overheating prolbem

[90sunbird]

have a 90 sunbird 3.0 with omc cobra overheats at idle with earmuffs on looses prime cant see any air gettin sucked in when water hets in to head cools temp but gos right back up. it gets water in spurts did have impeller brake apart an changed new gasket and pump any sugestions p.s. does not overheat on water

 

[flargin]

Re: overheating prolbem

have a 90 sunbird 3.0 with omc cobra overheats at idle with earmuffs on looses prime cant see any air gettin sucked in when water hets in to head cools temp but gos right back up. it gets water in spurts did have impeller brake apart an changed new gasket and pump any sugestions p.s. does not overheat on water

did you get all of the pieces of the impeller out of your system when you replaced the last impeller. Don't know the cobra, but with mine, the impeller bits plugged up against the oil/PS coolers.

If not, That may be a good place to start.

p.s. does not overheat on water

This would make sense since it has a lot more power at throttle.

 

[flargin]

Re: overheating prolbem

BTW, welcome to the forums...

 

[90sunbird]

Re: overheating prolbem

thanks looks to be a very good fourm, lots of people i will give you a background on what i did to this boat, removed head installed 1.94 1.60 valves cut .40 off the head raised compression about .75 of a point installed bigger cam wich had to be coustm ground for only 100 bucks and rodes lifters due to the bigger valve and cam also ported and polished head chambers hoping to get about 35 to 40 more h.p. on top of the stock 130 found ne leaks or crackes in head. boat runs very good 45mph at 4500 with a 14.25 21 pitch prop. the boat will not overheat with the hose hooked up directly to the engine intake port but with earmuffs the water takes to long to get to the engine intake and when it does get there it spurts out then looses prime i have cleared all the water chanals in drive from the old impeller as far as i can see i just cant seem to get a steaty stream of water up to the engine??? but when on the water i have no prolbem less force rquired to get to motor i think but im stumped any help is greatfull thanks oh ya no power stearing in this boat

 

[Bry21317]

Re: overheating prolbem

This is Just a guess, but I had the same type of problem in the past.

What mine was, was the impeller housing was tightened to tight on my Alpha drive and it was leaking on the Muffs, but when in the water it had water all surrounding it and it would no longer leak.

Once I ifigured this out, which was a nightmare to find, I was able to get mine working right.

Hope this helps or at least gives you something to look at.

Bryan

 

[90sunbird]

Re: overheating prolbem

yes ive ben there but fourtanally i have a cobra outdrive and i dont have to dissimble the lower unit it is conventally on the outside of the case i also cleaned the gaskets and replaced the pump no leaks bot thanks for the advice i will double check it!!

 

[90sunbird]

Re: overheating prolbem

i think i found my prolbem the outdrive impeller housing fingers spun inside the housing about 3/4 of a inch causing a restriction in the outlet will test tomarow and post if it is fixed p.s. did this ever happen to anyone