Runs great but starts hard

[wapacz]

My friend just picked up a lawn mower with a 18 hp Tecumseh engine. This engine is a bear to start after its cooled off. If you shoot a bit of start fluid in the intake it starts right up. If you turn the motor off it will restart while it is warm though to me it takes a few more cranks than a warm engine should. The weird thing to me at least is that once the engine is running it runs great.

I already checked the choke on it and it close off the passage way by like 3/4 so it appears to be working right.

So do any of you guys have any idea what be causing this problem.

 

[tomcat27]

the carburetor needs to be removed and cleaned. perhaps the choke needs to close a little more?

 

[JTK]

You don't see an awful lot of the larger OHV Tecumsehs. Given it will fire when you richen it up, it does indicate a fuel/carb related concern. Like tomcat says, a possible carb cleaning is in order, or it could be a weak fuel pump, plugged gas cap vent, etc.

 

[wapacz]

Yep it looks just like that picture you have there.

 

[Pete591]

When valves get out of adjustment ...one of the first signs is the engine is hard to start.

Check them and adjust if need be.

 

[wapacz]

Originally Posted By: Pete591
When valves get out of adjustment ...one of the first signs is the engine is hard to start.

Check them and adjust if need be.



How long does that take to happen usually. This engine has under 200 hours on it and is 5 years old.

 

[Pete591]

Originally Posted By: wapacz
Originally Posted By: Pete591
When valves get out of adjustment ...one of the first signs is the engine is hard to start.

Check them and adjust if need be.



How long does that take to happen usually. This engine has under 200 hours on it and is 5 years old.


They say to check and adjust yearly....you are overdue.

 

[roadrunner1]

new spark plug can't hurt

 

[JTK]

Maybe I'm lucky, but I've never seen an out of adjustment valve related issue on an OHV OPE engine. Probably 99% of them in residential use are never even checked.

Joel

 

[greenaccord02]

Originally Posted By: tomcat27
the carburetor needs to be removed and cleaned. perhaps the choke needs to close a little more?


This is exactly what I was going to say.

 

[Mamala Bay]

I'd look at the spark plug first. A dirty plug will give a weaker spark. Also plug might need replacement.

If problem still persist than I would be looking to clean the carb out.

 

[wander2039]

I'm not sure if yours have the same issue but I'd check the cotter key on the flywheel. That is if you do all the above and you still have the problem. Had a Tec. 6.75 that sheared the key at only 3 years old, been setting for four years since then all from a .50 part! I guess with Tec. this is common problem.

 

[wapacz]

yeah spark plug and oil change is in the list of things to do to the mower.

 

[Jaymus]

I'm thinking valves out of adjustment, also.

 

[Mamala Bay]

Small engines with valve problems are usually manufacture defects, alignment problems.Some may show up after so many hours. Valves that are in need of an adjustment would have a missing rough sound from the engine. Broken valves engine will not start in most cases.


The problem sounds like it's the spark plug. If engine is hot it could also mean the ignition coil isn't putting enough current to the spark plug. If this is the case more times or not it's a sign the ignition coil could be going bad. It could be a problem but I would check the spark when the problems occur. Most times it's a dirty spark plug that needs cleaning or a plug that needs to be replace.

 

[JimPghPA]

The first thing I would check is the gas. Take the cap off and if it is old enough to not smell like gas it is no longer good gas. I like to have gas so fresh that if I open the cap on the front porch people in the house complain.

If the gas does not smell like gas get all of it out out of the machine, and put fresh gas in. Try to either drain the carb or start the motor with start fluid to get the old gas out of the carb.

If the gas is fress, I would chect in order, the plug, is the plug wet inside, or ceramic on inside fouled and black? Is the plug a cheap brand or a good brand. Is it the corect plug number at the corect gap? Then I would think about the choke,vaves,carb,and oil.

JimPghPa

 

[JTK]

That is a good call in regards to the fuel being used. The owner might have a whole 5gal storage can of khrap gas he's dealing with. Once they fire and got hot they *may* be able to tolerate not so good fuel. Given this engine runs perfectly once it gets started I'm still puzzled at all the recommendations here to adjust the valves?? If it runs perfectly once it gets started, how can this be a valve issue?

Joel