John Deere Generator hard to start.

[Chucksta]

So, here's the tale of woe... A freebie generator with a no start problem. Put in enough oil to make sure the low oil shutoff stayed off ( it had almost no oil in it ). Traced lack of fuel flow to a piece of crud in the tank inlet. Cleaned float bowl.. No appreciable grunge. Fresh 94 Octane ethanol free fuel.. Can of SeaFoam ran through it. Starts and runs, but only with a shot of quick start. Screw it.. new carb for it.. checked and set valves... Still the same, it runs O.K., once you get it going, but it still needs a shot of quick start to get it going..
I'm stumped... any ideas??
Model 030419
Briggs and Stratton 342 CC 1650 engine series.

 

[GMB74]

Does it fail to start only when cold, or also fail to restart when warmed up?

Choke closing fully?
Weak spark due to failing coil?
Air leak in the intake system?
Low compression from being run low on oil?
Plugged muffler/exhaust?

 

[Chucksta]

Yup.. the choke fully closes
Spark seems fine.. tested with an in line tester.. I had no spark until I filled the oil up. New plug made no difference.
Air leak? doubtful... gasket is fine, and the new carb seemed to seal well.
I didn't check the compression per say, but it really feels healthy when you yank the starter cord. It feels like it's healthy.
Plugged muffler / exhaust.? Well I could see that something like that might make it run like a bag of hammers.. once it got started.. But not stopping it from firing up or at least popping when yanked.

You can pull it till you are sweating like a pig... Nada.. -30 ( F ), or 90 (F).. it doesn't matter.. But, toss a shot of ether in it and it roars to life on the next pull. You don't even have to pull the air cleaner.. Just spray a bit of starter fluid from underneath.. Then it runs fine, doesn't stall, works as it should.. It's just that it won't start without spray... at any temperature.
I don't want it, I don't need it, and all I've got into it is about $75.00 for a carb, new oil, Seafoam, and fresh gas.

But, there's no way I'm gonna get any coin for it if it needs spray to start.

Carbs on these models have zero adjustments for mixture. ..

 

[GMB74]

Is your replacement carb a genuine OEM carb or aftermarket Chinese carb?
Aftermarket carbs are hit or miss.
You may have a "miss" here.

 

[stretch5881]

A valve not sealing causing vacuum to not build, a vacuum leak causing the same, or the idle circuit in the carb is faulty.

 

[Chucksta]

Is your replacement carb a genuine OEM carb or aftermarket Chinese carb?
Aftermarket carbs are hit or miss.
You may have a "miss" here.

Amazon POS.. But the interesting part is that the symptom is the same with the original carb, or the replacement.. Runs fine, once started, won't start without spray.

 

[Chucksta]

A valve not sealing causing vacuum to not build, a vacuum leak causing the same, or the idle circuit in the carb is faulty.

Would I be correct in assuming, that if it shows proper compression, that the valves are fine?

 

[stretch5881]

Would I be correct in assuming, that if it shows proper compression, that the valves are fine?

A leakdown test would be the only way to make sure the valves are sealing.
There does need to be sufficient vacuum to draw fuel from the carb.

 

[GMB74]

stretch5881 is correct about the leakdown test.
These engines have an automatic compression relief for easy hand starting. A compression test will give a very low and misleading reading.

 

[MS261CM]

Weak ignition? Looks like you've investigated everything else.
I don't know if starting fluid makes it any easier to start an arc in but I know natural gas is more difficult.

I would try a smaller gap, a plug with a finer electrode or both.
If any of that helps, start looking at magneto gap, plug wire and ignition module (coil).

Voltage generated is basically proportional to RPM so once it's started things would be expected to improve.

If you spend countless hours chasing these issues with nothing to show - I never typed this.

 

[RCBS]

Try running (adjusting) the valves. Shouldn't take 10 minutes.

 

[Wonkydonkey]

stretch5881 is correct about the leakdown test.
These engines have an automatic compression relief for easy hand starting. A compression test will give a very low and misleading reading.

I,m wondering if the auto compression relief isn’t working as it should, ie sticking open, then there’s just not enough compression for it to fire but throw some ether in it and it pops.

I'd guess rings could be abit warnout and not helping when cold either..

I,m wondering if you could disable the auto decompression spring or something