I found a couple of small pieces of what appeared to be plastic like material which I removed out of one ( starbd. ) side. The other ( port ) was clear. The manifolds themselves seem warm to the touch and not hot which they should be, but the pipes seem to hot. I am thinking maybe this could all end up being a timing issue, do you happen to have the initial timing specs for idle and advance?

Thanks

Too much timing will definitely cause high exhaust gas temps and the condition which you describe . Take some timing out of it and I bet your problem goes away . My HP500 timing is set at 34* total @ 3000 rpm .

Yeah I know this is true, do you happen to know what the exact idle timing should be? it starts fine but has a slight hesitation when I initially turn it over. Someone told me 8 degree's at idle and I have also heard 10.

Thanks

The initial timing is not generally important, especially when you are concerned about excessive heat. Connect a water hose while on the trailer, remove the prop and run up to 3000-3500 RPM while holding the timing light. As others have said, 34 degrees total is a good safe # on pump gas.

Thanks will do, appreciate the help and information. Sure wish I could locate a factory manual for this particular engine, if you know where to locate one let me know please. Thanks again. I only run marine grade fuel and try and run nothing but 89-93, do you think the 93 is to hot by chance?

Your engine was designed to run on 87 octane . You will gain nothing but a lighter wallet by running a higher octane . Set your total timing as has been described and you will be a happy boater .

Thanks I appreciate that info. Most of the time I get the Valvetec 89 which is sold on the water, good fuel and allot cheaper, if you consider fuel cheap these days!! I did the timing this weekend, found that my engine is not advancing at all. When we brought the throttle up to gain advance the mark actually went the opposite way on the harmonic balancer! Instead of advancing to the higher numbers it looked to me as it decreased! I am in the process now of locating a new module, this could have been allot of my problem all along. Let me know what you think? Thanks again.

Went to set timing a while back, found out that it is not advancing, what next for Gods sake. I ordered a new module from my wholesale distributors through Mercury for the 99 HP 500 carb engine, I sure hope after this all these problems will finally be solved. We have sure missed being on he water with all of this crap.

have you pulled the hose off the oil/p/s cooler(s) ? make sure there is not a bunch of old impellor pieces blocking the flow there...seen that many times...

Yes is was clear. I ordered a brand new Impeller kit complete with housing, wearplate, everything. I also have a brand new module from Mercury Racing and I plan to get this all installed in the next day or so. I will post how it turns out.