2006 merc 40 4 stroke

[racerone]

Squirt some oil into the intake or mix some oil with small sample of gas.----The smoke will make it easy to find a leak.

 

[Mohawkmtrs]

Bingo!
I had an older Honda in the shop with the very same symtoms.
Turned out the exhaust manifold had a hole burned through...Too bad the part was NLA and was not financially feasible to remove the powerhead.

 

[longeze]

Squirt some oil into the intake or mix some oil with small sample of gas.----The smoke will make it easy to find a leak.

I'll give it a shot. I put the thermostat in hot water again and it opened at 160-170. Could that do it? It's a 140deg thermostat. I ordered one anyway. Thanks for the advice!

 

[longeze]

I'll give it a shot. I put the thermostat in hot water again and it opened at 160-170. Could that do it? It's a 140deg thermostat. I ordered one anyway. Thanks for the advice!

I changed the thermostat and still not the fix. I took off the high pressure pump and the screen was covered in small particles. Cleaned the screen. I took out the rubber plug the pump slides into and found this? It was in the hole just laying in there? Does it go in the pump? The Schrader valve is on the side of the hole. I can't figure out where it goes other then it fell out of the pump. I ordered a new pump.
Lol

 

[longeze]

I changed the thermostat and still not the fix. I took off the high pressure pump and the screen was covered in small particles. Cleaned the screen. I took out the rubber plug the pump slides into and found this? It was in the hole just laying in there? Does it go in the pump? The Schrader valve is on the side of the hole. I can't figure out where it goes other then it fell out of the pump. I ordered a new pump.
Lol

Looks like it fits the tiny hole in the pump intake.

 

[longeze]

Well I took off the lower end and behold the pump gasket was blown out! Replaced it. Also installed the new high pressure pump in the evaporator. Turned the key and the fuel cooler on the side sprayed out fuel. Took it apart and noticed the orings were hard. Went to auto zone bought a small orange kit. Replaced all Owings. Put the cowling on and went for a ride. Yea!! Ran great! Have to laugh but impeller just wasn't doing the job so it would heat up. Thanks everyone for all the great ideas! Great site.