[Kitto]

Okay, here is the skinny. I have a 200 Diablo with a 5.0 V8 with a Alpha 1 drive. I live in Northern WY and do most of my boating on a lake that is at or near 5,000 ft. elevation. Just today we were out boating and with just my two small kids and wife at the helm, the boat was unable to get me out of the water on one ski. Just a few days ago with two more adults and two small kids in the boat I was able to get out after sucking in most of the lake water in my nose.

I have three props 18 pitch SS, 18 pitch 4 blade, and a 15 pitch, blade as well. I really don't see too much difference in RPM when I hit it, most of the time it barely gets to 4000 rpms. When cruising with the 18p SS blade, at WOT I'm around 4500 and it runs great around 40mph (gauge). the 15p gives me a little more rpm, but was uable to provide enough punch to get me out of the water.

Is this an engine issue (it runs great, no sputtering, cutouts, etc)? Is elevation just sapping my power? Is the engine tired?? Please help me out. I used to get out of the water behind an old Seaswirl with a 4.3 no problem. Any advise would be greatly appeciated. Thanks. ( Sorry this is soo long)

Craig

[WetWilly]

Hi Craig, the best way to check if the elevation is causing problems is to "read" the spark-plug. Remove a spark-plug or two and see if the insulator near the tip (spark side of the plug) is tannish in color, if it is, your fuel mix is OK, but if the end blackish or covered with soot, you're too rich and you need to re-jet leaner.

I recommend start here before changing anything else, if the motor isn't running at it's peak, everything else will only make the situation worse.

WetWilly

[indykoch]

With a 15 pitch, you should easily be able to hit your RPM limiter. I think there's more going on here. Some may be sick of hearing me say this, but it's from my own experience - do you have any knocking or engine "growl"? Your gimbal bearing could be bad and robbing you of power.

[Kitto]

Indykoch,
The interesting thing about all of this is there hasn't been any unusual sounds coming from the motor. It sounds pretty tight. It is pretty hard starting the first time I start it, however, throughout the day it then cranks right up. I haven't had a chance to check the plugs, hoping to do that tonight or tomorrow night. Thanks for the help, much appreciated.

[GrayDog]

Check your props to make sure they haven't spun the rubber bushings. I had the same problem until the bushing finally gave way completely and I could only idle my way back to the dock.

[Kitto]

I was concerned about this. How do I check them, what would they look like if they are worn out or what would the look like if they are okay? Thanks for the advice. Craig

[GrayDog]

If they haven't completely spun out it is really hard to see. I sent mine out to a propeller repair shop here in Florida as the cost of rebushing it was only around $70 and took 2 days.

Here's a link to Michigan Wheels repair locations.

Good luck

[IowaWing]

A spun drive bushing will raise RPMs with little change in MPH so it is probably not the bushing.

Are the props in good condition? No dings or missing chunks are there? Bent or unbalanced props create turbulance that could be slowing you down.

The anchor isn't dragging is it? How about weight load... try lightening the load by taking out the extra coolers and stowed anvils and see if it performs better.

Have you thought about going on a diet?

You could always install Smart Tabs 'cuz they seem to help to get on plane faster. (And Mikeyt likes them)

[Kitto]

Har, Har Yes, I'm considering the diet piece, but not until summer is over! I have checked and re-checked bowlines to make sure I'm not dragging an anchor... or the trailer for that matter.

Spoke to a Mercury tech this a.m. and he thinks it has something to do with the moter. They have a dyno machine and will hook it up and see if there is issues there. Could be a bit pricey though. I'll keep you posted and in the meantime stick to salads and Lite beer.

Craig

[greencanuck]

Just throwing this out here but you mentioned a hard start. If it has a distibutor and is not fuel injected the timing being too advanced will cause this. The plug tries to fire on the up stroke and jam the piston back down too early. It almost cranks like a weak battery. You will get great gas mileage but poor HP.

A lake at 5000ft I am still trying to get my head around that one. There must be one hell of a water fall somewhere. Good Luck with the motor gremlins.