200 EFI Mariner Over heating

[SkiThEast]

Ok guys here is my problem maybe someone out there can point me in the right direction.

I have a 200 hp Marnier EFI that is getting real hot if I run anything over 2000 rpms

So far I have put a new impeller in it, ran it with out the t-stats, and flushed the system to check for blockage. All of witch did not correct it Ran it with the cale off and saw no seapage around the heads.

The flow of water through the engine seems very consistant regardless of the rpm range and the engine cools down with or without the T-stats in it when you bring it back to an idle.

Input would be much apprecitaed

 

[Faztbullet]

Re: 200 EFI Mariner Over heating

Did it just suddenly start this or did you have a impeller failure??

 

[SkiThEast]

Re: 200 EFI Mariner Over heating

Just purchased the boat of a good freind that had not had this problem.

The impeller did not look bad, but I replaced as i thought it to be the weak link.

Someone else told me it could be the head gasket aroung the water jackets.

 

[j_martin]

Re: 200 EFI Mariner Over heating

Check the poppit valve on the starboard side. Could be plugged up. The exit from the poppit is a hole, triangular as I remember it, that goes downward to the base.

It's supposed to open up at about 2 grand or so and allow more cooling water to flow.

A pressure gauge would help. Symptoms of a failed poppit would be excessive pressure.

hope it helps
John

 

[SkiThEast]

Re: 200 EFI Mariner Over heating

Thanks John,

That is the first someone has thougt it was the poppit valve

I have a Climber manual, I'll read up on that tonight and post my findings.

 

[j_martin]

Re: 200 EFI Mariner Over heating

When you idle it on the cuffs, it should pee a little, maybe intermittently if the water's pretty cold, and also there should be a little flow out the prop. If you rap it (briefly, and not over about 3 grand) you should get a noticable amount more out of the prop.

A pressure gauge would help you diagnose the system.

hope it helps
John

 

[SkiThEast]

Re: 200 EFI Mariner Over heating

I pulled the hose off the fitting at the top of the block that leads down to the poppet valve. Blew through tube and there seemed to be little resistance. I did not have the time to pull the plate off at the base of the block.

Water flow out the pee hole and out hub of the prop is exactly how you described it.

I have a buddy with a pressure gauge, but I willn't be able to get the boat to him for about a week.

This one has me scratching my head!

Thanks for the help

 

[jerryjerry05]

Re: 200 EFI Mariner Over heating

If your running it on the muffs you might not be getting enough water.Jerry

 

[SkiThEast]

Re: 200 EFI Mariner Over heating

I have only run it on muffs twice since purchasing it. The same problem has occurred 4 different times on the water.

1st when the problem was discovered
2nd after I took the thermostats out
3rd after I replaced the impeller with the thermostats still out
4th put the thermostats back in with the new impeller (didn't think it was getting enough back pressure)