Received Asian MS440 Big Bore Triplets Today

[Deets066]

How wide is the actual squish band?

 

[T.Roller]

I hear you Mason. It is not the squish # that scares me, it is the tiny combustion chamber in conjunction with that squish #.

Hey, just going to give it a try and see what happens!

I'm sure it'll be fine I haven't had one yet that was too bad with a decomp.

 

[MustangMike]

How wide is the actual squish band?

Looks just like an 046 D cylinder.

 

[Wonkydonkey]

I was after Stihl conrod sizes. Guess I should have said ..so. Doh..

 

[MustangMike]

OK, she runs and I'm happy, I think it is both faster and torquer than the previous one. Not an animal, but real nice! I'll take it!

So I guess the first indicator of how today was going to go was when I noticed the crimson streaks on the white case … yea, I didn't even realize I'd sliced my thumb. At first I could not find it, and soon I could not use it! Don't know if I cut it with the razor knife, or on the brake band, but one or the other.

Luckily my replacement seals from HL Supply came in yesterday, so the first thing I did today was replace the seal I had previously ruined.

I was determined to make the chain adjuster on this one work with the parts sent. I did, but not sure it was worth it. First, I had to grind in the case to get the big adjuster gear to fit. Then, it still did not work because the adjuster gear was too low. So I found a washer, and drilled the middle a bit larger, and now it works!!! But unless you got lots of time, you are likely better off just buying replacement parts from HL Supply.

The oil driver lever on this one cleared the case, but it is still a lot of work to get everything (clutch related) to fit. Again I fit the clutch drum first, then inserted the bearing, and I recommend this method to anyone building one of these.

I bring it out right before the Thunderstorms move it, and it pops on the 10th pull, then breaks the *$*#@* recoil cord on the next pull, and I got nothing but a handle in my hand! The cord broke about 1/2" from the handle (and then I remember that 440s have thinner recoil cords than 660s) s I just re tie a new knot about the handle. Based on this, I will be replacing all my 440 recoil ropes with Elastorstart cords. I prefer them anyway.

So then it still won't start and I check it, and the darn choke plate is stuck closed again. So I manually unstick it, and tune it a bit, and she seem to run well, and started oiling right away (unlike the first one, which was delayed oiling).

I throw a B+C on it, and it feels good. Need more run time, and some different woods, but I think she is good.

So then I take her apart, put her back together and take her apart to figure out why the *$%#* choke is sticking!!! That plastic piece that goes over the metal plate that holds the throttle rod is hitting the side of the choke lever and making it stick. I put Vasoline on it, and it stopped doing it, but I figured that is a temporary fix. So I thinned the plastic with a razor knife, than put Vasoline on it, and I think we are good to go.

 

[MustangMike]

FYI, I'll be Upstate and off the grid for the next couple of days.

 

[David Young]

I was after Stihl conrod sizes. Guess I should have said ..so. Doh..

You can be off by 5mm on the Conrod and it will Still be close. Just eyeball it with calipers or a mm ruler

More important is to use a ring pushed in by a piston to find the port numbers.

 

[MustangMike]

While Upstate on Mon + Tue, BB #2 did not make me happy. Problems with the choke, both not going on, then when it did go on sticking and then not releasing, and when I primed her and got it running, the idle went crazy and it sounded like it had an air leak.

So I take it out this morning, and I notice leaked fuel all over the back + right side of the tank holder. Upon further inspection, there was fuel leaking from where the fuel line goes into the tank, even though it was inserted. Well, they give you and extra line with each one of these kits, so I installed it.

Since I had it apart, I did some work to the carb. Specifically, I removed the choke plate and put a slight bevel on the inside to prevent it from sticking. I also filed the choke lever a bit where I think it was contacting the plastic carb cover, and a took the razor knife to the plastic carb cover again and thinned it a bit more.

I also took Randy's advice and did not make it quite as tight as I did previously.

The carb was very tricky to tune, very small adjustments to the Lo mix make a huge difference in idle speed, and she had to be set richer than I normally do (more than one turn out). The idle is not real smooth (kinda sounds like it has an aggressive cam), but it does not stall and she seemed to run pretty well. This one is definitely stronger than #1, but I'm hoping it gains a bit more with break in.

 

[huskyboy]

What kind of compression #’s do these things have?

 

[smokey7]

Do you think that the reason why #2 is stronger then #1 is due to the extra intake alone? Or do you think there is more causing the difference? I know the china coil on one of my jonny reds is about 10* further advanced then a oem coil. I am not sure if its the coils internal circuits or pole locations causing it. Other then having to be super careful following very specific starting process to avoid damage to you or the saw. It runs very good, and I am very happy with them but i bought a box of 10 coils on ebay for my 2 series huskys for stupid cheap like $5 each 1 bad out of the box. And timing is all over the place. I assume its the internal circuit's playing with the advance and retart curves. I think the coils could have as just as large of impact on performance as your extra intake timing on number 2.

 

[MustangMike]

I know there can be lots of other factors, but many "in the know" called that the intake was too high on jug # 1 for performance, and I think that is the largest difference.

What kind of compression #’s do these things have?

I'm using Caber rings, and it is very good. Jug # 1 has .030 squish, and it feels like pulling the Cross P+C 660s, and Jug # 2 has .018 squish and I find myself using the decomp button more often than not. I already broke the pull cord once by not using it.

For all the faults these jugs may have, the combustion chambers are beautiful, look just like a Mahle D jug!

 

[T.Roller]

I know there can be lots of other factors, but many "in the know" called that the intake was too high on jug # 1 for performance, and I think that is the largest difference.



I'm using Caber rings, and it is very good. Jug # 1 has .030 squish, and it feels like pulling the Cross P+C 660s, and Jug # 2 has .018 squish and I find myself using the decomp button more often than not. I already broke the pull cord once by not using it.

For all the faults these jugs may have, the combustion chambers are beautiful, look just like a Mahle D jug!

Bring it to top dead center then drop it. My decomp is plugged on my chinese saw. Timing advance hurts if you don't bring it up first.

 

[MustangMike]

The cord did not break when I was first starting to pull it. The saw had popped, and I gave it a good pull, and near the end of the pull the saw fired and I had a handle in my hand. Cord broke right at the handle (a knot and about 1" of rope).

I like how it runs, but it is my toughest saw to pull over.

 

[T.Roller]

The cord did not break when I was first starting to pull it. The saw had popped, and I gave it a good pull, and near the end of the pull the saw fired and I had a handle in my hand. Cord broke right at the handle (a knot and about 1" of rope).

I like how it runs, but it is my toughest saw to pull over.

That's when it'll happen. Top dead then drop start. Works

 

[smokey7]

Tdc and pull like you really mean it is the only way to start my baddest jonny 1 got with about 240 psi and no advance byond the extra that coil has. I went back to oem and a full key advance the saw still started easier but didnt have near the power or revs that the one china coil had. None of the other 8 good coils run like this one does.

 

[MustangMike]

STICKING CHOKE UPDATE

I tried to use the saw yesterday and learned that my mods to the plastic and the carb, and not tightening the nut so much did not resolve the problem.

I tried again to resolve it yesterday, but got so frustrated I did not even post about it. Luckily, today my next door neighbor stopped over and said "the plate is sticking on the bottom"!

If you close these chokes hard on these AM carbs, the choke just sticks shut. I had trimmed the top of the plate, but not the bottom. So, out the plate came, put a bolt through it and put it in the drill chuck and ran it against a file for a bit, and now it works!!! FINALLY!!!

Hope no one else goes through what I did to resolve this issue.

 

[MustangMike]

I had to go to HF the other day, and they had these Dremel style tools (corded) on sale for $9.99, so I couldn't resist. These tools are not for the pro, but if you just want to do a little here + there, they are not bad. It spins at 16,000 (kinda like a chainsaw)!. The biggest problem I have noted is it is difficult to install your cutter w/o wobble, and when you do get it straight, tighten the damn thing with some channel locks or it will not stay straight for long. Looking back, I should have just bought 2, one for a carbide tool and one for a diamond ball, cause switching cutters is a PITA. Also, as you use it, keep the pressure light, or your cutters will wobble right away.

Other than that, the tool is very small an nimble and seems to work well. The uppers in these Big Bore jugs end prematurely, so I figured I would kill 2 birds with one stone and install some bridge ports that would increase transfer flow and relocate the terminus of the upper at the same time.

I wish the "before" pic was clearer, but I don't think the after pic looks too bad considering this was my fist attempt with one of these things. (This is Big Bore jug #3). If this helps performance, the other jugs will just have to come off!!! I used a carbide cutter first, then a diamond ball.

 

[MG porting]

Timing #s

OK, here are the timing #s I came up with (all w/o base gasket):

First the New West Big Bore:

Sqish .030 Ex 103.5 Tr 122 In 64

Now the Huztl 440:

Squish .058 Ex 101.5 Tr 124 In 71.5

I'm disappointed with the Squish # on the 440 and the Intake # on the Big Bore.

Being as the Big Bore cylinder has a very tight combustion chamber, I can live with the .030 squish, but I think I need to try my hand at grinding and lower that intake to the mid 70s, then it should be good to go.

Thoughts/Comments both welcome and appreciated. I've never grinded on a jug before, but I think I can get to the intake with my Electric Sharpener with the Diamond Stone. By comparing it with my D jug, I know about where to bring it.

I think your on the right track I just did the opposite on a farmertec ms660 cylinder I had to raise the intake on it but that's about the norm.

 

[T.Roller]

I had to go to HF the other day, and they had these Dremel style tools (corded) on sale for $9.99, so I couldn't resist. These tools are not for the pro, but if you just want to do a little here + there, they are not bad. It spins at 16,000 (kinda like a chainsaw)!. The biggest problem I have noted is it is difficult to install your cutter w/o wobble, and when you do get it straight, tighten the damn thing with some channel locks or it will not stay straight for long. Looking back, I should have just bought 2, one for a carbide tool and one for a diamond ball, cause switching cutters is a PITA. Also, as you use it, keep the pressure light, or your cutters will wobble right away.

Other than that, the tool is very small an nimble and seems to work well. The uppers in these Big Bore jugs end prematurely, so I figured I would kill 2 birds with one stone and install some bridge ports that would increase transfer flow and relocate the terminus of the upper at the same time.

I wish the "before" pic was clearer, but I don't think the after pic looks too bad considering this was my fist attempt with one of these things. (This is Big Bore jug #3). If this helps performance, the other jugs will just have to come off!!! I used a carbide cutter first, then a diamond ball.

Pick that cylinder up and hold it while your grinding. You scared of it?

 

[MustangMike]

Yea, like I don't have enough trouble getting it to cut where I want as it is!