reo sno thro h60 governor issue

[tspot100 2]

my 66 REO SNO THRO tecumseh h60 governor is driving me nuts. the motor idles great but as soon as any amount of throttle is applied and the governor moves at all, the motor sputters and dies. 

compared it externally to my 72 wheel horse trailblazer 7 and it is identical. carb has been overhauled last year and ran well. put another known good carb on and same symptoms occur as soon as governor linkage moves at all. any other places to look before splitting the case and looking at the internals?

exactly like this gov pic i found in the gallery.. not my motor. 

thanks in advance.

[Snoopy11 5,714]

Buddy... to me from an engine builder's standpoint.... it sounds like a fuel issue somewhere along the line... maybe bad fuel line... clogged jet... etc.  

 

I was wondering if you have tried one thing... if you physically move the governor with your hand, and it dies...?

 

Basically, when you move it with your hand, you are bypassing the governor. 

 

Does it act differently if you leave it on choke?

 

I do not think it is an internal issue... just my take on this. However, have you checked the valves, specifically the intake valve lash setting... just to make sure it is within specs?

 

Don

[Snoopy11 5,714]

I realize that you said that you put a known good carb on it...

 

BUT have you taken apart the carb and actually cleaned it?

 

I would invest in these little guys here... they are a lifesaver... 

 

 

Don

[Snoopy11 5,714]

What I am thinking here is... when you open the governor... it is opening the 'flap' for air/fuel to enter the combustion chamber. When you pop the governor... the mixture is incorrect... therefore... it stalls. 

 

If we correct the mixture... when you pop the governor, it should continue running. To test this temporarily... buy some carb cleaner... remove the air filter. When you pop the governor (throttle it up) spray carb cleaner into the intake and see if it continues running, idles up. 

 

If so, you know that you need more fuel. If the main jet is clogged, or possibly not allowing enough fuel, this would cause your issue. 

 

Do this test, and let us know the results. 

 

Don

[tspot100 2]

i  cleaned the carb when i rebuilt it. new fuel line as well. does the same sputtering if choke is on or off.  any movement of the gov linkage, by hand or otherwise.. will make the motor sputter and backfire. i have not checked the valve clearance in years... mabey the next step? will  check points and timing as well if i end up disassembling.

no air filter on this blower. i have sprayed cleaner  when running and no change... same sputter/backfire...

double checked the carb and jets all seem clear. running out of ideas here..

thank you for the input. 

my problem is that i love this old blower!

Edited November 18, 2021 by tspot100

[gwest_ca-(File Mod) 11,046]

Is this a carb with a jet up from the bottom. If it is removed for cleaning it needs to be replaced because the jet holes will not line up. A replacement jet has a groove machined around the jet in the orfice location so the fuel can get through.

Have never seen one but will guess a file could add a groove in the original jet.

Why this happens is when made the hole in the jet is drilled after the jet is installed. Now you have no way of lining up the holes.

[tspot100 2]

yes..jet up from the bottom. wasnt aware of this...hmmm. may have to get a jet and another rebuild kit. its a lmb labeled carb. questioning now if this is the original carb...

good thing i enjoy working on these small engines..

thank you

[Handy Don 12,235]

3 minutes ago, gwest_ca said:

Is this a carb with a jet up from the bottom. If it is removed for cleaning it needs to be replaced because the jet holes will not line up. A replacement jet has a groove machined around the jet in the orfice location so the fuel can get through.

Have never seen one but will guess a file could add a groove in the original jet.

Why this happens is when made the hole in the jet is drilled after the jet is installed. Now you have no way of lining up the holes.

You may be onto something here, @gwest_ca.

 

@tspot100

Does the "known good" carb run correctly on a different engine (which to me is the only way to confirm "known good")?

Did you try turning the throttle plate by hand to see if it'll go to higher revs?

If it simply won't run at full speed, then it sure does, to me, sound like it is not getting fuel/air when it wants it. So it's either the carb or the intake valve.

 

I use this for trouble shooting my Tecumseh carbs: 

Tecumseh Carburetor Identification & Troubleshooting SM.pdf

 

And this one for everything else:

Techumseh Technician's Handbook.pdf

[gwest_ca-(File Mod) 11,046]

Looked for a picture of one and found this. I am just going by what I have read.

[Handy Don 12,235]

This is only relevant for a carb with a replaceable jet. Not all Tech carbs had replaceable jets.

 

The blue arrow is the end toward the bowl. The hole at the orange arrow is where fuel enters the jet after coming in through the hole in the side of the carb main jet barrel (see below). The red arrow is the nozzle sticking up into the venturi that disperses the fuel into the airstream.

 

 

The green arrow points to the main jet "barrel". The fuel inlet is a tiny hole drilled into the side of the barrel high enough from the bottom that is above both sets of theads on the main jet. (A non-removable jet has the same construct but there is no "slot" for a screwdriver at the blue-arrow end to remove it.)

Edited November 18, 2021 by Handy Don

[tspot100 2]

thank you. the known good carb came off my trailblazer 7 which runs very well. will keep trying to diagnose this tomorrow..getting dark here in nys

[Snoopy11 5,714]

2 hours ago, Handy Don said:

carb or the intake valve

My thoughts exactly, HD... 

 

Don 

[Snoopy11 5,714]

One thing that I notice here though... @tspot100 says that it is backfiring... VERY uncommon with lack of fueling. Sounds like not enough air... definitely may be an intake valve...

 

I would pop the valve cover and take a look... just to make sure it isn't something easy... like a valve adjustment...

 

Don

[tspot100 2]

thank you for the tip to check the valves. checked valve clearance...both intake and exhaust at .010" at tdc w both valves closed.

for verification of carb issue i put the trailblazer 7 carb on the reo and had the same backfiring issue. does not seem like a fuel delivery issue, so i checked the valves. 

i have 2 books and both have different valve clearance specs...the L head book says .008 and .012 but the other book says .010 for both valves.

which clearance is correct? it is an h60-75072B.

 

[Handy Don 12,235]

Not sure what your second source is, but I would stick with the .008/.0012 that's in the Technician Handbook that I uploaded. But before I set the valves, though, I'd pull the head to make sure the valves are not excessively worn or not seating correctly and that you don't have excess carbon up there.

 

[tspot100 2]

2nd source is a chiltons small engine repair manual.

will pull the head and check em out. thank you for the help. 

intake valve is shorter than spec so a new valve is in order.

may replace exhaust as well because seems right to do while i have it apart/

still wondering how this gives the symptoms i have.. sputtering thru the carb

will report back when done

thank you again

[Handy Don 12,235]

1 minute ago, tspot100 said:

2nd source is a chiltons small engine repair manual.

will pull the head and check em out. thank you for the help. 

intake valve is shorter than spec so a new valve is in order.

may replace exhaust as well because seems right to do while i have it apart/

still wondering how this gives the symptoms i have.. sputtering thru the carb

will report back when done

thank you again

Sounds to me like you are on it! Best of luck.

I understand, as I think do all the members here, the determination to repair machinery that has given good service and has life left.

[tspot100 2]

quick update...

pulled head and cleaned everything up while waiting on parts.. intake valve on backorder with jacks small engine...must be on one of those cargo ships!

not much carbon on exhaust valve. piston top quite clean as was the head.  

remeasured valve gap while everything apart got a more accurate reading , exh-.008", int-.009". 

thanks again and hope all had a good holiday

[tspot100 2]

update.

finally got the valves from jacks..

installed last nite and fired her up this morning..

you all were right! it was the valves! specs at .008 and .012 and runs very well. thank you all again for the direction..i was sure it was the governor..

i have alot to learn.

thanks again