having trouble with my MB 35. yesterday we had been running for about 30-45 minutes i throttled down and put it in neutral. as soon as i did this the motor cut out. couldnt get it started again. fuel is fine, battery is fine, oil is fine. No spark though. I am thinking it may be a faulty kill switch. Anyone have any advice?

the oil pressure switch by the oil filter has a green wire on it. If you have no pressure, you'll have no spark, It grounds the ignition. Try pulling the wire off, and see if you have spark.may be faulty. (but don't run without switch, may destroy the engine) Also where the green wire goes into the shroud, by the oil cooler,may have rubbed through the wire.2nd, check the wrist strap, it also kills the engine, may be shorted. you can get a schematic (wirin diagram) on (shhhh!! quiet!) (mb site)oh shi@t did I write that??? I may git tarred and feathered from des boys for that!!! ha ha, it may be under customer page It's prolly sumtin simple, just a damb mower engine!! hope this helps, let me know!!

gcat, I looked at the schematic, the green wire from the oil pressure ties into the green wire on the kill switch,lanyard, they go to the connector block, probably under the black plastic cover,and tie in with the black wire on the key switch. these ground the coils. from that 8 wire harness, 2 wires, black and brown go to the coils. If you unhook that 2 wire plug, that should bypass everything, and you should have spark. good luck!

thanks for the help. gonna go give it a try. it was a fun 4 hour paddling session last night. could have been worse. we had the wind at our backs and the thunderstorm did hold out til we got back to the truck.

Ok, turns out after checking everything there was a short in the spark plug wire. Motor starts and sounds great, but got it out on the water today and wouldn't push the boat worth a darn. Went from running 22 mph with full load before these problems started to going 9mph with just me and some gear.

I changed the spark plugs and wiring yesterday so could this effect the Motor like that. I am still getting 3800-3850 rpms at full throttle. The motor just isn't pushing the boat.

Pull each plug wire while running to see if you got a dead cylinder. You could have a bad coil.

So even with a dead cylinder I would have a smooth running engine with good rpms? Excuse my ignorance. By the way, love ur avatar!!

Without a load yeah, but it would bog down when you put it in the water. You getting full rpm's with a load on it?

Yes it is getting full rpms with the load. I just don't get it.

That's weird. Now it sounds like a setup issue, like it ain't getting good water or like you are dragging something. Did you change your trim setting or anything? I watched a guy down the road think his sht was jacked up, ran full throttle all the way back going like 5mph, he forgot to pull his anchor in.

Is your clutch slipping? If it still turns up but you aint moving either your prop is shot or your clutch is slipping.

Your rpms will look good with one cylinder because the tach is picking up off of one plug wire,thats if its on the good one.Just went through that same thing with a 40 kohler,4 hours and a bad coil.

Could be your diode. It would cause it to run on one cylinder and they are easy to fry if you are in there messing around with things.

So how do I figure out it if it is a diode or if it is running on a single cylinder?

Start the motor then go to a spark plug wire and pull it,if you do not feel a shock and the motor runs the same without the wire on the plug you are not firing on that cylinder.Or you could pull the plug and leave the wire on it and crank the motor to check for spark.