overheat issues suzuki 200 hp 2 stroke

cjrama

Cadet
Joined
May 3, 2009
Messages
18
i have a 2000 200hp 2 stroke motor with a new waterpump. the pee stream varies from very good to drippin out. at trolling speed i get the high temp warning but i can go just fine at cruising speeds. i ad opened up the thermostat housings and the thermostats had opened at temp and cloced after i pored cold h2o on them. I took the new water pump apart when i got home and reassebled it after checking it out and i had a great stream. today i started it up again under same conditions and it was weaker. water coming out hole is generally cold when the heads are hot Any ideas?
 

James R

Commander
Joined
Feb 1, 2007
Messages
2,660
Re: overheat issues suzuki 200 hp 2 stroke

Had a case where the old impeller had come apart. Pieces were blocking the waterways. Sometimes they would clear a little and allow a good flow then block again.
Try this. Remove the thermostats, put the covers back and test the motor for flow. If very good it could be just the thermostats.
Pull the lower unit and check under the pump and in the intake for junk. Make sure that the pump housing and plate are not scored. If they are that may be your problem. Make sure that you rotate the drive shaft clockwise when you press the pump housing over the impeller. If you dont then the blades will be wrong way round and no pumpee water. Leave the lower off and remove the thermostat covers. Use a water hose with a gun and intermittently shoot water up the water tube. See what happens. Then apply a steady flow up the tube and see if water flows without restriction. Shoot water into the thermostat cavities. Water should run freely out of the lower tube. Shoot water up the tell tale spout and see if that flows. This procedure may help dislodge any debris.
Check that the seals are good at the water tube. If all this does not do it then you may have to take the power head off. Debris in the water distribution cavities under the power head may be the issue.
These motors do not generally pump well if using muffs. You need a barrel or a pond.
 

Mas

Lieutenant Commander
Joined
Oct 3, 2006
Messages
1,656
Re: overheat issues suzuki 200 hp 2 stroke

How "hot" are the heads? Can you leave your hand on them for three seconds?

MAS
 

cjrama

Cadet
Joined
May 3, 2009
Messages
18
Re: overheat issues suzuki 200 hp 2 stroke

you can hold your hand to it for the first couple minutes, then it becomes too hot to hold. Water coming out is generally cold. then if i turn off the motor. the remaining water coming out is very hot.
 

Mas

Lieutenant Commander
Joined
Oct 3, 2006
Messages
1,656
Re: overheat issues suzuki 200 hp 2 stroke

At temp, it is diffiicult to hold you hand on the motor for more than three seconds...unless your hands are all callused up.

Get one of those cheap infrared thermometers to check the head temps. It should not read over 160.

MAS
 

mik44

Recruit
Joined
Aug 10, 2008
Messages
3
Re: overheat issues suzuki 200 hp 2 stroke

I have an overheat situation that none of the local mechanics can diagnose. The last one suggested I try running the engine without the T-Stats. Is there a danger in this?
 

Scrapiron

Cadet
Joined
Jul 3, 2009
Messages
17
Re: overheat issues suzuki 200 hp 2 stroke

Mik,
I recently bought a boat w/ the same problem. One mechanic said the same thing...remove the thermostats. After talking to several other techs i decided it probably wasnt a good idea(as a permanent solution). According to them, the thermostats slow the water down allowing it to absorb more heat before it passes through...and that this helps cool better than cold water just rushing through. Sounds backwards to me, but several ppl told me the same thing. One thing though, removing the thermostats and monitoring the water pressure, could tell you if there is a problem w/ the thermostats. As for removing them forever, not sure. If you find out anything else lemme know!

-Scrap
 

James R

Commander
Joined
Feb 1, 2007
Messages
2,660
Re: overheat issues suzuki 200 hp 2 stroke

You need the back pressure created by the thermostats to help fill the water jackets with water. Without them you run the risk of hot spots and engine failure.
 

Eshaw150

Petty Officer 1st Class
Joined
Nov 30, 2008
Messages
295
Re: overheat issues suzuki 200 hp 2 stroke

Removing the tstats also depends on if the motor is carbed or fi if it is carb its not as bad but u still need them in for pressure if it is fi the if the t stats are out the motor runs cool all the time and the cpu will tell it to ad more and more fuel to heat the motor up resulting in a sheen in the water internal damage and huge fuel consumption thermos are verry importantt
!!!!!Look at it like this if they were not need they manufacture would not have wasted the money to design it with them!!!!!
 

JFrink

Recruit
Joined
Aug 8, 2009
Messages
1
Re: overheat issues suzuki 200 hp 2 stroke

I am the owner of twin 200 four strokes. I got an overheat alarm on one engine (good to have two engines - I was out in the ocean seven miles from my inlet) I got to work trying to find the problem: 1st replaced the tstats, then check all the connections. (amazing: on the top of the intake manifold there is an opening, when I compared it to the other engine, that some hole had a factory plug in it - when I started the bad engine water splashed out of the hole, and thus the cause of the corrosion on the bad engine - how did that plug come out?) Anyhow, after new tstats and wiring checks, I still got the alarm. Next step take boat out of water and remove lower unit and check water pump and water pressure valve, both okay but I replaced the impeller because I had it open. Back in the water and still the alarm. Next I unplugged the three temp sensors (two exhaust manifolds and one on head), engine ran fine, plugged in head sensor, no problem, plugged in one manifold, no problem, plugged in second manifold and alarm sounded. I then switched the two manifold sensors and plugged in the one from the good manifold and no alarm, plugged in the sensor that I thought was bad and sure enough the alarm sounded - tomorrow I'll get a new sensor and hope that the problem is finally solved.
 
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