My Briggs and Stratton 18.5 HP I/C, Twin II engine was running fine. I went to idle and then quickly opened to full throttle and after 2 seconds or so it quit and now will not restart. I have good spark, fuel to the pump, but it will not start after many attempts. Any suggestions would be helpful. Thanks in advance!!!

flyguy

 

Post the model number of your engine so we know exactly what you have.

Did you command the engine to quickly go from idle to full throttle or did the engine do it on it's own? Did the engine make any odd sounds when it quit or does it make a different sound now when you try to start it?

 

Check the oil level.. Empty?

 

The oil level is good.

The complete Model is a 18.5HP I/C Model 42D707 type 2280 E1 code 9904245A
Briggs and Stratton.

 

I moved the throttle from idle to full throttle, when it stalled there was not any engine noises, it just sputtered a couple of times and died.

 

Does it have compression?

 

yes, I do not have a compression guage but when it turns over with the starter, the first rotation is slow and hard, with a new starter and the battery at full charge producing 13.6 volts

 

Are you getting fuel inside the carburetor through the float valve? It may be that you have fuel at the pump, but that's as far as it goes.

 

Are the spark plugs wet?
_______________________

 

Yes, I have fuel in the carb bowl and at the plugs. Just rebuilt the carb. with new needle valves and gaskets, plus cleaned completely with Gunk, still will not start.
Checked spark and with plugs removed they are sparking.

 

Shut the fuel off to the carb completely and drain the bowl. Then purge the combustion chamber of gas with the plug out and full throttle - spin it over about ten times. Then spoon a little gas down the plug hole and with full throttle, no choke see if it will fire and try to start. You may have something messed up in the carb. This will bypass the carburetor.

 

Still not starting!!!! Seems to me that if I have spark and fuel, that only leaves compression?

flyguy

 

Well as a rule, yes, but there are a number of variables that squelch the starting even though you have the other. Timing, as in flywheel key. Weak spark - although you have a spark at the plug outside the engine it may not be enough to spark in a compressed air environment. May be a bad coil.

A totally flooded engine. Purging it adequately is a key to get it to fire, but it may take a few times over to get the gas residue out of it. All the fuel going to the engine has to be cut off.

A bad spark plug.

 

If the plugs are wet, that is not a good thing like you seem to think. It indicates the engine has flooded, which is what I was beginning to suspect.

 

Cheese and Marjobj:

I cannot believe it!!! It is running!!!

It was the Champion plugs. Even though they showed spark when out and grounded they still would not allow the engine to fire. I finally took them out, thoroughly cleaned, purged the system again and it started!!! The plugs were new this spring.

So I purchased NGK plugs and it starts first time over hot or cold. I will not use Champion again as the counter people at the auto parts house said nobody with any repair experience will buy them, other then us retail customers. According to them the only oem using them is Chrysler.

Chalk this one up to experience.

I sure thank you two for pointing me in the right direction!!! You all were the ones that were persistent in your directions. Thanks again!!

flyguy

 

Glad you got it going. Actually I prefer Champion to NGK, but it doesn't matter... you got it going. Briggs and Stratton AND Kohler use Champion plugs as OEM.