First 372xp Builds

[ken morgan]

I don't know if the 064 piston will work in the 372 bb or not. The 268 bore is 50mm not 52mm. The step opens up the exhaust without actually lowering the port at the cylinder wall.

Having only experience at porting rotary engines and none with two strokes I should probably not comment, but here goes.

Any time a gas expands, its temperature drops, as its temperature drops it also slows down causing turbulence. this is not desirable. anything larger than what the port can flow will result in a drop in temp, and a drop in velocity.

we have the exact same issue when porting the exhaust of a rotary engine as the port itself is an ovalish/rentangular shape and is smaller than the runner that leads through the casting and into the exhaust header it has a lip all around the port similar to which you created.

That being said if the lip you created creates a low pressure scavenging wave to form in some fashion than what i just typed is a mute point.

Thoughts?

 

[Evan]

Ive seen were guys use epoxy to putt timming were they want . I see no use other than that.

Im a hack porter i dont know much if any of the science these guys are doing inside these things

 

[stinkbait]

Finally got it together. I used a 390xp intake boot, x torq carb, x torq filter and elbow, and x torq choke lever. I may have went a little overboard on the pipe for the muffler. The pipe is actually bigger than the opening. I was afraid to open it up to fit the pipe. Hopefully I can run it tomorrow.

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[ken morgan]

Finally got it together. I used a 390xp intake boot, x torq carb, x torq filter and elbow, and x torq choke lever. I may have went a little overboard on the pipe for the muffler. The pipe is actually bigger than the opening. I was afraid to open it up to fit the pipe. Hopefully I can run it tomorrow. View attachment 650130View attachment 650131View attachment 650132View attachment 650133

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Work that hooker like a thai whore on dollar day with the 3rd MarDiv in port!

 

[Evan]

Looking niccccccce what size is exhaust port

 

[stinkbait]

Looking niccccccce what size is exhaust port

The pipe is 1" I believe, but I cut the outlet in the muffler smaller. I fired it up briefly and she's a loud one.

 

[Evan]

Looks bigger. I run 1" on 70cc saws with spark screen and 3/4 on smaller saws.

 

[AlfA01]

I recently got a junk 365xp parts saw and a huztl 372xp parts kit. I ordered a big bore kit at the same time as the parts kit for around $12. I was very surprised at how good the big bore cylinder looks. I plan to put the bb cylinder on the just saw and the 50mm cylinder on the 365xp with a 268xp piston with a popup turned. I put the huztl crankcase together and fitted the bb cylinder. With the base gasket my squish measured 0.055". I turned the base of the cylinder down 0.035". This put my intake at 77. I set my exhaust at 100 and my transfers at 120. Still have to changed my ports. I also plan to run a x torq carb and filter with a 390xp intake boot on the huztl saw. View attachment 649682View attachment 649683View attachment 649684View attachment 649685

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That intake port looks pretty wide. What piston did you run and how wide was the skirt? I'm doing a J'Red 2171 (372) build now and I'm curious which route to go with on my cylinder.

 

[AlfA01]

Randy aka mastermind aka moobs ake chicken legs is probably in the top 3 professional builder/porters knowen around here. Very smart guy with a thriving business and a very great guy. If he says something dont discount it hear what he has to say think it through and do what you want. Just kbow he says something for goid reason with many years experience to back it up. That man does several hundred saws per year and is booked many months out.

I once heard him called "emu legs". Lol. I ordered one of his pieces of work. Can't wait to get it. Nice guy and really helpful.

 

[stinkbait]

That intake port looks pretty wide. What piston did you run and how wide was the skirt? I'm doing a J'Red 2171 (372) build now and I'm curious which route to go with on my cylinder.

It's the one included with the bb kit. I only went 65% of the bore on port width. I've read of people going 70%.

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[SierraMtns]

Any updates on this saw? You still running it?

 

[stinkbait]

Tue saw runs awesome. After some run time it was only blowing 160psi so I ordered a meteor 272 piston. Cut a popup on it and it bumped the compression up to 185psi. I only have about 3 tanks through it. Loaned it to a friend over a month ago and he could never get it cranked. He brought it back and I started it on the 3rd pull. Sent it back with him and he pulled the rope out trying to get it to crank it. It's been sitting in my garage floor ever since then. Got to put the rope back in it. I've been running the piss out of my huztl 660 lately. I'm very impressed with it. Didnt do any port work to it at all. I put a hyway pop up piston in it and opened up the muffler. Still has the base gasket. I've been running a 28" bar and 8 tooth sprocket on it. I need.to make videos of both saws.

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[Czed]

Tue saw runs awesome. After some run time it was only blowing 160psi so I ordered a meteor 272 piston. Cut a popup on it and it bumped the compression up to 185psi. I only have about 3 tanks through it. Loaned it to a friend over a month ago and he could never get it cranked. He brought it back and I started it on the 3rd pull. Sent it back with him and he pulled the rope out trying to get it to crank it. It's been sitting in my garage floor ever since then. Got to put the rope back in it. I've been running the piss out of my huztl 660 lately. I'm very impressed with it. Didnt do any port work to it at all. I put a hyway pop up piston in it and opened up the muffler. Still has the base gasket. I've been running a 28" bar and 8 tooth sprocket on it. I need.to make videos of both saws.

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I kept breaking ropes on my high comp saws
So i switched to true blue rope
4.5 year's ago
Haven't broke one yet

 

[Yotaismygame]

Finally got it together. I used a 390xp intake boot, x torq carb, x torq filter and elbow, and x torq choke lever.

Did you find the 390 boot was a good deal bigger than the 372 intake inlet? I just bolted a xt carb on my 372xp with the same setup as you but initially I had the 390 clamp on there but it was too big even tightened all the way down. I switched to the 372 clamp and now I'm wondering if I have a leak coming from that spot. Going to pressure test it tonight.

 

[Westboastfaller]

'American' will put a kickstand on a saw.
God Bless

 

[stinkbait]

Did you find the 390 boot was a good deal bigger than the 372 intake inlet? I just bolted a xt carb on my 372xp with the same setup as you but initially I had the 390 clamp on there but it was too big even tightened all the way down. I switched to the 372 clamp and now I'm wondering if I have a leak coming from that spot. Going to pressure test it tonight.

I dont remember which clamp I used but I was able to get the boot tight enough.

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[Yotaismygame]

Need the 372 clamp. No issues with using that. I also used a xp cable holder with zeroes issues. Actually that was with a xp boot also. I’ve done both 390 setup and xp setup both work