It's tygon. No timed cuts. All I have to do though is compare it to Mikes. Mine was just a hair behind it before.
Want a bigger carb for your hopped up 372/375?
- Thread starter TK
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komatsuvarna
Arboristsite MVP
Good thang you put that bigger carb on Brad, your gonna need it come next Saturday!:jester:
nmurph
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Brad, what do you think of this swap? Pro's/Con's??? I have a spare 385 carb on the shelf with a new kit in it.
Well, the one I put on my saw is bored out to 0.74x", almost 3/4". I don't have much time on it since the swap, but it runs very well. It won it's class at Wiggs last GTG
Bump for anyone looking to put the XTorq carb on your 372XP. Everything would be the same exact use the 372 XTorq carb.
idiotwithasaw
another row to hoe
Here's mine with an xtorq carb and an xpw top end. This is kinda just roughed in. I'm gonna get the diverter out and clean up some rough spots. But it starts and idles good, and revs up good. Gotta get it in some wood soon.
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idiotwithasaw
another row to hoe
For those wanting to know how I did this conversion. I used a boot off an original 372 and turned it till it lined up with the xtorq carb and the carb was setting level. I then trimmed the rubber that the impulse line went through so the cover would fit correctly. For the filter base I used one from a 372 xtorq high top so I could use the bigger filter.
I had to trim a 1/16 of an inch or so off of the plastic shielding from the throttle cable as because of the awkward position it wasn't allowing the throttle to go back to idle, I'm not sure if using the intake flange from a 390 would have solved this. But it seems to work fine and there is no additional slack. I figured cables were cheap and I have extra, So might as well try it.
If you want to do this it's super simple and can be done in less than an hour. Takes longer to get everything together than it takes to actually install everything. Probably quicker if you are smarter than me and do it before you install the cylinder. If I do this again I will put the carb and boot together then put it on the cylinder and turn it till the carb is level with the cylinder and tighten it down. Good luck, and happy modding, hope this was helpful.
I had to trim a 1/16 of an inch or so off of the plastic shielding from the throttle cable as because of the awkward position it wasn't allowing the throttle to go back to idle, I'm not sure if using the intake flange from a 390 would have solved this. But it seems to work fine and there is no additional slack. I figured cables were cheap and I have extra, So might as well try it.
If you want to do this it's super simple and can be done in less than an hour. Takes longer to get everything together than it takes to actually install everything. Probably quicker if you are smarter than me and do it before you install the cylinder. If I do this again I will put the carb and boot together then put it on the cylinder and turn it till the carb is level with the cylinder and tighten it down. Good luck, and happy modding, hope this was helpful.
wildman ben
ArboristSite Member
@idiotwithasaw so how do you find this mod vs stock?
so in theory If I have an xtorq 372 I could switch the top end to a 51.4mm XPW by just switching out the P&C and intake boot yea? or even just delete the dividers in the intake boot perhaps.
but then I've heard the top cover is different, it sits higher or something like that effecting the way the engine cools down causing over heating in warm weather.
and so how would one get around that, unless the original XP top cover and chain brake swap over
so in theory If I have an xtorq 372 I could switch the top end to a 51.4mm XPW by just switching out the P&C and intake boot yea? or even just delete the dividers in the intake boot perhaps.
but then I've heard the top cover is different, it sits higher or something like that effecting the way the engine cools down causing over heating in warm weather.
and so how would one get around that, unless the original XP top cover and chain brake swap over
roy wilson
ArboristSite Lurker
i,m planning doing the 385/390 carb install on a 372 as its got the 52mm BB on it with the 272 pop up piston machined 40thou x10mm in to assist transfer timing as its 40 thou taller than 372 piston and single ring and 20g lighter and base gasket delete and bit of woods porting too ,open muffler so its going to be a ripper , i saw the last post saying to install the 372 Xt carb etc , is it bigger ? i have one of those but not studied it yet ,i do have a 385 also so would temporarily swap both over to the 372 so see how it does but will prefer the 385/390 carb swap , anyone on here have a spare used carb ? to sell to me reasonably as they are real expensive over in uk , so dont really want to spend too much on it as it runs well now but want to do one more mod
Yes, considerably so.
Wow what a great vintage thread....multiple builders from back in the day and no arguments
SawTroll
Information Collector
Surely, as I recall it no 385/390 carb has a larger venturi than 17.5 mm (same as the HD-12), while the XT carb is 19.05 or so mm.
Chainsaw Jim
CJ Saws, LLC
The xt carb (rwj4) needs a few mods to run properly without the divider. It might be best to use the 385/390 carb to start out with.
roy wilson
ArboristSite Lurker
thanks guys , need to get one from someone on here as they are real expensive i UK i do have one on my 385 , so might say fook it , i,m goin to see how she runs 
What kind of problems? I've noticed no trouble either with or without the divider.
Chainsaw Jim
CJ Saws, LLC
It's strange you'd say that because I know of at least a handful of times in the past where you yourself mentioned how it effected performance and suggested leaving the divider in place.
I think you're confused with the MS261C.
Chainsaw Jim
CJ Saws, LLC
The only thing I'm confused about is why you'd have conflicting opinions.
