Farmertech 372xp wont hold a tune

[TRTermite]

I have sorta tried pulling on that vent hose thinking the same thing before I bought the second tank, but your right now that i dont absolutely NEED that tank i could try it and if I screw it up in the name of science and helping others then so be it. Matthew Olsen on youtube I think does something with them tank vents but I'm not sure if it's the same style or not I dont think his video showed him removing it.

Keep us (The curious) posted.

 

[Alanmurphy6912]

Yep Termite. The way I see it, the tank has to release pressure that builds up in the tank from fuel sloshing around. Also has to allow air into the tank as the diaphragm draws fuel and creates a suction.

He ought to try running the saw with no vent tube, duck bill, grub screw, of any kind... just an open hole. Simply run the saw, and hold the saw upright and don't do any dramatic cutting maneuver's. See how it behaves.
.

The vent that is in the "new" tank I have on it now is like one of them gold colored mesh looking vents that I dont think are removable or I would try this. Only other option is keep the cap cracked the entire time

 

[TRTermite]

That is the way I understood it for a long time,but I've got a few other saws that hiss when opening the cap so I'm not sure

That would be the pressure due to the needle not reaching its' pop off setting.. I could be wrong.

 

[Alanmurphy6912]

Keep us (The curious) posted.

Yes sir I will. I really appreciate everyone's kindness and help here on this forum. I hate reading forums and then noone ever updates the post with what the issue was and or what solved the problem. I will be sure to update as I've been keeping up daily with yall on here. Thanks again.

 

[TRTermite]

The vent that is in the "new" tank I have on it now is like one of them gold colored mesh looking vents that I dont think are removable or I would try this. Only other option is keep the cap cracked the entire time

I have done a few on Jonsereds I think the old ones were green and new ones black (Or the other way around) but you will be luck to remove one and it still be reusable I put a screw in the old version to get it out I was told by a long time owner of a Husky shop the old ones would plug with very small fines and really mess with your head. He was right and the new ones were worth it. In simple words leave your good one alone (IMHO) but get some stress relief on the other one. IF Possible Avoid the
"Run over it with the TRACTOR" procedure.

 

[TRTermite]

I was surprised how hard an OEM tank vent pulled to remove it. I wouldn't have tried so much if I hadn't had the reassurance of someone in the know. I wouldn't doubt that the hose separates and you have to extract the rest with a screw or something look up a pic of the OEM vents to see how they look and snap fit into the case or do the UTube thing to get an idea of what you are getting into/

 

[Bob Hedgecutter]

Yes sir I will. I really appreciate everyone's kindness and help here on this forum. I hate reading forums and then noone ever updates the post with what the issue was and or what solved the problem. I will be sure to update as I've been keeping up daily with yall on here. Thanks again.

Now be fair, sometimes there is never enough information shared or rather the correct kind of information shared for responders to guess the correct diagnosis.
Then factor in the fact you are asking about a family of "saws" some people dislike the very notion of and thus decide to skip over the posts rather than reply- and a lot of those folk are very good servicers of chainsaws!
Copycat saws are fine for anyone that wants one for personal use and to experience ground up saw builds for the first time- just as you have done.
I despise those that buy the damn things, build them and try to sell them off as OEM.

But all that is neither here nor there, with this particular thread, you have some great advice- knockoff carbs are known to give trouble.
What is perhaps best for you is to find a used OEM 371/372 or 2171/2172 carb and have it kitted by someone that knows carbs and can set it up as near good as factory new- then you can take the carb out of the equation (although I am willing to bet a well set up OEM carb will solve your issues).

Kit saws are fun when they go good- not so good when they do not run well and you cannot put your finger on exactly why that is.

 

[9050LX]

I have sorta tried pulling on that vent hose thinking the same thing before I bought the second tank, but your right now that i dont absolutely NEED that tank i could try it and if I screw it up in the name of science and helping others then so be it. Matthew Olsen on youtube I think does something with them tank vents but I'm not sure if it's the same style or not I dont think his video showed him removing it.

I would run an echo type vent on top by carburetor or just leave it open without vent til carb is sorted out.

 

[Alanmurphy6912]

Now be fair, sometimes there is never enough information shared or rather the correct kind of information shared for responders to guess the correct diagnosis.
Then factor in the fact you are asking about a family of "saws" some people dislike the very notion of and thus decide to skip over the posts rather than reply- and a lot of those folk are very good servicers of chainsaws!
Copycat saws are fine for anyone that wants one for personal use and to experience ground up saw builds for the first time- just as you have done.
I despise those that buy the damn things, build them and try to sell them off as OEM.

But all that is neither here nor there, with this particular thread, you have some great advice- knockoff carbs are known to give trouble.
What is perhaps best for you is to find a used OEM 371/372 or 2171/2172 carb and have it kitted by someone that knows carbs and can set it up as near good as factory new- then you can take the carb out of the equation (although I am willing to bet a well set up OEM carb will solve your issues).

Kit saws are fun when they go good- not so good when they do not run well and you cannot put your finger on exactly why that is.

Yes sir. I know m way around carburetor s pretty well myself. I have a handful of different rebuild kits for them here in the shop,and I have all the tools to test,and set the metering lever and all that also. I've spent alot of time with all my saws every single saw I've owned with the exception of 2 in the past uve completely torn down and cleaned amd or rebuilt. I end up with saws that people throw out,or blow up and want to sell cheap and i go thru and clean clean clean,(seems like nobody cleans the inside of there saws out) lol and give them whatever they need. And because of this I have 5 or 6 great running reliable saws. I just in the last few years found out about the kit saws and whatnot and was ecstatic lol only because I love to build amd diagnose them. I also love running them and being in the woods. I'm no pro logger but i used saws almost year round. And yes I am with you I hate being people selling them as oem when it's easy to tell that they aren't of you know what your looking at. And I've also ran into that where folks dont wanna help or even speak to you if you tinker with non oem saws. My local stihl dealer who I go to often and have a good relationship with sorta laughed at me for even owning one so yea I 100% understand that also. Believe me I'm sure I speak for all of us when I say, "I'f stihl or husqvarna sold kit saws for even remotely close to the same price,we would build oem saws" but that's just not the case. So I agree with you. Now with that all said,I've had some time to run the saw again a bit and it seemed to run okay I actually got thru a full tank of fuel without it stalling on me... however it did take a little tuning and did bog out a few times in no particular order. I would crack the cap and no pressure would come out so idk and it also didnt. Change the way it ran. Anyway I'm at my bench with the old original tank out and trying to pull the vent to check it out and this is what it looks like so far. Last pic is inside of the tank. Cant see the end of the vent.

 

[Alanmurphy6912]

I would run an echo type vent on top by carburetor or just leave it open without vent til carb is sorted out.

The new tank that's on the saw doesnt have a hose for me to do that. It literally has like a golden colored honey comb looking thing in the tank hole for the vent. And is non removable I do believe

 

[Alanmurphy6912]

I was surprised how hard an OEM tank vent pulled to remove it. I wouldn't have tried so much if I hadn't had the reassurance of someone in the know. I wouldn't doubt that the hose separates and you have to extract the rest with a screw or something look up a pic of the OEM vents to see how they look and snap fit into the case or do the UTube thing to get an idea of what you are getting into/

I've looked up the oem vents and there are a few different colors and styles I'm not sure which one of even need.

 

[Alanmurphy6912]

I would run an echo type vent on top by carburetor or just leave it open without vent til carb is sorted out.

This is the vent I'm assuming is in my new handle that is on my saw. Has that same gold colored thing in the end. And in other news,I just broke a hardened steel screw off in the brass plug on my old tank... so now it's going to be even more fun and liberal cursing to get it out.. might quit on it for tonight. Starting to be murphys law around here..

 

[TRTermite]

The new tank that's on the saw doesnt have a hose for me to do that. It literally has like a golden colored honey comb looking thing in the tank hole for the vent. And is non removable I do believe

That golden colored is a sintered bonze/brass and I believe it is shinier/glossier on one side than the other. glossy side in. Recollecting some lost learning here so hopefully some body will jump in. It went in after the part...that looks like a long slender straight trumpet (I think) I just saw that you slipped a pic/post in and I missed it

 

[TRTermite]

This is the vent I'm assuming is in my new handle that is on my saw. Has that same gold colored thing in the end. And in other news,I just broke a hardened steel screw off in the brass plug on my old tank... so now it's going to be even more fun and liberal cursing to get it out.. might quit on it for tonight. Starting to be murphys law around here..

You should know about Murphy judging by your avatar.

 

[9050LX]

Just run a vent tube up to or above the carb somewhere without a vent for now is my vote.

 

[huskihl]

Vents…
Older saws (up to 2005? 10?) or so vented both ways. Epa put restrictions on them so now they can only let air into the tank to replace fuel as it’s used.
If you pull vacuum from the outside and it holds, you can remove the sintered piece and check for a rubber disc inside. And then only reinstall the sintered piece. Removing the rubber check valve makes it to where it will vent both ways.

Pop off pressure in the carb needs to be up around 15 psi (if you still have a 1-way vent) to hold back tank pressure. If popoff is too low, pressure in the newer tanks can push open the needle in the carb and allow fuel to flow into the engine. Most newer Stihls and Huskies have upwards of 25-30 psi pop off pressure to hold back the pressure in the tank

 

[Alanmurphy6912]

You should know about Murphy judging by your avatar.

Yes that's my actual name. Alan Murphy. And murphys law states "anything that can go wrong,will go wrong"

 

[Alanmurphy6912]

Just run a vent tube up to or above the carb somewhere without a vent for now is my vote.

That's not possible with my tank that is on the saw currently. At least not that I'm aware of. Because it has that vent like I posted a picture of from ebay with the brass mesh in the end. The other pics I posted are of my old original tank that I was trying to pull the vent out of and it had a hose on that nipple that did go up over the carb and just hang out for awhile when I built the saw. And now that I've tried getting the nipple ot of the tank and got a hardened steel tap broken off in it it's not wanting to come out. I'm probably gonna have to use my little wood burner with a small hot knife scalpel blade in it and ever so slightly cut a relief in the black plastic around the nipple that is part of the vent to get it out. I have tried needle nose etc and it will turn,but womt pull straight out. I cannot get a good enough grip to pull it straight out.

 

[Alanmurphy6912]

Yes awesome info thanks I can try it. I do know that my pop off pressure of both chinese carbs I have is over 25psi that my tester pushes because I have tested both carbs and it will not pop and let the pressure off with my small tester pumped all the way up.

Vents…
Older saws (up to 2005? 10?) or so vented both ways. Epa put restrictions on them so now they can only let air into the tank to replace fuel as it’s used.
If you pull vacuum from the outside and it holds, you can remove the sintered piece and check for a rubber disc inside. And then only reinstall the sintered piece. Removing the rubber check valve makes it to where it will vent both ways.

Pop off pressure in the carb needs to be up around 15 psi (if you still have a 1-way vent) to hold back tank pressure. If popoff is too low, pressure in the newer tanks can push open the needle in the carb and allow fuel to flow into the engine. Most newer Stihls and Huskies have upwards of 25-30 psi pop off pressure to hold back the pressure in the tank

 

[TRTermite]

Yes that's my actual name. Alan Murphy. And murphys law states "anything that can go wrong,will go wrong"

Class mates Jim and John Wright(twins) We razzed 'rm at times like - Two Rights don't
"ALWAYS" make a Wrong Never thought of combining Murphys' Law with it.