No water flow wot trimed up

[CHUCKYZ123]

73 30hp 305ha on 14' skiff new impeller & impeller housing looks ok, no thermostat, new headgasket. cools perfectly when trimed all the way down I can run wot all day but speed is low because not trimed for boat. As soon as I trim up one notch and run wot water flow stops engine overheats. I have looked at manual is there supposed to be a gasket under the impeller plate? If so would this cause this condition?<br /><br />thx for any assist.

 

[CHUCKYZ123]

Re: No water flow wot trimed up

That is there is not a gasket on the impeller wear plate now, should there be?

 

[scotiany]

Re: No water flow wot trimed up

I remember reading in one of my Chrysler manuals that running engine without thermostat WILL cause it to overheat. If you don't overheat at low speed, your impeller might be OK.

 

[CHUCKYZ123]

Re: No water flow wot trimed up

I put a thermo in it and it still overheated at wot with trim up

 

[rsharer]

Re: No water flow wot trimed up

i was told that at wot the impellar fins will colaps if the rpms are to high.my 35 does the same thing at wot.if i back off a few rpms the flow increases.i assume your refering to the flow coming out the tell-tale spout.<br /> i also read that cavitation causes the water going into the intake to "boil",so instead of pumping water,your pumping steam.for your case i would look at this possibilty.trim changes your condition.if your not trimmed to your boat it might cause cavitation.i beleive this is the correct word for it.hopefully someone with more knowledge on this will jump in.

 

[scotiany]

Re: No water flow wot trimed up

Remember, at WOT the water is force fed into your cooling system. The impeller is not as critical as in low speed operation. If your trim is not allowing the necessary water to be scooped up, then you should change your tilt or consider an extension to your LU. You could also have a defective overheat indicating system. The Seloc manual gives specific tests to determine if yours is good or bad.

 

[CHUCKYZ123]

Re: No water flow wot trimed up

Just a thought but the guy who had this motor before put a hydrofoil on it. does anyone think this would cause a problem for water intake?