Try a new RJ14 plug. I had the same problem! I tried 2 coils.......seriously......Try a different plug.

 

You might want to use a champion CJ14 plug, it is what is recommended for Lawn-Boy.

 

Not for the "V" engines. They used a Champion RJ12C. The DuraForce and "V" series were the only Lawn-Boy engines (to the best of my knowledge) that used a different plug than a CJ14. They're gapped at 0.030", not 0.035" like the OMC D-600, "M", and "F" engines.

Interestingly, my boss' 10545 ("F" engine) came with an NGK plug BMR4A, which is a direct cross to a Champion CJ14.
I knew the DuraForce uses an NGK plug, but that one is unique to that engine...It has an extended tip, and there is no perfect cross into Champion for it. NGK BPMR4A crosses to a Champion RCJ8Y, but that plug is several steps colder, though it is of the same design.

I had never seen an "F" engine sporting a factory-installed NGK plug before. I wonder when/why the switchover?

Edit: I think I figured it out...Champion doesn't make a resistor-type CJ14 (RCJ14 would be the part number if it existed, but it doesn't), and possibly they were required to use reisitor plugs in all their engines, so the resistor NGK equivalent was the only logical choice.

 

OOPS, ! I typoed! I meant CJ14, lol. thanks croc

 

No problem Kightrider, it's easy to get the numbers mismatched on these things.:fing32:

 

Well I ended up taking the carb apart in the time between my first post and this one. Adjusted the float level. It now stays running, but it's running kinda low and surging. Not sure if maybe it's too rich now?

 

While you took the carb off did you see the little thumbwheel with ridges under the govenor sail? With your mower running, reach down and give that wheel about 2 clockwise turns to increase it's speed.

EDIT, two clockwise CLICKS, not turns. Sorry about that

 

Two turns or two clicks? Just want to be sure he does not break the spring.

Pete

 

Sorry bout that, two clicks it is :fing32:

 

Just went to try what you suggested and now it won't even fire up. The float must be out of adjustment to where it will only run when it's warm/hot.

 

my 10304 is doing the same thing! I turned the govenor also my wont start either!:crybaby: So i have my carb tore down and havent gotten back to it so i will be watching this thread.:i_praying

 

Ok lets start at the begining. When you had the carb apart, did you replace anything? Did you tear the whoe thing down and start fresh or did you just spray cleaner/air with it all together? On the side under the sticker, there is a screw, did you take that out and clean it? The float needs to be adjusted to 7/16"-15/32". This measurment is taken from the top of the float to the flange of the fuel bowl without the gasket in place. After the float is adjusted, does it stick anywhere in it's travel? If it does, you will need a new needle and seat. Is the choke butterfly opperating correctly? It should be closed when the choke is on. You can adjust the travel of the cable by loosening up the nut and bolt on the air box and sliding the mount in or out and retightening.

Is your fuel system working properly? I know it's gravity fed, but any clogs/kinks in the line? Is your primer bulb cracked or not hooked up properly? Does the vent in the fuel cap work?

Last but not least. Did you remember to put the plug wire back on the spark plug? I know it's a stupid question to ask but, I've done it myself.

Hopefully you can mentally retrace your steps and not have to rip into it again.

Pete

 

That little governor speed increase has to do only with engine speed, so something else may the culprit. Nomad, as long as you have your carb off, check and see if you can see the reeds in your engine. Some people have found a stick or grass in there so it's worth a shot to look. Other than that, it's a fuel or spark issue.

 

Is it strange that this mower does not have a throttle/choke? Only a primer. Just wondering.

 

I have two 10301s and they both have a handlebar-mounted throttle. I never use it, but it's there. There is no choke, only a primer bulb.
Maybe that's half the problem?
If you don't care about the throttle, just push the speed control slider fully to the right (viewing the carb from the rear of the machine), and secure it in place with a zip tie or perhaps some epoxy for a permanent single speed operation. Set your speed to 3200 RPM and you're set.
The throttle on the 10301 is cheaply built at best, and both of mine are set and locked (I just tightened the mounting screw tighter) to their fast position.

 

I didn't know about the spark plug thing in the V's and The duraforces, but since they aren't actually made by OMC that doesn't surprise me. I do run a CJ14 in my dura anyways, and I know a few others that do to. Kev, it is strange that your mower has no throttle/choke lever as most of them did. Does yours have the little plastic tab throttle found on the carb itself?

 

The original gas tank/shroud was cracked, so the previous owner threw it away and rigged another fuel tank to the mower along with a piece of metal to fasten it down. Here is a picture to show you what I mean:

There is a flimsy metal switch down there that seems to have 2 positions, much like the older LB's with their fast/slow switch down on the engine.

 

Yes you need part number 93-7734 or rig up your own as it is fairly expensive from the dealer.

Pete

 

The plastic tab throttle Croc is referring to is #3 in the parts breakdown above.

Pete

 

I have the correct gas tank that I'd be willing to sell if you're interested. I don't have a decent throttle control though. That looks like a decent machine...I'd fix it up and make it nice!

PM me if you're interested. I'd take a reasonable offer on them.

I actually have a nearly whole 10201 that I'm parting out, so anything else you can think of, I might have too. The 10201 was the push version of your machine, so no self-propelled stuff.

 

Would this wheel underneath the governor sail have any effect on the mower if it is not running?

 

No, but once you start the mower up it may run faster. If you click it too much clockwise it might unwind and then you have to click it around some more to wind it up.

 

OK my 10304 carb was spotless! put it all back together. put fuel in primed pulled cord and it started and then died! cant get the darn thing started> prime again starts and dies! this only started after i messed with the govenor? im so freaking confused. the ports were clean!:banghead3 also i took the blade off to have sharpened before all this to would this affect it.:1336:

 

So I've got an update on my problem.

Long story short:

New carb from another mower, complete with throttle. Cleaned spotless.
New shroud and tank.

Mower looks great.

Fire it up, same problem. Gets hot and shuts down.

Could it be exhaust ports plugged up?

 

Sounds like these two are starving for fuel.

If you have checked the exhaust ports and theyre clean, and you say you have run a tag wire through the small carb passages to make sure that there isnt any crud in the jets, the next place to check is that rinky dink filter that is in the fuel line on the Silver Series. I believe the last year that the Silver Series were made, Lawnboy had finally received EPA certification for their fixed jet nylon carb, but the filter was applicable to that carb too. This is why some of the SS come with Walbro carbs and others with traditional lawnboy nylon carbs.

The filter is in the fuel line where the line meets the carb. Its a steel mesh filter with a brass lip. When you find it, ditch it and install a regular in line filter. Any ethanol gas that has even a little water in it will cause the filter to rust. Even if you drained the fuel at the end of last season, the humidity in the air will rust that little gem.

Had a friend ruin a really sweet big Poulan 655BP saw from water in the gas can from the Ethanol gas. Apparently his two cycle gas can had sat out in the garage all winter and collected water out of the air. He needed to take down a good sized tree on his property and gassed the saw out of that can. When the saw started running funny and then shut down, the damage had already been done. He dumped the saw's gas tank into a clear basin to look at the fuel and found water at the bottom. He then dumped the remainder that was in the can and found more water.

This problem is called phase separation. Gasoline was invented so that no water could mix with it. Nowadays because ethanol is added to gasoline, when water comes into contact with the ethanol portion of the gas it is absorbed. When the water comes in contact with the oil that is added into the mix for a two cycle, the oil will not mix with the water solution. The saw engine is toast because the engine received gas but no oil and the cylinder and piston are now scored.

Please do yourselves a favor and dump the old mix can into the tractor or your pickup and mix fresh fuel for your two strokes. Keep the mix can capped and out of the sun. Only mix what you will use in a months time.

Best wishes,
Bob

 

I used a different fuel line with each carburetor, so I'm not sure that's the problem, but I will check to be sure. What are the symptoms of plugged exhaust ports?