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Hey guys,

I have a Craftsman Eager-1 Tecumseh 6.75hp lawn mower that won't stay running. The carburetor has the plastic bowl, which I have replaced twice. After not having any luck I replaced the entire carb still with no luck.

What the mower does is I pump the primer button & pull the cable. The mower starts & stalls. It also seems a bit hard to pull to start. I have changed the oil, replaced the blade, new spark plug, new carb, rubber fuel line, air filter, and new head gasket but still no luck. I checked out the crankshaft key but it doesn't look damaged.

I was thinking it could possibly be a bad ignition coil but not sure. Don't wanna replace anything else without knowing it'll help. Occasionally after tying to get it running the engine will run but when you go in to grass that is about medium height it bogs down big time.

Any ideas as to what it can be?

It sounds like a lack of fuel problem to me. Is your tank clean and your fuel new? If you've gone through a couple of carbs to no avail, you may have some fuel quality issues. A 13.00 spark checker may be in your future as well, but I think you've still got a fuel delivery issue.

benski said:

It sounds like a lack of fuel problem to me. Is your tank clean and your fuel new? If you've gone through a couple of carbs to no avail, you may have some fuel quality issues. A 13.00 spark checker may be in your future as well, but I think you've still got a fuel delivery issue.

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That's what I was thinking too so I made sure the tank was good & clean & bought fresh gas for it but still no luck. I failed to mention that I checked the spark & it is sparking. I can hear it & when someone pulls the crank while I watch it looks a bright blue/white in color. Is there supposed to be a filter screen or something in the tank? There does not appear to be but I thought there would be one.

As an afterthought could the muffler be restricted & choking out the engine?

Did you check valve clearances? You say it's hard to pull over. thats where I would look

OTWLAWNMOWERMAN said:

Did you check valve clearances? You say it's hard to pull over. thats where I would look

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No I haven't. What's the best way to do this?

Yes, it is quite hard to pull over but not all the time. Oddly enough when there is no gas in the engine it is pretty easy to pull over but when I gas it up the mower becomes difficult to pull over.

Another thing I forgot to mention is when I finally can get the engine running it's a rough running. The engine seems to misfire & engine speed isn't too smooth but goes up & down a little bit.

Plastic bowl carbs need to have an updated fuel nozzle and this nozzle must be seated properly for this carb to work properly. If you have had both carbs apart, you will have to have a pro check to see if they have the update and the nozzle is seated right. Sorry I can't remember which color nozzle is the updated one. Check with your local repair shop and if they are any good, they will know about this update and be able to help you.

Rivets said:

Plastic bowl carbs need to have an updated fuel nozzle and this nozzle must be seated properly for this carb to work properly. If you have had both carbs apart, you will have to have a pro check to see if they have the update and the nozzle is seated right. Sorry I can't remember which color nozzle is the updated one. Check with your local repair shop and if they are any good, they will know about this update and be able to help you.

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So would I have to take apart the new carb to seat the nozzle? When I bought the replacement carb I installed it right on the engine without tearing it apart.

That is a tough question to answer. I have not worked on one of these carbs in over a year and my memory is not as good as it should be. Tried to find the bulletin on this today, but didn't have much time. Going to contact another tech on this forum and see if his memory is better than mine. Don't tear it apart yet, if you can wait and I'll work on a better answer.

The running problem sounds like a fuel issue, but the OP hinted to something that makes me think we could have a compression problem. The OP said he replaced the head gasket, what did the cylinder walls look like. Any deep scratches, or gouges. If possible could you get a compression reading. It would narrow down the possibly causes for the running issue.

I will check for bulletins tomorrow to help out Rivets, since he couldn't find the bulletin. Seems like that bulletins came out several years ago, like early 2000's

ILENGINE said:

The running problem sounds like a fuel issue, but the OP hinted to something that makes me think we could have a compression problem. The OP said he replaced the head gasket, what did the cylinder walls look like. Any deep scratches, or gouges. If possible could you get a compression reading. It would narrow down the possibly causes for the running issue.

I will check for bulletins tomorrow to help out Rivets, since he couldn't find the bulletin. Seems like that bulletins came out several years ago, like early 2000's

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There were no scratches or gouges in the cylinder walls. I noticed the head bolts didn't seem too tight & that there was quite a bit of carbon & oil around one of the head bolts so for good measure I went ahead & replaced the gasket to eliminate that as an issue. The cylinder walls actually looked in good shape for a 15 year old lawn mower engine. What should the compression be and what would be the best way to check compression?

The only way to accurately check compression is with a compression gauge. Compression should be 90 or above.

ILENGINE said:

The only way to accurately check compression is with a compression gauge. Compression should be 90 or above.

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OK Thanks. I have that at home so I'll check it & post the results.

I'm watching this one as I have the same exact motor and problem. Was mowing one day and it just died. Pull cord and nothing. Hit primer bulb a couple times and fired up and just died. Mower is old and needs replacing anyways but am curious as to what causes this.

Gave up on this engine. Found a non-vector 6.75 HP mower & decided to fix it instead of fighting with the vector. That mower is not a self propelled so I'm gonna take that engine & put it on this mower.