Farmertec 372XP Build

Want to preface this thread with saying that I normally do NOT knowingly buy stuff from China. These kits are only available from a Chinese company, and I feel that the learning experience out weighs my disdain for supporting a country that treats their citizens like garbage. Soap box over with......

Over the holidays I came across a post or a thread somewhere about Farmertec having an end of the year sale. I know a few years ago a lot of folks were building these kits but I don't hear much about them anymore. Based off of some of the recent build videos on YouTube they seem to have upped their quality over the years.

During the winter I normally cut wood for a few hours here and there during the weekends. With El Niño in full effect all it does is rain anymore. I'm not too big on going out wasting money on worthless "stuff" ( shopping ) and I can't sit still very long so I thought that this build would be a good way to consume some of my time during the winter. I've never messed around with gas engines other than doing basic maintenance on them.

There are some folks on here who work on chainsaws for a living and others that do it as a hobby. My thought behind this thread is that you guys could help me dispel some of the BS that I read on the Facebook group for these saws and maybe point me in the right direction. I've probably watched half a dozen YouTube video on how to build this saw and everyone has their own way and it's the right way.

I don't normally get into a lot of "big wood" on my property but there are some larger trees that have recently fallen down that I'd like to get cut up. I'll probably use this <10 hours a year, and if it breaks it's not a big deal since I have a pretty new 60CC saw that I could probably use instead.

Based off of what I've read you can delete the base gasket and trim the skirt on the cylinder without having to change the timing ( definitely outside of my knowledge area at this point in time ) ?

I've come up with a list of supplies, and some notes next to them. Does anybody see any issue with this list ?

Supplies Need

• Blue loctite - bolts
• Loctite 518 ( base gasket delete ) - is there something better ?
• Motoseal, yamabond, or threebond ( case gasket along with the paper gasket )

 

Excellent! Another build thread.

I use Hylomar Blue for my sealant. Learned of it a few years ago from Joe Harkness aka Dyno Joe. Works excellent so far and its easy to remove as it stays more like a toilet wax ring consistency once set up. It also reseals itself if there ever is a momentary separation of the mating surfaces. I know others use Dirko, motoseal, Yama bond ect. It just needs to be fuel and oil resistant / proof.

 

Thread set to watched! Nothing wrong with learning new things. This should be an interesting project for the winter.

 

Obviously lots to talk about in your post but I'll start with this list. First thought reading thru and not using a paper gasket come to mind.

Quick story: Was working on my dirt bike engine a couple months ago. Reassembling and i didn't have a new paper gasket for the starter bendix. Not a typical bendix, this one takes the output of the starter and turns in 90°. So there are a couple gears behind a cover where this gasket, that i didn't have, goes. Anyway i was just going to use some rtv in place of the paper gasket. Got it all together and the starter would engage but turn really slow like it had a huge load on it. Well come to find out a paper gasket is needed under the starter bendix cover in order to maintain proper clearance for the gears.

So just pay attention while assembling anything "not by the book". I assume they come with an instruction book? Is it all pictures and symbols?

I use permatex moto seal for any sealing surfaces that come in contact with fuel. Also be careful when applying whatever sealant you choose to use in place of the base gasket. Doesn't take much to squish out alot and that squish out is usually right in the path of the transfer ports.

 

Important points Jeffrey .

Squish clearance needs checked without the gasket to see if there is enough space between the piston and squish band area. If there are cylinder extensions, that hang below the cylinder base, and protrude into the crankcase, you need to make sure they don't bottom out in the crankcase without the gasket.

The Hylomar sealant is the only one I've seen that cleans out of any ports from running yet stays sealed in between the clamped parts. It's a very cool product. It doesn't permanently protrude into a port if used to heavily like any of the others.

 

My boys and I have "built" a half dozen farmertec kit saws, 372, 660, & 366, they usually go together well, and have all started up and made sawdust kinda like real ones.

They do not come with instructions at all... we just looked up a few ipl's online to figure out the stihls, the 372s are pretty much self explanatory.

Usually takes about 2-3 hours to put one together.

 

They come with nothing, it's just a big box of parts. There are however some folks that have been kind enough to go through every bolt and create a parts list and publish it. I like the idea of going through every bag, and then putting them in their own separate bag and labeling them but that seems a little time consuming. Someone posted the Husqvarna parts manual for the saw on the Farmertec Facebook group, that should help also.

 

Any tips you can give ? Did you also clean up the skirts on the cylinder similar to the attached pic ?

From what I've read / heard there's around .050 of squish with the base gasket is .020 so by removing the base gasket that gets you down to about .030 of squish which most folks say makes the saw run much better. I've seen on videos on how to check squish. Is there a way to check and see if the piston is going to hit the crankcase ?

 

We just built em as they were.
Some with base gasket and some without.

 

It won't be the piston that is the potential issue, its these...

They have the potential of bottoming out in the crankcase without the gasket. You can make measurements with the depth side of a pair of calipers to verify.

 

Notice a performance difference on the saw(s) that don't have the base gasket ?

 

Put the cylinder jug on the bottom end dry. Reach thru the spark plug hole with thick electrical solder and rotate crank to squish the solder. Measure solder for squish clearance.

 

They are more painful to start.

We just made a few cuts to make sure they worked then dropped em off at an auction.

Basically it was just a learning experience for the boys.
It's kinda like doing a jigsaw puzzle but more practical.

 

I should have read your post much closer. Pictures are worth a thousand words. Thanks for the picture, that makes sense now.

 

That's the interesting part. Trying to figure out exactly what people are trying to say and then make that happen with your hands. It's almost like magic sometimes.

 

I built one a few years ago after I built the 660 kit. Husqvarna is a simpler design and was much easier. My squish was around .060 with gasket and .035 without. I used motoseal on cylinder and case gasket. I have since used hylomar blue on a couple saws with good results. Seperating the bolts is a good idea. Check the crank bearings for metal shavings. Take your time and enjoy the build. Put the intake boot on the cylinder before you bolt it down, won't go on otherwise. I made that mistake. The rubber O ring that goes on the clutch side crank used to be missing from all the kits, don't know if they include it now or not. Mine runs very good with gasket delete, muff mod and I think I did a small timing advance as well.

 

Yes, and I watched a YouTube video the other day and the guy ordered an aftermarket piston and the skirt was different on the side it was hitting the crank ( if I remember correctly ). He ended up having to change the cylinder, and crank too. Of course I can't find the video after doing some searching. That came to my mind when I read the post too.

 

Check your bolts first...some kits come with loctite already on the bolts.

Gasket thickness used as part of the spacing is VERY common on motorcycle/ATV engines.

On my 660 kit the piston skirt actually lightly contacted the crank at BDC.

Good advice...check inventory first, organization is always good!
As far as bearings, I always spin them by hand and see if they feel smooth...some of these kits are known for junk bearings in some applications (wrist pin in the earlier 660 kits) and I always lightly oil or grease bearings and/or appropriate moving parts during assembly...might run a little "slobbery" on start up (and smoke a lil extra at first) but it can't hurt.

 

That's an interesting one. Seems like it would've been easier to get the correct piston or at the least trim/clearance the skirt of the new piston. Some people shouldn't be allowed to upload content on youtube.