Lost MPH

[gcboat]

Don't exactely know where to post this so I'll try here. 2006 Pathfinder 2400 with 250 Yammy 4 stroke. Left in the crappy canal water, some junk on the bottom ( not much ) engine will make the RPM's but I've lost about 15 MPH.
Recorded this with two different GPS units and I know the speed is off just by the feel. What could be the problem? Cleaned the bottom - not spotless .
But 15 mph with just that little amount of garbage on the bottom?
Anyhow I'm taking her to the dealer next Tuesday just thought I'd throw this at you guys and see if anyone had some idea or thought on the matter?

 

[oops!]

Re: Lost MPH

gee i really hope you find your lost mph....i really hate that when it just goes missing........


seriously...no laughing matter.....i just couldnt resist.....


15 mph is huge....

1. clean your hull...

2. weigh the boat and compair it to manufacturers specs.

3. get a compression check

 

[gcboat]

Re: Lost MPH

Thanx oops!

Do you think even with the motor still running at factory rpm's there could be a problem with it? Like I mentioned she's going back to the dealer next week, should I bring this up to them or do you think they just might be wise enough to figure it out all by themselves?
On weighing the boat are you thinking there might be some water intrusion? The hull has not been compromised one bit so that just might be a non issue -hopefully. Checked all the bait boxes and fish wells - no water. All is as it was until that canal episode. HOWEVER, I put her there for my uncle to use while he was down for a few days - hmmmmmmmmmm? I can't see him doing anything really stupid to loose that much top end. But he's not the sharpest knife in the drawer - if you know what I'm saying. Oh well, I'll just have the marina do their thing and hopefully it isn't going to turn into a major Charlie Foxtrot.

 

[steelespike]

Re: Lost MPH

Its screwy to have the same rpm but 15 mph less speed.Perhaps a dinged prop. maybe a dinged bottom,maybe both.If just the boat was dragging down the speed it would drag down the rpm.

 

[Nandy]

Re: Lost MPH

Me think you have a prop problem... Definetly tell the dealer you have suddenly lost mph.

 

[fishmen111]

Re: Lost MPH

This is a long shot, but do you know what prop was on the motor before and is it still the same. Uncle hit something...replaced a 23" pitch with a 19"? Got to stop watching CSI Miami. Please let us know what the mechanics say.

 

[QC]

Re: Lost MPH

Yeah, I'm with steelespike and nandy. Sumpin' is screwy . . .

 

[Woodnaut]

Re: Lost MPH

If you've got the same RPMs at the powerhead (with a clean hull) and your speed is down, then this really sounds like a prop issue. Guys, there's no chance a spun hub would produce these symptoms is there?

 

[fishmen111]

Re: Lost MPH

I was wondering that also, but would think he could feel/hear a slipping prop through rpm variations especially when coming on plane with 250 hp.

 

[Bondo]

Re: Lost MPH

But 15 mph with just that little amount of garbage on the bottom?

Ayuh,...... I'd Bet that's the Problem........