Farmertec 372XP Build

That's sure something. Nothing like learning to build a saw and look for engineering/manufacturing defects at the same time. I think id need to work on my patients a little more before attempting to build one of those. They looked like a cool idea when i first saw em. Like a 3d puzzle but looks like you gotta make/shape the peices to fit.

The way i understand it, caber rings can't be beat. I have them in at least one saw of mine but no experience on longevity. Iirr i didn't have to file ring end gap into spec though.

 

If they are installed correctly they won't come out...the gap needs to be at the top or bottom, if the gap is to the side the "sudden stop" and reversal of direction at the top and bottom of the stroke can compress the clips enough to come out...even if using clips with no "leg" I still position this way...just engine building 101, have never had one come out either.

 

You can just run the top ring if you wish.

 

Thanks for the tip. That make sense because I noticed the OEM cir clips had the ear on them. Will definitely make sure mine are correct.

As my dad says “the blind lead the blind” is what I feel like when watching some of these videos on YouTube. Think a lot of these folks aren’t experts and they just regurgitate what they saw on another video or are more concerned about “building their channel”. Some do a good job though. Watched a couple videos when I first got my saw and I knew what I they were doing was wrong and I hadn’t even built a saw yet.

I tell people I’m at expert at nothing, not even breathing air.

 

Ordered the Caber rings on Sunday after seeing what the Stihl 440 rings were going for on eBay. I forgot that there's the prices they should be, and then there's the Stihl price.

Noticed that the Hyloman Blue on the case, and on the cylinder is starting to dry up a little. Should I scrape that off and re-apply new when I'm ready to put it together ?

 

Caber rings are fantastic. This is a good series of saws to mess around with. Walt (afleetcommand) has a decent channel with a few dozen videos dedicated to 371/372s.
I have built up three or four of ‘em. Not the China copies as I can’t deal with the issues on critical parts (bearings, case bearing pocket, piston, rings, circlips, coils, and cylinder plating). Been there, done that.
Most other AM parts are actually decent.

Like the 660s, the OEM design is what most guys building these should realize; the copies are neat because the originals were awesome.

 

Got the Caber rings a few days ago. The cylinder definitely goes on a lot easier since both of them are round.

When I vacuum tested the saw after putting the cylinder on I got nothing. Thought the issue might have been the Hylomar base gasket since I had to pull the cylinder back off again to get the carb boot and pulse line put on. Pulled the cylinder fully off and scraped all of the Hylomar off and used the paper base gasket. Still get nothing in my vacuum test. Took the decompression valve off and plugged it my finger, nothing. I have the exhaust and intake plugged with some pieces of rubber and I have my pump hooked up to the pulse line.

Read a few posts on Facebook and I guess the rubber boot on the carb on these saws will sometimes crack. Thinking about starting it and spraying starter fluid around clutch, cylinder, and carb boot to see if I can figure the problem out. Anybody see any issues with that ? It seem to have really good compression, it would definitely be a work out to try to start it without the decompression valve.

 

How are you plugging the intake and exhaust off?

 

Cut some pieces of rubber. Sandwiching one piece of rubber between the carb and the carb boot ( picture above ) with the bolts tight. Same thing for the exhaust.

 

Oh, ok...does that test pump have a pressure mode too? Just curious if it'll hold pressure...and if not then that might can be found with some soapy water...

 

Is the clutch tightened with the spacer intact?

 

If nothing obvious, I would question how effectively you’re blocking things. A leak is normally slow and steady unless something is way off.
Don’t start it yet. Perfect your setup and rule out leaks that will cause you tuning issues later. The brake cleaner test is ok, but often gets sucked around the air filter and makes ruling out leaks tricky.

 

Avoid starting fluid or carb cleaner. Brake kleen, wd-40, or other aersols are better.
^this is for the mentioned leak check, not to get a saw running. Use mix for that.

 

I'd spray it down with some water and a few drops of dawn and try to see where it's bubbling before going any further.
If it's leaking that badly it will show itself quickly.

Ernie

 

Yep spacer and small o ring are in place.

 

That’s what I was thinking too since I can build zero pressure. There’s something wrong with how I’m doing it. I’ll take some pictures and post them.

 

Take that vacuum pump off and blow on the line...see if it seems like it's holding...you don't need a ton of pressure...you could try that in suck mode too

 

Ok, good. With the clutch tightened?
Leaks-
Impulse line, base gasket, case gasket, fuel line/carb (which you are bypassing), intake, spark plug, decomp valve, seals. Other than casting flaws or a screw hole in the crankcase not filled (oiler, should have sealant around it), there’s really not many other places that could leak any air.

 

Right… try pressure.

 

Hmm...decomp valve pushed inadvertently?