1997 volvo penta cobra sx manifold over heating

[irawalls]

Hello ladies and gentlemen,
I have a 97 crownline with the 5.7 chevy engine with the cobra sx , I purchased this boat a month ago, needless to say i got took... done put all new hoses and thermostats and fuel injectors then a new motor, now since with the new motor right riser gets hot and now left riser is cooking, im tired of throwing good money after bad but needing some help? risers are rusty and corroded on inside and i cleaned them but they need replaceing ,Local shop is no help on information ,but my questions are

1... does this motor exuast from prop...could there be a blocked exuast port in foot? (found one at base of stern)
2... do these lower units have a impeller in the foot ,cant find on any diagram

 

[jerryjerry05]

Re: 1997 volvo penta cobra sx manifold over heating

Need more info? Serial#s Model#s any thing to help identify your setup?
Some exhaust systems have the flapper in the down tube.Newer ones don't.
Does exhaust from the prop.
No impeller in the drive.
It's in the engine compartment.

 

[irawalls]

Re: 1997 volvo penta cobra sx manifold over heating

does have the flapper,in down tube but at work right now and will post the numbers later

 

[dypcdiver]

Re: 1997 volvo penta cobra sx manifold over heating

1) the impeller is mounted on the engine (different models different location hence need for Serial#s Model#s) When old they shed their vanes which then lodge in lots of places, the thermostat bypass passage being one.
2) Make sure the Thermostat housing has clear ports that supply the cooling water to the exhaust manifolds, and that the entrance to the manifold is not blocked.
3) The exhaust and cooling water whilst underway do mainly go out through the centre of the prop, but at idle it comes out of a relief port located above the Anode on the transom shield. In 1999/2000 Volvo/OMC decided that the flappers where not needed.

 

[irawalls]

Re: 1997 volvo penta cobra sx manifold over heating

I will let you know what I find just got home and don't feel like going out in the shop .long day, but impeller is on motor changed that one will check ports tomorrow and see if I can ream the risers out , could I just acid bath the risers to get the rust out

 

[Taz59]

Re: 1997 volvo penta cobra sx manifold over heating

Sounds like the same engine as mine,1997 Volvo Penta 5.7 TBI .it will have a stand alone pump and a engine circulation pump.you in the water or on muffs.

 

[irawalls]

Re: 1997 volvo penta cobra sx manifold over heating

ok found problem... the 97 models i know for sure have flappers in the exuast to keep water from backing back into the exhaust... well in 98 or 99 volvo found that they were not needed. well mine had them but they were laying in the bottom of the exhaust tube and in the flex hose in the stern drive.. which blocked the exhaust from escaping and caused the bellows to overheat and melt the bellow exuast hoses, I also put new risers on the boat as well but now im thinking that was a waste of money but eliminated that question anyway.. thanks for everyones help, I am sure i will be on here again.

B==bring
O==on
A==another
T==thousand $$$$