375xp-51.4mm

[parrisw]

Got the squish machined today, ground out the lower transfers and machined the base. Now to bolt it on the saw and check numbers.

 

[Rudolf73]

Welcome back Will! :biggrin:

I has some clearance issues with the xpw cylinder and flywheel after cutting the base, but see how you go with yours.

 

[komatsuvarna]

Not sure that helps much, as the venturi is basically the same?

Yes the venturi is basically the same. Even the HD12 that comes on the 372 has a big venturi compared to the other saws in it's class, even bigger than 7900 as well.


Nice work as always Will!!

 

[wigglesworth]

I've heard the swap really helps, so I will try.

Not sure on the bore sizes.

An HS 296 can be opened up to just shy of 19mm and still keep a good relationship of throttle bore to Venturi size. Expect to do some drilling if you go that far though. It's a swap that's well worth it....

 

[parrisw]

Welcome back Will! :biggrin:

I has some clearance issues with the xpw cylinder and flywheel after cutting the base, but see how you go with yours.

Yes the venturi is basically the same. Even the HD12 that comes on the 372 has a big venturi compared to the other saws in it's class, even bigger than 7900 as well.


Nice work as always Will!!

Thanks for the welcome back guys, good to be back at it, was actually nice to take a break.

 

[parrisw]

An HS 296 can be opened up to just shy of 19mm and still keep a good relationship of throttle bore to Venturi size. Expect to do some drilling if you go that far though. It's a swap that's well worth it....

Are you opening just the Venturi? I was thinking of opening another 1mm. How much did you have to drill?

 

[parrisw]

So I need a 390 intake? And XT filter adapter?

 

[duramax99]

372 intake. Just trim the wing where the pulse hose goes through and clock it so the carb sits flat. Xt372 adaptor and choke lever will let you use the stock 372 filter

 

[parrisw]

372 intake. Just trim the wing where the pulse hose goes through and clock it so the carb sits flat. Xt372 adapter and choke lever will let you use the stock 372 filter

Ahh, ok, I'll have to go pick up those two parts then. Thanks.

 

[duramax99]

Can use the 390 filter adaptor just cut the choke wing off of it. Youll have to use a 390hd air filter and trim the ribbing on the inside of the 372hd filter cover but it does all fit under there!

 

[duramax99]

View attachment 295283 built this beast over winter now im building a matching BB372 with a 390 carb swap.

 

[parrisw]

Can use the 390 filter adaptor just cut the choke wing off of it. Youll have to use a 390hd air filter and trim the ribbing on the inside of the 372hd filter cover but it does all fit under there!

Ok, I'll give that a try first, since I have those parts. What about choke pull? Do I still need the XT one?

View attachment 295283 built this beast over winter now im building a matching BB372 with a 390 carb swap.

Sweet.

 

[duramax99]

Ive just been using a 372 choke lever if i remember right. Might have been the 390 lever but either way you dont need the 372xt lever

 

[parrisw]

Ive just been using a 372 choke lever if i remember right. Might have been the 390 lever but either way you dont need the 372xt lever

Thanks. I'm sure when I do it, I'll figure it out, can't be too hard.

 

[duramax99]

Its not too bad at all. Just remember to trim all the ribbing out of the air filter cover or it can be a real pain to get off later! Dont ask how i know that lol

 

[parrisw]

Its not too bad at all. Just remember to trim all the ribbing out of the air filter cover or it can be a real pain to get off later! Dont ask how i know that lol

Yep. The bigger filter can't be a bad thing either.

 

[Jacob J.]

Yep. The bigger filter can't be a bad thing either.

I can send you an XT manifold and choke lever in your next box- I have an extra set.

 

[parrisw]

I can send you an XT manifold and choke lever in your next box- I have an extra set.

Well, that would be awesome! Then I don't have to do any trimming of the filter cover.

You should be receiving a nice box soon too!

 

[Jacob J.]

Well, that would be awesome! Then I don't have to do any trimming of the filter cover.

You should be receiving a nice box soon too!

No worries- I'd like to see you get the most out of this, so's I can get the most out of mine later...

 

[parrisw]

No worries- I'd like to see you get the most out of this, so's I can get the most out of mine later...

YEA Buddy! Now your talking!