365-372 build

[SkippyKtm]

Here's what I am looking at.

The dark ring varies in height. In one spot, the shiny plating goes almost to the top of the bore.

In another spot, the dark ring extends down what appears to be 1/4".

The height variation of the dark ring cannot be explained by honing. If the hone stopped short of the top, then the affected area would be a consistent height.

An inspection mirror helps, but it's still not the same as looking at the area directly. That requires either a borescope, or sawing the jug in half.

The dark ring appears to extend down far enough to be swept by the rings. If the dark ring is indeed unplated, then it'll still run, but there will be questions about ring sealing and longevity.

Here's one of the jugs that I sawed in half. Before sawing, I could only see a mysterious dark ring near the top of the bore, and I could see that the ring varied in height, similar to your mysterious dark ring. After sawing, it was clear that the ring was partly due to a huge gouge. The variation in height was due to missing plating, not missing honing. My guess is that this area is "sunken" due to a casting defect.

The grey stuff is bare aluminum. There are no honing marks, because there is no plating. In any event, this is not conducive to sealing the rings.

I am not familiar with the plating process, but apparently any spot that is greater than bore diameter does not receive plating. For example, if there is a gouge, the gouge does not get plated. If the casting has "sunken" and pulled away from the bore, the "sunken" spots don't get plated. The area around the decomp hole often seems to be missing plating, perhaps because that spot is a little "sunken."

I'd love to hear someone who knows more about the plating of chainsaw jugs -- hint, hint, Timberwolf, if you are reading this -- explain what kind of things go wrong that cause the plating to be screwed up at the top of a jug.

Great post, You've got me wondering how the plating process is done, and how these lower areas could be missed like that.

 

[SawTroll]

Don't be so quick to throw that carb away! I built my 372 from a 365 and I use the zama carb with no ill effects.

From what I have heard it really is about carb size, not about Walbro vs. Zama as such......

 

[parrisw]

What I've noticed is when you port these aftermarket cyl's for instance, the process has traveled into the port and is more difficult to penetrate than bare aluminum. It is obvious to the naked eye that the process has gone beyond the cyl surface itself.

Thanks Al, Ive actually noticed that a little bit in OEM kits.

 

[Winn R]

Parris -- my thanks to you. The carb you sent is now in an up and running saw!

 

[parrisw]

Parris -- my thanks to you. The carb you sent is now in an up and running saw!

Great!! Good to hear.

Will

 

[PB]

You got the p&c from MCW, do you know what brand it was? Is it different than the Bailey's kits?

PS: Thanks for sharing, I never get tired of build threads.

 

[parrisw]

You got the p&c from MCW, do you know what brand it was? Is it different than the Bailey's kits?

PS: Thanks for sharing, I never get tired of build threads.

Sorry I don't know the brand or if its the same as baileys or not, this is the first BB kit I've done.

 

[PB]

Sorry I don't know the brand or if its the same as baileys or not, this is the first BB kit I've done.

Thanks. I Just like to know if there are options out this if ever need be.

 

[AUSSIE1]

You got the p&c from MCW, do you know what brand it was? Is it different than the Bailey's kits?

PS: Thanks for sharing, I never get tired of build threads.

Sorry I don't know the brand or if its the same as baileys or not, this is the first BB kit I've done.

They are a generic brand, different to what Bailey's sell I believe...

 

[wendell]

They are not Bailey's brand.

 

[Saw Dr.]

Another great thread. Where are you as far as collecting the missing parts?

 

[parrisw]

Another great thread. Where are you as far as collecting the missing parts?

Pretty much got them all now or on the way. Waiting on a order from Baileys next week, then all I need is an intake boot, I just noticed last night it is split, I never noticed it before since the split was under the little round white plastic mount, I wish I knew then I would of got it in the Baileys order, and none of my local dealers have them.

 

[2stroked2smoke]

Are you gonna put the 372 air intake and airfilter system on this saw? I did on my 365 to 372 conversion and it seemed to help .

 

[hamish]

Are you gonna put the 372 air intake and airfilter system on this saw? I did on my 365 to 372 conversion and it seemed to help .

FYI the air intake and air filter are the same for bothe the 365 and 372, be it high or low top versions.

 

[2stroked2smoke]

FYI the air intake and air filter are the same for bothe the 365 and 372, be it high or low top versions.

I own both and they are not the same. The 365 has a flat clip on airfilter and the high top 372 has a round filter with a thumb screw that holds it on FYI. It takes a differant intake to use the bigger airfilter of the 372

 

[Jacob J.]

I own both and they are not the same. The 365 has a flat clip on airfilter and the high top 372 has a round filter with a thumb screw that holds it on FYI. It takes a differant intake to use the bigger airfilter of the 372

I think what he meant is that both air filter systems and manifolds will fit either the 365 or the 372. I've owned around 11 365s and 372s and have had both air filter systems and manifolds on either model.

 

[parrisw]

Are you gonna put the 372 air intake and airfilter system on this saw? I did on my 365 to 372 conversion and it seemed to help .

i take it you mean the high top system. Some 372's actually come with the low setup FYI, just like the other guys said.

At this point no I'm not putting it on, I'm just getting this going low buck right now, its a test bed for different piston cylinders, porting options, just something to play with right now, I'd like a high top for it and my 371, just cost a few bucks to get the parts.

 

[SawTroll]

FYI the air intake and air filter are the same for bothe the 365 and 372, be it high or low top versions.

I think what he meant is that both air filter systems and manifolds will fit either the 365 or the 372. I've owned around 11 365s and 372s and have had both air filter systems and manifolds on either model.

Right, they both come with the low-top here, but some 365s had "solid" top covers, without the clip-off filter cover.

The fact that most 372s come with the high top is an importer/distributer "thing", and not a factory one!

 

[2stroked2smoke]

Right, I get it . I should have called it a high top instead of a 372 setup and a low top instead of a 365 setup. Gotcha, my mistake.

 

[Kwdog75]

So if i built a 372 "low top" it would be correct?