2003 Suzuki 150DT overheating... assistance/suggestions appreciated

hello all,

I recently purchased a Crestliner fishhawk with a 2003 suzuki 150dt;
Upon the maiden voyage, the motor temp alarm began sounding, the motor was peeing a small stream, upon further investigation I found that once the motor heats up it is supposed to discharge water from the rear of the motor also. It is not doing this and thus is overheating when it reaches that magic temp.

I have checked both thermostats and they both pop open around 130/140 degrees;

Because the peeing stream is obvious, I am assuming that the impeller is working accordingly (perhaps a bad assumption).

Any ideas will be greatly appreciated!

Tim.

Re: 2003 Suzuki 150DT overheating... assistance/suggestions appreciated

Have you tried flushing out the cooling system using the connector on the port side of the motor? Sea weed and sand can build up and clog cooling ports/passages pretty easily. The overflow port on the back of my motor only spills water out at RPM's higher than idle. There's a spring loaded valve below the bottom cylinder on the starboard side of the engine block that allows the extra water to come out at these higher RPM's. I'd look to the clog or the impeller not working under load or higher RPM's.

Re: 2003 Suzuki 150DT overheating... assistance/suggestions appreciated

Great Idea, I saw the flushing connector last night, and slated some time for this evening. I'll have to pick up or make a connector; I also ordered an impeller kit this AM, I figure that its probably not helping any, so it would be better to replace it.

You mentioned a spring loaded valve on the starboard side, below the bottom cylinder, can you speak more to that end? How can one check that it is functioning correctly?, any other tips on making certain that piece of hardware is working correctly?

Thanks much for you input!

Re: 2003 Suzuki 150DT overheating... assistance/suggestions appreciated

The valve I was talking about is in a thermostat housing looking contraption below the starboard cylinder head. There's three bolts that hold the cap on and it's pretty hard contorting your fingers and tools to get them out and back in. Don't know if the moderators are going to nuke my link, but it's number 14,15,16,17,18 on the link below. I replaced the spring and valve on mine but the original looked fine. The valve is just a plastic plug that the water pressure pushes out when the RPMs rise. If you take it apart, make sure you have the gasket that seals the cap on hand since it'll definitely rip and then spray water every where on reassembly.

http://store.brownspoint.com/dt150/fig003-1509803.asp

Re: 2003 Suzuki 150DT overheating... assistance/suggestions appreciated

Okay, I think I am smelling what your putting down, I'll order that from brownspoint also. I should be getting the impeller kit soon, prop shows up tomorrow.

I did hook up the hose to the flush nozzle; the water basically spit out exactly where it does when the ear muffs are on. I expected to see water exit from the rear part of the motor but that didn't happen... is that odd?

I'll keep this thread posted as to the progress and hopefully the solution to the overheating 150 dt.

Once again thanks for your input!

Re: 2003 Suzuki 150DT overheating... assistance/suggestions appreciated

I wouldn't consider it odd since if your water pressure on the hose isn't high enough, it won't compress that spring and come out the over flow. I would imagine replacing the impeller will cure your ills. I replaced mine last summer. The new impeller was much more rigid and the pee stream got stronger. I never had over heating problems, but just replaced it in case.

Re: 2003 Suzuki 150DT overheating... assistance/suggestions appreciated

Update for the post

I replaced the impeller and the prop; of interest is the fact that the original impeller looked like it was brand new... , started the motor and the motor overheated again, I do have the spring valve regulator on order and it should be arriving early next week.

I will continue to update this post.

thanks for all those that are posting.

Re: 2003 Suzuki 150DT overheating... assistance/suggestions appreciated

Also wanted to mention that the pee stream with the new impeller installed seemed aweful weak. Not sure why; possibly over-analyzing this issue. I expected to get a very strong stream from the new kit. My last hope is to get the spring valve water requlator replaced and hopefully that will fix the issue overheating issue.

What temp should the thermostats open up at? When I tested them they began to pop open at 130-140 degrees; I think that is normal but it may not be; whats your take on that?

Thanks Tcrum5711

Re: 2003 Suzuki 150DT overheating... assistance/suggestions appreciated

I would have figured the new impeller kit would have fixed the problem. Did you try the flush port with the t-stats out to see if water was getting to the top of the heads? Your garden hose should have enough pressure to push water up there. How does your spark plugs color look? Any white or milky gunk on them?

Re: 2003 Suzuki 150DT overheating... assistance/suggestions appreciated

I removed the t-stats and plugged in the house to flush out the system., I could feel and hear the water pressure in the little hoses that run up and over the top of the cylinder heads, but couldn't feelany water pressure in the two long rubber tubes that run vertical on each head.

I did pop off the water spring valve and pumped water through the flushing system, water did flow up and of the bottom hole, the spring seemed a little stiff but not overly so.

I then left the spring and plug out along with the t-stats and put the muffs on and ran the motor, still no luck... so I replaced the spring valve along with the t-stats... then it was bed time for the little fisherman in the family, couldn't test.

the fact that the two vertical rubber houses don't fill with water is disturbing, any hints on the next step I should take?

Also, i didn't pull the plugs yet, will let you know tomorrow night.

Thanks

Re: 2003 Suzuki 150DT overheating... assistance/suggestions appreciated

I'd pull one end of the vertical rubber hoses off to see if it'll pump water out of those first. How hot is the pee stream when the alarm goes off? If it isn't steaming or hot on your hand maybe the temp sensor is acting up?

Re: 2003 Suzuki 150DT overheating... assistance/suggestions appreciated

Took out the boat last night; wanted to conduct a 'real' test... (and get some fishin in). The motor seemed to work correctly! No overheating, spitting water out the back, pee stream strong... I would guess that the new impeller didn't hinder the progress any.

It probably didn't hurt to pull out the water valve t-stats to double check and apply supper light coat of oil. I also had a new prop installed after the impeller had been replaced. One thing I will say is that the new prop is letting the motor breath much better, I can almost stick my hand between the hub and the outer wall of the prop in three different places. Whereas with the old prop, one would be hard-pressed to find a hole big enough to put a phillips head screw driver through...


I spoke with Tiger Marine (New London, MN) yesterday evening and he cautioned that ear muffs and the garden house don't always have enough water pressure, therefore the water pump doesn't get primed... he stated that the boat motor needs to be tested in the water!

Thanks a bunch for all your input, hope this thread will assist others.

Thanks Tcrum5711; hope to see you on the water!

Re: 2003 Suzuki 150DT overheating... assistance/suggestions appreciated

Glad it was something easy. I've never had a problem running on muffs in the drive way. Bought a better set and I have city water. Must help out enough in the pressure department.
The original prop that came with my boat had the same large hub that didn't allow the motor to breathe either. It's amazing what a SS prop and free flowing exhaust will do for a motor.