Head Gaskets and Water Deflectors

[GatorMike]

I've been posting about my crossflow 115 rebuild. Got it running last night but had to adjust the idle down a bit so only ran a couple of minutes. Tonight I had my son start it while I kept an eye on things. He ran it about 5 minutes then quickly shut it down. I asked him why he shut it down and he said he heard the overheat buzzer sound. I then touched the cylinders and they seemed a little hot. The only thing I didn't replace when I rebuilt it was the water deflectors because they were not shiped with my parts and I was in a hurry. I knew they could be replaced at any time so I took a chance. My question is, I am going to replace them tomorrow after work. When I remove the heads can I reuse the new head gaskets I just put in or do I need to replace them since they have been torqued down on?

 

[walleyehed]

Re: Head Gaskets and Water Deflectors

head gasket should be replaced everytime you remove a head, or loosen the bolts.

 

[rodbolt]

Re: Head Gaskets and Water Deflectors

did you change the t-stats? if so what brand did you buy?

 

[OBJ]

Re: Head Gaskets and Water Deflectors

You'll need to replace the head gaskets Gator. Once torqued and the metal rims are squished, chances are they won't seal again.

 

[GatorMike]

Re: Head Gaskets and Water Deflectors

Rodbolt yes I changed the T-stats, not sure the brand got them from an omc marina though.<br /><br />I'm only assuming she is running hot. I did a real scientific test. I could touch the cylinders about 1 second before having to remove my fingers. So I heated a cup of coffee in the microwave to the temprature where I could touch it for about a second then used the wifes baking thermometer to measure the temp. Was about 170 degrees.

 

[rodbolt]

Re: Head Gaskets and Water Deflectors

if you used the original OMC stainless type t-stats and did not vent them they will give fits on the flusher. I now use the sierra part number for OMC crossflow motors. the t-stats are no longer vented from OMC/Bombardia and the heads heat up before the hot water has a chance to open the t-stats. its common. customer will say I start it and it overheats in less than 5 min at idle, turn it off let it sit ten min and its fine. next time its heating up touch the t-stat housing and see if its as hot as the top of the head. if its not your t-stats have not opened. if I use the stainless t-stats I use a dremmel and cut a vent notch in them.<br /> good luck and keep us posted

 

[walleyehed]

Re: Head Gaskets and Water Deflectors

18-3673 is the Sierra P/N...

 

[rodbolt]

Re: Head Gaskets and Water Deflectors

walleyehed<br /> you ever have that problem on the crossflows?

 

[OBJ]

Re: Head Gaskets and Water Deflectors

Rodbolt...can you expand on the venting thing a little???? Dummy here (me) is a little in the dark about the venting thing. Thanks.

 

[rodbolt]

Re: Head Gaskets and Water Deflectors

OBJ<br /> years ago the original t-stats had a tiny slot cut in the poppet valve to allow a small amount of water to by pass the t-stat to allow the hot water to get to the t-stat as hot water does not like to go down it wants to go up. the newer style stainless ones you buy from the dealer had the slot eliminated which worked ok for the little motors and the v-6 motors but not worth a poot on the crossflow motors. I wedge the new style valve open and cut a tiny slit with a dremmel or I use the sierra part that is self flusing and has the vent. does that help any ?<br /> good luck and keep posting

 

[OBJ]

Re: Head Gaskets and Water Deflectors

Thanks for the info rodbolt....I'll definetly take a look at that. That might explain a couple things that happened to me when me and my Dad was fishin'. We was putting around an area of water trying to find a hump we like and the horn went off. This happened a couple times. Check the water intake and all. Leave it off for a few minutes and kick her over and all is well. I do appreciate the info. I'll let ya' know what I find.

 

[DJ]

Re: Head Gaskets and Water Deflectors

I have experienced the initial overheat after stat replacement on crossflows. Scares the bejeebers out of you! Not to mention embarrassing. <br /><br />I noticed it when I compared the originals to replacement OMC's. It took me about about a half hour to figure out why they didn't look the same-duh. I changed the new ones by grinding a tiny slot on the outside rim. Worked good!

 

[walleyehed]

Re: Head Gaskets and Water Deflectors

Rodbolt, yea, I have ran accross this, and like you, if I have a T-stat with no vent, it gets one. Just a slight slit is all it takes!

 

[GatorMike]

Re: Head Gaskets and Water Deflectors

A couple of questions about this T-stat situation. I took it to a friend of a friend who used to be an OMC mechanic tonight and let him check it over and make a few adjustments. It's running much better now. It didn't have the problem of getting hot like it did last night. The mechanic said it did feel a little warmer than he felt it should but he didn't have a thermomelt stick to check it with. I told him that last night it got much hotter after just 3 or 4 minuits than it got tonight when it ran a half an hour. He said the new thermostats may have been stuck and finaly opened. I guess what I want to ask is this something I need to worry about? Do I need to take those T-stats out and slot them? (not an easy job at this point) Sunday when I take her out on the lagoon for a test ride are there any precautions I should take?

 

[rodbolt]

Re: Head Gaskets and Water Deflectors

gatormike<br /> if you know they may be sticking start the engine let it idle 3 or 4 minutes then shut it down for a few minutes to let the hot water in the heads settle to the t-stat housing. then restart it and odds are it will be fine.<br /> good luck and keep posting