1996 Jazz boat loss of power after the engine gets warm

[JohnSimi]

I own a 1996 Jazz 120XR. I have the following problem: after the engine runs for about 2-3 minutes I get a loss of power. Until then all work perfect! I've noticed that the carburators get very cold (sign of running to rich). I've replaced the cylinder head gasket since I've noticed exhaust in the cooling system. This didn't fix the problem. Carburators are clean, I checked all valves from the fuel recirculating system and they seem to work , checked the auto enricher. There is no visble loss of gasoline. everything is clean and dry. The engine starts well, idle is good, runs good in low rpm. I suspect ice in the carburators when running at high rpm. Any sugestion on what causes this?
Thank you

 

[Faztbullet]

Re: 1996 Jazz boat loss of power after the engine gets warm

I've noticed that the carburators get very cold (sign of running to rich).

This is not a as sign of richness if fact its perfectly normal due to physics!!! The carbs have a venturi(throat) which speeds up the air flow. As air passing through a restriction speeds up the airflow creates a cooling effect chilling the carb to touch and in high heat /humid condition cause them to sweat externally (condenses the moisture in the air). Your power loss sounds more electrical than fuel, like a rectifier bad causing stator to overheat,failing CDM module or defective rev limiter...

 

[JohnSimi]

Re: 1996 Jazz boat loss of power after the engine gets warm

This is not a as sign of richness if fact its perfectly normal due to physics!!! The carbs have a venturi(throat) which speeds up the air flow. As air passing through a restriction speeds up the airflow creates a cooling effect chilling the carb to touch and in high heat /humid condition cause them to sweat externally (condenses the moisture in the air). Your power loss sounds more electrical than fuel, like a rectifier bad causing stator to overheat,failing CDM module or defective rev limiter...

I will check all electrical components you've mentioned. Thank you

 

[emoney]

Re: 1996 Jazz boat loss of power after the engine gets warm

Are you 100% sure it didn't overheat? There's tons of info here about "Red Stator/etc.etc." and you can also go to cdielectronics.com for a troubleshooting pdf if it is in fact electrical in nature. Lots of SportJet threads over in the PWC/Jetski forum, btw.

 

[JohnSimi]

Re: 1996 Jazz boat loss of power after the engine gets warm

Are you 100% sure it didn't overheat? There's tons of info here about "Red Stator/etc.etc." and you can also go to cdielectronics.com for a troubleshooting pdf if it is in fact electrical in nature. Lots of SportJet threads over in the PWC/Jetski forum, btw.

No overheating. I tested the warning sensor and it works fine . I have the service manual and I will check all electrical components. The only thing is that I have to do it in the water after the engine gets warm. I will post the findings as soon as I do the tests.

 

[79Merc80]

Re: 1996 Jazz boat loss of power after the engine gets warm

You should try the Force/Chrysler forum as that's what your engine really is.

 

[4shore]

Re: 1996 Jazz boat loss of power after the engine gets warm

Check for blockage in fuel line. Trace from under screen on fuel pump to pick up tube screen in gas tank. my jazz did the same thing.

 

[JohnSimi]

Re: 1996 Jazz boat loss of power after the engine gets warm

Need help with the exhaust manifold! After checking all the electric parts, fuel lines, filter, oil pump, the problem is still there. I've decided to remove the exhaust manifold to replace the gasket. Needless to say that 5 of the 25 bolts broke from the head. I used vibration, penetrating oil, applied pressure, NOTHING worked!
Any suggestion on how to remove the manifold?

 

[JohnSimi]

1996 Mercury 120XR Sport Jet exhaust manifold removal on a JAZZ Bayliner

1996 Mercury 120XR Sport Jet exhaust manifold removal on a JAZZ Bayliner

Need help with advice on removing the exhaust manifold on this engine!
It has 25 bolts and 5 of them broke at the head. I used vibration, penetrating oil, applied pressure...nothing worked!
How is this operation done at the shop? A rebuild engine has to have the manifold removed. I've never had problems with broken bolts until now. Thanks

 

[4shore]

Re: 1996 Mercury 120XR Sport Jet exhaust manifold removal on a JAZZ Bayliner

Re: 1996 Mercury 120XR Sport Jet exhaust manifold removal on a JAZZ Bayliner

Need help with advice on removing the exhaust manifold on this engine!
It has 25 bolts and 5 of them broke at the head. I used vibration, penetrating oil, applied pressure...nothing worked!
How is this operation done at the shop? A rebuild engine has to have the manifold removed. I've never had problems with broken bolts until now. Thanks

If the seal from the manifold is moving from the block or broke loose' Make sure to take off or remove the lower rubber exhaust tube from the bottom part of the manifold. If all is cleared it will come off. No tricks. Bolts can swell from rust though you may need a rubber mallet.

 

[JohnSimi]

Re: 1996 Mercury 120XR Sport Jet exhaust manifold removal on a JAZZ Bayliner

Re: 1996 Mercury 120XR Sport Jet exhaust manifold removal on a JAZZ Bayliner

I wish it was that easy! The rubber connection is loose, so is the hose. Still the manifold is not braking loose from the engine block!