HT131 help before I crush it for good

[DELETED (Struggle)]

My trusty HT131 I have ran quite a bit for the last five years has turned into a useless pile yesterday. It will idle all day long but won't accelerate and dies when throttled. Put a new coil on it. Checked carb nozzle per tree Monkey and it's all good. Tried various settings on valves. Switched a used coil off a 101 and carb off that saw as well to no avail.

Put a new impulse line. Vac test no leaks with carb block in place.

What it acts like is that it won't push the needle valve down. It acts like no high-side circuit and is working.

I removed valves and removed carbon off exhaust valve.

Start it idles fine then throttle it and it dies almost instantly

Also I had a new accelerator pump and installed that and no change




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[Onan18]

Spark arrester plugged?

 

[Whiskers]

I had a 4 mix blower acting up, and I used the stihl decarbonizer treatment and it fixed the problem. It sounds like you cleaned the valves though?

 

[cus_deluxe]

I dunno, but the last place i worked we had i think 5 br600's (i know, different engine but still 4mix). Every one of em ended up as a parts unit with those exact same symptoms, after an equal amount of fartin around and parts swapping. Do the little ones have the same plastic cam gear thingy like the blowers? If so that could be ur problem.

 

[hseII]

My trusty HT131 I have ran quite a bit for the last five years has turned into a useless pile yesterday. It will idle all day long but won't accelerate and dies when throttled. Put a new coil on it. Checked carb nozzle per tree Monkey and it's all good. Tried various settings on valves. Switched a used coil off a 101 and carb off that saw as well to no avail.

Put a new impulse line. Vac test no leaks with carb block in place.

What it acts like is that it won't push the needle valve down. It acts like no high-side circuit and is working.

I removed valves and removed carbon off exhaust valve.

Start it idles fine then throttle it and it dies almost instantly

Also I had a new accelerator pump and installed that and no change




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@sawdoc

 

[Sleeper]

Plastic cam gear thingy? Wow, sounds like cheaping out on a critical part.

 

[DELETED (Struggle)]

No screen in exhaust and it is clear. I. Yes it has the plastic cam gear. Everything there appears ok on it as see no visual issues. The pins are fitting properly no major play in there proper places.

Fuel filter has no restrictions and line holds vac no leaks


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[CR888]

The 130 is prone to soak the air filter with fuel, check your filter is not soggy or remove it and try. Sounds frustrating.

 

[DELETED (Struggle)]

No filter on it currently while test running it. I did remove the cam and removed the decomp weight on the cam and I was able to slowly get it to rev. It has if you throttle up in normal use it falls on its face and dies.

I could tell little difference in how hard it pulls over with decomp removed. It has been tough to start from compression acting like the decomp set up isn't working so maybe someone is familiar if this affects valve timing? Nothing looks physically wrong


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[Adirondackstihl]

Fuel filter

 

[trooney]

Try a new carb??

 

[Simondo]

Primmer /purge circuit (I assume your USA 131 has a bulb on the carb) playing up ...non return valve in the block can be a right head scratcher . How is the bulb when you pump it ? fill right?

 

[TJ the Chainsaw Mechanic]

If the valves aren't seating it will idle and not take a throttle as the charge is running right past the valves. I had one that had low compression and would barely idle. Got it to run at a fairly high idle and took Sea foam spray and ran that stuff in it until until I could run it full throttle. Had great compression after that.

 

[DELETED (Struggle)]

Volume to carb isn't issue. Filter is ok

The bulb fills up normally has no issue pulling fuel up.


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[Simondo]

No filter on it currently while test running it. I did remove the cam and removed the decomp weight on the cam and I was able to slowly get it to rev. It has if you throttle up in normal use it falls on its face and dies.

I could tell little difference in how hard it pulls over with decomp removed. It has been tough to start from compression acting like the decomp set up isn't working so maybe someone is familiar if this affects valve timing? Nothing looks physically wrong


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I look for a sign the valve clearance is slack when the comp is higher than norm at start due to the auto dec comp not working properly and as far as i know its just a leak off situation rather than a timing change.

 

[DELETED (Struggle)]

I removed the decomp arm off the cam to eliminate any issue with that. Did a leak down test at 70 psi I'm losing just under 2 psi.

Put a new carb on it and runs exactly as before. Try to idle up it dies. It will idle all day long though. Very frustrating. I have trimming jobs being held up by this machine.

I looked at the echo 280 today but absolutely dislike the loop handle design.


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[DELETED (Struggle)]

Pressure test block and sprayed down with water no leaks


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[hseII]

I removed the decomp arm off the cam to eliminate any issue with that. Did a leak down test at 70 psi I'm losing just under 2 psi.

Put a new carb on it and runs exactly as before. Try to idle up it dies. It will idle all day long though. Very frustrating. I have trimming jobs being held up by this machine.

I looked at the echo 280 today but absolutely dislike the loop handle design.


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I really like my PPT-280. For all the reasons you don't like the Stihler, & I'm a Stihl Head.

 

[tree monkey]

I believe you can buy just the engine if all else fails

 

[DELETED (Struggle)]

I believe you can buy just the engine if all else fails

I don't want to accept defeat just yet but gosh am I getting close. Going to get a timing light next


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