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View Full Version : Exhaust leak on a 25 ZX?



Mckillop
05-05-2011, 06:42 PM
Yesterday I was taking a look at my engine as it was warming up and noticed a very small amount of smoke or exhaust coming from under the port side exhaust manifold? I recently had the compression tested and serviced and new plugs installed, so the boat is running pretty well. The engine is a stock 502mpi with corsa silent choice exhast and low hours on the motor. I am wondering if there may be a small crack in the manifold? If there is a crack and I need to replace the manifolds, what would you recommend for a replacement? Since it is a stock motor, should I just replace with stock manifolds? Or would it be worth it to get some nicer headers or some EMI manifolds? At this time, I don't really plan nor do I have the cash to throw a ton of money into the motor. But if I can get some extra noticable power out of nice manifolds I would consider. Anyways, I would appreciate your thoughts on this. Like I said, it was a very small amount of smoke. Hardly noticable unless your face is right on top of the manifold.

mrfixxall
05-05-2011, 07:26 PM
Yesterday I was taking a look at my engine as it was warming up and noticed a very small amount of smoke or exhaust coming from under the port side exhaust manifold? I recently had the compression tested and serviced and new plugs installed, so the boat is running pretty well. The engine is a stock 502mpi with corsa exhast and low hours on the motor. I am wondering if there may be a small crack in the manifold? If there is a crack and I need to replace the manifolds, what would you recommend for a replacement? Since it is a stock motor, should I just replace with stock manifolds? Or would it be worth it to get some nicer headers or some EMI manifolds? At this time, I don't really plan nor do I have the cash to throw a ton of money into the motor. But if I can get some extra noticable power out of nice manifolds I would consider. Anyways, I would appreciate your thoughts on this. Like I said, it was a very small amount of smoke. Hardly noticable unless your face is right on top of the manifold.


seems you just had the tune up done i would suspect a loose sparkplug..it will run fine until the plu blows out..i would grab ahold of the plug boot and see if the plug wiggles..or run a spark plug socket over them and snug them up..

Mckillop
05-05-2011, 07:27 PM
Thanks, Ill check that first.

mrfixxall
05-05-2011, 08:21 PM
Thanks, Ill check that first.


If the exhaust manifold was cracked their would be water coming out of it to..if the sparkplugs are tight then you may have a manifold gasket going out but it would usually make a popping noise which would be a exhaust leak between the cylinder head and the exhaust manifold..

MOP
05-05-2011, 09:22 PM
With a stock engine don't waste your $$$ on headers, you need some fairly serious mods to gain anything. Many of our group have been disappointed!

The Hedgehog
05-05-2011, 10:50 PM
Good exhaust is a nice mod. Like Phil said, you won't notice much other than some bling and a little more throttle response. If you plan to build the engine up, it is a must and a great first step though.

Try Fixx's stuff first.

Mckillop
05-06-2011, 11:19 AM
Thanks for the responces. I got into the engine compartment and gave a good look.(It sure is nice having that much room compared to my 18C) Thankfully I don't have any fluid or rust stains comeing out from around the manifold or risers, so at least I don't have to worry about that. I'm thinking it might have been a little oil on the engine that was burning off. Like I mentioned, it was just serviced so there is still some resedue on the block.

As far as upgrading the manifolds and risers, thanks for the advice. I may keep my eyes out for a nice used set, but it doesn't sound like it would be worth spending $2K-$3K at this point.