Load noise for motor sounds like exhuast

[cajunman930]

I have a 2002 90 four stroke and I hear load exhaust noise where could this be coming from and how can I fix it

[noelm007]

remove the lower cowl/covers and have a look near the hose attachment for a hole near the steel plug with the hex hole in it, then when you see the exhaust burnt through, decide whether to weld, or fix properly and replace the engine holder.

[cajunman930]

Lower cowl

is the lower cowl the 2 split covers on the lower part of the motor or under the main cover

[Moonlighter]

Yes.

Take both side covers off, there are several long bolts attaching ithe covers that undo from the starboard side, and then check on the port side below the water flushing attachment point. Using a hex head socket on an extension is better than trying to undo them with a screwdriver.

This is a known corrosion place on the earlier engines like yours, corrodes thru to the exhaust where a steel plug (like a welsh plug) is fitted into the alloy engine holder. You will also usually have engine running poorly or stalling as well if this is the problem.

In any case, you will see it immediately when you have the covers off if this is the problem.

Let us know ho you go.

[cajunman930]

Thanks again I will keep you informed of the outcome

[redlowrey]

I would have thought if exhaust gas was leaking at the plug, he would have noticed a rough idle, and down on power with the check engine light coming on with a map sensor code. Have a look and see that the little exhaust pipe has not fallen out the back of the engine.

[noelm007]

Yep, that's a possibility too, either is easy to check without cost or a lot of time.

[cajunman930]

It looks like the pipe is still in the back of the motor the engine runs fine

[cajunman930]

Ok so far what I found was a burn through on the lower housing and the hex plug was burnt through as well, now I have exhaust coming out of the engine mount bolt on the port forward side of the motor is the a gasket in there or is something burnt out in there also

[Moonlighter]

Ouch! That doesn't sound good.

If you can post up a few photos it would help us see the extent of the problems and exactly where they are. Will help people suggest options to you.

[noelm007]

Kind of guessed you were going to find that....if it were mine, and I intended to keep the motor, I would do the right thing and replace the engine holder, fix the problem once and for all.

[cajunman930]

Going to run it tomorrow, the motor runs fine just a little loud

[Moonlighter]

If that engine holder is burnt thru and showing further signs of corrosion in the engine holder in others places as you seem to be saying, it won't fix itself and will only get worse and do far more damage. The ostrich solution won't work!

Hot exhaust will likely burn engine wiring harness and other components and then you will be going nowhere.

As Noel said, if you intend to keep the engine, most likely a new engine holder will be required.

If you search this forum (do an advanced search as the normal one doesn't work) for "engine holder corrosion" you will find some great threads and specific information including photos so you can compare yours and see what others who faced the same problem did to resolve it.