boat lacking power

Ok guys, I have a problem. I have a 2000 Tige 20i with a Merc 5.7 350. It's fuel injected. The boat is not wanting to plane out when under load, and the engine alarm is going off. It's running smooth, and engine temp is normal, as is oil pressure. Any thoughts?

run a compression test. you can buy a tester at autozone for 25 bucks.

what is a compression test going to tell me?

Compression test will tell you if you have a bad cylinder in your engine. Bad meaning something in the clyinder/piston setup (rings) are not holding compression thus not allowing for the fuel and air to combust. No combustion equals no power.

m-

Wouldn't poor compression prevent it from running smoothly or cause it to miss?

have you changed your oil recently? i realize the pressure is good but i would at least check the oil level. i would check all the spark plugs, wires and distributor cap.

if compression loss was easily detected they wouldnt make a tester for it. look for less than a 10% difference in each cylinder. your compression should be around 150-170. bring the engine up to operating temp. plug in the tester and turn over the engine about 4 compression strokes.

Could be the water pressor sensor. It screws into the transmission cooler. If it goes bad the guardian alarm will beep and go into some sort of protect mode and run at 90% power. Or could be some sort of blockage from the inlet side of the cooler. I'm having the same type of issue with my Mercruiser. The power loss isn't really noticeable until under a heavy load. Otherwise it seems to run just fine. I haven't taken it in yet, but I'm thinking this is the problem. I was told the computer code is something like "blk press psi".

Interesting. Do you know what said sensor looks like? Any way to bipass it?

I haven't got a link to an actual picture, but in this diagram it is #17. It screws right into the transmission cooler. I don't know of a way to bypass it. I changed my cooler out and that is when mine started beeping. I don't know if I somehow damaged it taking it off the old and putting on the new cooler or if it has to be re-set somehow when changing. I'm going to talk to my dealer and get his thoughts.

Does your boat seem to run fine if not under a heavy load?

http://www.perfprotech.com/store/ass...,7585-300.aspx

Is it throwing a code? When was he last time this boat had a tune up? Does it sound like it is hitting on all cylinders? Sounds to me like you might have old plugs and erroded gaps that are not giving you good ignition under load.

Good luck with it.

I don't have a scanner, so I dont' know if it's throwing a code. I keep it on a lift and am over an hour from a dealer, so if it is a somewhat easy repair, I'll try to do it myself. I'm planning on picking up plugs and wires tonight, but it is running smoothly. The strange thing is this happened a couple weeks ago. At the same time, I discovered a bad battery connection, so I corrected that, and the problem was solved, so I thought. Put about 10 hours on it, and then bam, lack of power and alarm sounding.

Email me your contact information to Tony@tige.com and I'll have our service department contact you.

Tony@Tige

I had the same prob on my 99 21i and it was a power issue. Perhaps your battery went bad because of the previous issue? Mine was corrected by cleaning all battery cable connections and scuffing them real good. If you have a double bat setup you could switch your batteries to test this if you know the other one is good. Might save you some coin......