Generator Starts But Won't Stay Running

[David Green]

Hi All, Stihlonly sent me over. He says hi. I'm not a newbie, but I'm not exactly an expert either.

5500W DeVilbiss Generator (I think now they are owned by Porter Cable)
10 HP Tecumseh HM100 Engine also says 159409P on the tag

I'm trying to get it running for someone. It used to run, as far as I know it hasn't run in at least a year.

I can spray starting fluid into the intake, choke it, engine will catch on the first pull but won't stay running. Without starting fluid it won't catch at all. I've replaced the fuel filter on the gravity feed fuel system, drained and replaced all the gas with fresh and replaced the carb - the new one was cheaper than a rebuild kit.

So this is acting like it's not getting fuel. The new fuel filter has a clear body, I can see it fill with fuel. I loosened the bowl nut on the carburetor, it's definitely getting fuel to the carb. I did not adjust the carb or do much to it when I got it except put it on. So there's a possible float issue, clogged jet etc on the new carburetor. You can see in the link to the carb that the gasket doesn't have an offset so I can't see a way to put it on incorrectly.

Things that I've yet to check
oil level, I may just change the oil. I don't have a reason to expect its low. I don't know if this generator has a low oil cutoff but it might.
replace the fuel lines, one might be restricted so that some fuel is getting to the engine but not enough

Spark plug, but I can't see how this is an ignition issue.

Is there anything else? it is acting very much like a fuel problem.

 

[Lone Wolf]

Hi All, Stihlonly sent me over. He says hi. I'm not a newbie, but I'm not exactly an expert either.

5500W DeVilbiss Generator (I think now they are owned by Porter Cable)
10 HP Tecumseh HM100 Engine also says 159409P on the tag

I'm trying to get it running for someone. It used to run, as far as I know it hasn't run in at least a year.

I can spray starting fluid into the intake, choke it, engine will catch on the first pull but won't stay running. Without starting fluid it won't catch at all. I've replaced the fuel filter on the gravity feed fuel system, drained and replaced all the gas with fresh and replaced the carb - the new one was cheaper than a rebuild kit.

So this is acting like it's not getting fuel. The new fuel filter has a clear body, I can see it fill with fuel. I loosened the bowl nut on the carburetor, it's definitely getting fuel to the carb. I did not adjust the carb or do much to it when I got it except put it on. So there's a possible float issue, clogged jet etc on the new carburetor. You can see in the link to the carb that the gasket doesn't have an offset so I can't see a way to put it on incorrectly.

Things that I've yet to check
oil level, I may just change the oil. I don't have a reason to expect its low. I don't know if this generator has a low oil cutoff but it might.
replace the fuel lines, one might be restricted so that some fuel is getting to the engine but not enough

Spark plug, but I can't see how this is an ignition issue.

Is there anything else? it is acting very much like a fuel problem.

Clean the new carb maybe dirt from the old tank got in.

 

[David Green]

that is a possibility. I'm also going to replace the fuel lines and check the low-oil switch (and the oil though I don't expect it to be low).

 

[Lone Wolf]

that is a possibility. I'm also going to replace the fuel lines and check the low-oil switch (and the oil though I don't expect it to be low).

It fired on a shot of gas prob the carb not the switch.

 

[Al Smith]

If I'm not mistaken that engine might have an impulse type fuel pump that works just like a chainsaw carb .It may or may not be made by Walbro .If it does it's not unusual for the check valves and or pump diaphragm might have became stiff from just sitting idle .Some times they just need freed up or they might need to be replaced .
I had a similar situation on either a pressure washer or gen set both with Briggs engines .On the Briggs just these two items are less than 10 bucks .I might also mention if the fuel and impulse lines get crossed it won't work---yes I did do that .

 

[AVB]

The Tecumseh HM100-159409P uses a 640152 carburetor which is a standard float style.

 

[backhoelover]

certain tecumseh carbs have floating idle tubes. ill have to see a pic of the carb to know. if it is that style carb when you take it apart you need to shake it and see if you hear a rattle, if it is that certain style carb and you dont hear a rattle you might never get that carb to idle

 

[backhoelover]

i have some pic on my computer where i cut one open. ill see if i can find them and post the pics, so yall can see what im talking about

 

[AVB]

If the IPL is correct on which carb it has then the float bowl retaining / main jet (item 40) is likely clogged, Also the idle mixture restricter jet (item 20) also tends to clog. Some techs think it a mixture adjustment but it is not.

 

[backhoelover]

start at 22 min in

 

[Fish]

Those low oil switches can bw touchy, allow it to start until the oil gets slung around a bit, and then the oil level drops enough to let the switch shut it down. Top off the oil so it is full.

 

[Trevj1]

I have met a couple mechanics that had no idea that some of the newer carbs have a little bitty jet orifice half way up the side of the main tube of the carb that needs to be cleaned out if the carb is left sit full of skanky gas.

As the OP says he bought a new complete carb, probably not the carb giving grief though. Unless the carb was not installed completely correctly, springs all in the correct locations, etc.

Pulling the oil shut-off switch wire is one way to check that. Pull the ground (shut off) wire off the carb linkage too if it has one.

I have resorted to using a spray bottle of fuel and simply feeding the stuff into the inlet in order to prove or disprove that the issue was in fact, a lack of fuel. Once you rule out that it isn't just that the engine just doesn't run, then you work on fiddling the carb to make it run properly, as that is where the problem is. If it won't start and run on the spritzes of fuel, then make it run first, then make it run well.

All assumes clean fuel system, flow through the lines, and reasonably fresh gas throughout. Gotta be fuel mixture, ignition, compression, or plain ol'd mechanical stoppage.

 

[Al Smith]

This might or might not have a thing to do with the problem .My home built splitter has a flat head 11 HP Briggs electric start engine .It had became a problem running lean so I ran it at partial choke mainly because I was too lazy to address the problem .All it was was a leaky gasket where the carb connects to the intake manifold .
No big deal,little ball peen hammer and a piece of cardboard from a case of Bud Light ,new gasket ,back in business .Took all of 15 minutes more or less .

 

[Trevj1]

I inherited a BCS two wheel tractor with a 8 HP Kohler that had that exact problem. Loose intake manifold. Didn't even have to put a gasket in, just tightened it down. Been good since!

 

[KevinSalyer]

Why not clean it first, remove the scale and rust and then run it again. There must be problem when it is not running for a long time.