Logo
FULL SITE MENU

57 Mercruiser problems advise please

S

shaney

New member
"Hi I have a 1997 5.7 mercruis

"Hi I have a 1997 5.7 mercruiser. The problem I am having is a lack of power when in gear & trying to accelarate. History is had some overheating problems so the cooling system was cleaned down all pumps checked and cooling system now fine. Tried a test run but could not get power out of the engine. Suspected head gasket problem but carried out compression test etc and all was fine. Have checked fuel flows, carby, & ditributor and all fine. Engine starts first time always not missing and running fine. Can idle around in gear but when I try to accelerate the engine really labours and starts to heat up. There is no growth on leg or hull and prop OK. Any ideas or has anyone experienced similar problems?"
 
"Ayuh,.........

My Guess is

"Ayuh,.........

My Guess is,.....
When you had the lack of cooling water issue,.....
You Fried the Flappers,+ they have fallen into the exhaust cavity.....
They're Blockng the exhaust flow,.... So your motor can't Breathe......."
 
Thanks very much for your repl

Thanks very much for your replies and advice will check that first thing tommorrow and hopefully be back on the water soon.

Fingers crossed.
 
""You Fried the Flappers,&

""You Fried the Flappers,+ they have fallen into the exhaust cavity..... "

Which flappers, the ones on the back of the boat?
Thanks"
 
"James,
I believe the f

"James,
I believe the flappers Bondo is talking about are located in the exhaust down pipes between the risers and the outdrive. They stop a back flow of water back up into the manifolds. Fry them and they fall down blocking the exhaust outlet creating enough of a blockage to retard the motors ability to make power/dispose of exhaust gas/excessive back pressure."
 
Could this same exact problem

Could this same exact problem happen with an inboard motor- direct drive? Or something similar?
Thanks
 
where are these flappers locat

where are these flappers located on an inboard?
whats the best way to check these flappers?
 
If you have thru-hull exhaust

If you have thru-hull exhaust they should be on the outside of the hull exhaust pipe.
 
Back
Top