350 Rancher Engine problems

[Deleted member 3748]

I swapped from Autolite to NGK. That’s all the parts place had.
I didn’t see it spark outside the engine, but I’ll go take a look.
—edit—
Update. That’s a big 10-4 @PistonHonda confirmed sparking. (Better than the Autolite 4164, actually)

You have spark and you have fuel. Next check should be compression.

 

[Admin]

 

[snuffnwhisky]

Make sure your getting a good blue spark at the plug. Red or orange is not good. You can also choke it and spin it over good and pull the plug and see/smell gas. You can buy a compression gauge pretty cheap. I think the parts stores also have some for rent.

 

[JsheII3]

Make sure your getting a good blue spark at the plug. Red or orange is not good. You can also choke it and spin it over good and pull the plug and see/smell gas. You can buy a compression gauge pretty cheap. I think the parts stores also have some for rent.

O’Reillys for $39 “rental”. 2 days. Return it for my $39 back.
It’s called a tool loaner program.
I asked why... they said lots of times ppl just keep the rentals.
That’s pretty cool.

So I got one. Did have to buy a $10 adapter to get it to thread into ATV.

Headed home to give the compression a test.

What numbers should I hope to see?

 

[Cyberjunk]

Could be CDI or stator , they do funny with spark


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[Cyberjunk]

Could be CDI or stator , they do funny with spark


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Or a tight valve


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[DG Rider]

O’Reillys for $39 “rental”. 2 days. Return it for my $39 back.
It’s called a tool loaner program.
I asked why... they said lots of times ppl just keep the rentals.
That’s pretty cool.

So I got one. Did have to buy a $10 adapter to get it to thread into ATV.

Headed home to give the compression a test.

What numbers should I hope to see?

Make sure the battery is charged well and that you hold the throttle wide open while testing.
Should be around 99psi or so.

 

[JsheII3]

Make sure the battery is charged well and that you hold the throttle wide open while testing.
Should be around 99psi or so.

Uh-oh... <30psi.
The needle moves, but immediately goes back down. It never gets over 30

 

[snuffnwhisky]

Not good. Sometimes you can pour some oil in the spark plug hole and retest. If the compression goes up, its usually a ring problem. If not, valve or head gasket issue.

 

[snuffnwhisky]

The easiest first checks would be the valve clearance and timing marks.

 

[JsheII3]

Not good. Sometimes you can pour some oil in the spark plug hole and retest. If the compression goes up, its usually a ring problem. If not, valve or head gasket issue.

Ok. Hang tight. Will update.
—Update—
With a capful of oil... 20psi is the highest needle.

 

[JsheII3]

The easiest first checks would be the valve clearance and timing marks.

At that point, I’ll have to bring it to somebody.
It’s ok.
Any idea of estimate repair.
I’m contemplating buying a new(er) one.

 

[DG Rider]

Uh-oh... <30psi.
The needle moves, but immediately goes back down. It never gets over 30

Negative. Needle should never go down. There should be a check valve (usually. Schrader) in the gauge that is stuck or missing, OR the gauge is damaged.
Doesn't sound promising...but the gauge is giving false info at this point, so let's fix that.

 

[Cyberjunk]

And you need to hold the throttle wide open while testing compression


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[Cyberjunk]

And you need to hold the throttle wide open while testing compression


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Will read low if you do not


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[JsheII3]

Negative. Needle should never go down. There should be a check valve (usually. Schrader) in the gauge that is stuck or missing, OR the gauge is damaged.
Doesn't sound promising...but the gauge is giving false info at this point, so let's fix that.

Yeah. The gauge has a release valve on the side to move the needle back down (I suspect). But the needle goes down in its own. I hooked it to my air compressor to see if the gauge matched my air compressor gauge. It did. But immediately reset to zero without my pushing the button.

I took the compression test to my 2014 Foreman. It reads 90.
Needle still drops, but I can watch it reach 90 as the engine turns.

I don’t doubt my loaner compression tester is defective. But I think it’s still telling me some bad news.

 

[70Bones]

Update.
Still won’t run.

1. New spark Plug
2. Drained gas tank and removed screw ( @lee / @snuffnwhisky ) from bottom of carb bowl until dry.
3. It does appear to have compression at the recoil. Noticeable difference with and without spark plug installed.
4. I also tried numerous tips like pour gas directly into air intake carb. Choke and cover air intake. Spray WD40 in carb and in top of piston.

So... if it ran hot because of low oil, what damage could it cause to keep it from cranking?
Or any other things I could try before taking it into the shop. ??

It appears that you described the problem... you said you drained the carb bowl until the gas stopped... the gas shouldn't stop until the tank is empty. If that's the case, you're carb is not getting gas. Gas filter? or the float valve is plugged? (assuming it's a gravity fed carb). If it has a fuel pump, turn on the key for a sec and make sure gas is getting into the carb (while the plug is out of the bowl).

 

[DG Rider]

Yeah. The gauge has a release valve on the side to move the needle back down (I suspect). But the needle goes down in its own. I hooked it to my air compressor to see if the gauge matched my air compressor gauge. It did. But immediately reset to zero without my pushing the button.

I took the compression test to my 2014 Foreman. It reads 90.
Needle still drops, but I can watch it reach 90 as the engine turns.

I don’t doubt my loaner compression tester is defective. But I think it’s still telling me some bad news.

Yes, that's exactly what the valve is for. The gauge should hold the highest rating. But... If it's giving 90 on your Foreman then it's probably being fairly accurate . Just make sure there are no leaks any point in the hose or where it screws in. Don't want to tear down the engine over a torn o ring or loose connector.

Oh...for the record, I had a brain fart and gave you a compression spec for a 2014 Foreman. The rancher might be different, but no way it should be that low.

 

[JsheII3]

It appears that you described the problem... you said you drained the carb bowl until the gas stopped... the gas shouldn't stop until the tank is empty. If that's the case, you're carb is not getting gas. Gas filter? or the float valve is plugged? (assuming it's a gravity fed carb). If it has a fuel pump, turn on the key for a sec and make sure gas is getting into the carb (while the plug is out of the bowl).

Sorry, that should have read...
I pulled fuel line off petcock valve at the tank. Drained the entire tank.
While simultaneously opening the bowl screw. It had to stop since not being fed from gas tank.

I also blew compressed air in through the carb every direction.

 

[JsheII3]

Yes, that's exactly what the valve is for. The gauge should hold the highest rating. But... If it's giving 90 on your Foreman then it's probably being fairly accurate . Just make sure there are no leaks any point in the hose or where it screws in. Don't want to tear down the engine over a torn o ring or loose connector.

Oh...for the record, I had a brain fart and gave you a compression spec for a 2014 Foreman. The rancher might be different, but no way it should be that low.

I researched what 30psi could mean on the worldwide web. Just to see repair estimates...
Anyways, I learned about decompression valves. To help turn engines over. Some say 68psi is where you’ll see them kick in on Honda (ex300/400) forum I was reading.

But no-one seemed to think 30 was a good reading. Lulz

 

[Deleted member 3748]

I pulled fuel line off petcock valve at the tank. Drained the entire tank.
While simultaneously opening the bowl screw. It had to stop since not being fed from gas tank.

I also blew compressed air in through the carb every direction.

30 psi is the culprit. Since it slowly got worse while riding, I'm thinking the low oil was causing excessive cylinder wear/ring wear. How long will it take to pull the head off and look? Do you have one of the little borescopes (camera at the end of a hose)? I bought one to peek into the cylinder of my F150 and it works great for many things. They're about $30.