87 blackmax200 overheating

[Thecol]

hello all.the last time i had an ovreheating problem.one of you guys told me to change the head gaskets.and that did it.that lasted about a year.then it started again this spring.ive changed the whole pump imp.housing gaskets.pumps water good from telltale and exhaustports.one thing i noticed was that before i changed gaskets there was no water at ports only telltale.when ichanged them i noticed water from ports.so i new you were right immediatly.any ideas ?im thinking gaskets again,but im pumping from allports and telltale great.

 

[KCLOST]

Re: 87 blackmax200 overheating

Which ports are you talking about?<br /><br />The prop exhaust or the upper exhaust ports or both..

 

[Thecol]

Re: 87 blackmax200 overheating

yeahboth

 

[KCLOST]

Re: 87 blackmax200 overheating

Do you see water exiting the upper exhaust ports at idle/no-wake speeds?<br /><br />If you do, you have a poppet valve problem.<br /><br />Remove the poppet vavle assembly and clean. It isn't shutting or opening too soon. It should be shut under 2500-3000 rpms and only open above that to release water pressure and increase "flow" of water through the water passages...<br /><br />Do you have a water pressure guage, if so what is your idle water pressure?<br />Are you overheating at idle or WOT?

 

[Thecol]

Re: 87 blackmax200 overheating

i was just thinking that the last time i had trouble it was the gaskets.they did the job.but its maybe a year later and im back where i was.it doesnt seem to over heat at idle or in the yard.just when throttleing up.when i back it down cools right off.and pumping good the water is not even hothot.

 

[KCLOST]

Re: 87 blackmax200 overheating

That makes sense, becuase if the poppet is stuck open or opens prematurely, most of the water will not even make it up to the hottest part of the engine...<br />And running on the muffs is a different animal...<br /><br />In addition to the poppet, I would replace the t-stats also, checking compression would also be a good idea...

 

[Thecol]

Re: 87 blackmax200 overheating

the tstats are also maybe a year old.but i have a lowe water pickup so i run it in a tank.

 

[KCLOST]

Re: 87 blackmax200 overheating

Are you seeing water exiting the upper exhaust ports at idle???

 

[Thecol]

Re: 87 blackmax200 overheating

some sray

 

[Thecol]

Re: 87 blackmax200 overheating

spray

 

[KCLOST]

Re: 87 blackmax200 overheating

Then you diffinitely need to look at the pressure-relief valve or poppet, that is the only way that water will exit the upper exhaust port.. And you should not see any untill you are above 3000rpms... If water exits the poppet below that you are dumping water into the exhaust and not providing enough to circulate the block for cooling... <br /><br />Take a look at this link<br /><br /> poppet

 

[Thecol]

Re: 87 blackmax200 overheating

everything still seems like it did when it was running good.i guess ill try it thank you.

 

[Thecol]

Re: 87 blackmax200 overheating

I DONT KNOW.I TOOK IT OFF.IT LOOKED NEW.WOULD IT OVERHEAT IF THE ENGINE WAS MISSING?

 

[Thecol]

Re: 87 blackmax200 overheating

DO YOU HAVE TO BUY WHOLE CASEING AND ALL

 

[KCLOST]

Re: 87 blackmax200 overheating

NO, <br /><br />I would replace the diaphram, spring, gaskets, and especially the grommet and carrier... The grommet and carrier are fixed to the hole that goes into the block... Everything else will come out...<br /><br />Install and retest... BTW, don't push the carrier or grommet into the block....

 

[KCLOST]

Re: 87 blackmax200 overheating

You have to make sure that it is seated against the block to prevent water from passing it.

 

[Thecol]

Re: 87 blackmax200 overheating

WHEN I PUT IT BACK IT WENT IN THE HOLE.BUT WHEN I TIGHTENED IT DOWN I THINK IT IS KIND OF OPEN FROM THAT.IS THAT NORMAL?

 

[KCLOST]

Re: 87 blackmax200 overheating

It will push on the diaphram some,,,,<br /><br />Just for reasurrance, I would replace everything except for the plates... <br /><br />Don't forget the grommet and carrier?

 

[KCLOST]

Re: 87 blackmax200 overheating

And make sure that there isn't a blockage in the exit hole that the water goes past the poppet and into the exhaust...<br /><br />High pressure air or water can flush it if you find a potential obstruction....