I'm waiting on parts for the chain brake.

Then, I plan to do a build that I will keep, in conjunction with Dr Al. Details to follow!

Right on can't wait.

 

[MustangMike]

Well, the tree guy I sold BB #3 to today stopped by and paid me, and he is very happy with the saw. I previously did a muff mod and timing advance on one of his 460s, which he said really woke it up, but he says the 440 big bore easily out runs it, and it a good deal lighter. (I lightly ported the BB cylinder, and did not do any port work to the 460).

Hey, I'm glad he is happy, and I hope it continues to run well for him.

 

[MustangMike]

In other news, BB #1 was the most "lethargic" of the 3 BBs that I did, likely because I left the intake too high. However, I also did not like the increased vibrations (of all 3 BBs).

So today I pulled the P+C off #1 and replaced them with an OEM 044 piston + cylinder. It is a straight fin cylinder, apparently made by Stihl (not Mahle). I tried to measure squish (while it was still on the original case), but my .050 solder did not give a reading. Found out there was a .040 gasket under that cylinder … no wonder!

W/O a base gasket, on an Asian 440 case, squish is .018 and the numbers were unimpressive … 103, 118.5 and 68. I planned to raise the ex a hair, and lower the intake, but I guess I did not remove enough for the Ex # to change (I was being a little cautious with an OEM cylinder).

I ended up with 103, 118.5 and 79. She fired up and ran nice (right before dark), hopefully I will get to put her in some wood tomorrow, and hopefully that annoying vibration will be gone or reduced.

FYI, the OEM 044 piston is 2.5 oz, the BB New West Pistons are 3.0 oz. That is a 20% increase. If you use the AM piston pin (I didn't), you add another 0.2 oz.

Will be interesting to see how this thing cuts compared to BB #2, which felt about the same as #3.