Top speed

[JohnO]

Top speed running light is 37.7.

This weekend I had 6 adults, two big teens and two kids a couple coolers and we hit 36.5 with the top up.

I was kind of amazed. I expected to lose more than that.

Maybe I've got room to go to a higher pitch prop (4 blade maybe?) and increase my top speed? Both speeds were on a 15.25 x 15 yamaha prop with the motor at 5500RPM.

Seems that nothing gets me above 5500 yet I can always seem to get there.

[Drago]

JohnO,

It's really strange. No matter what I pull or how much weight is in the boat, I turn 6200rpm at max throttle?! It appears to be something called prop slip under load. Strange. Very strange.

[JohnO]

JohnO,

It's really strange. No matter what I pull or how much weight is in the boat, I turn 6200rpm at max throttle?! It appears to be something called prop slip under load. Strange. Very strange.

I get what you are saying but the motor doesn't rev limit until 6200. So I should be going above 5500 running lite if I'm getting there running heavy. It seems odd to me that the slips would both put me at 5500. KWIM?

[Wags]

About 30 hours now on my boat, just me with about 25 gallons of gas I got 50.3 gps, had 5 adults and 2 small kids and ran 46.5 gps. Running 200 Suzuki, lifting strakes on the toon, has a real nose high run to it.

[dockholiday]

About 30 hours now on my boat, just me with about 25 gallons of gas I got 50.3 gps, had 5 adults and 2 small kids and ran 46.5 gps. Running 200 Suzuki, lifting strakes on the toon, has a real nose high run to it.

look like you got it whipped. what prop are you running?
doc

[Wags]

3x16x20R Suzuki prop, the boat has a 15 1/2 inch built in set back so that helps it some. Its been a lot of fun.

[Hersbird]

I got 26 mph on GPS on a pretty choppy day with just 2 guys in the boat and not much other gear. That was with the new 15 pitch but my tach wasn't working yet. It sounded about right, 5000 rpm but we'll see. I just ordered a backup 13 pitch for heavier loads. A few days later with 5 people and lots more gear, similar chop, I couldn't get it to rev over 4000 rpm and got only 20 mph. The 13 pitch should work better there.
Thats a 22' 87 Chinook w/hardtop and a old 74 Johnson 115 that needs a tune and the carbs rebuilt.
Next comes skinning the uderside and maybe a Pontoon Waterglide as I think it would really help my boat. Then I hope to go back to the 19 pitch and get it into the mid-high 30's with light load.

[dockholiday]

3x16x20R Suzuki prop, the boat has a 15 1/2 inch built in set back so that helps it some. Its been a lot of fun.

Just checked them out. Nice looking boat. Looks like it weighs about the same (few hundred lbs as mine). Guess the next one I will go with the 200....enjoy.....
doc

[Wags]

Thanks Doc, the Suzuki 200 got me into the 6 cyl so that was a must have for me. I wanted to put the 225 on it that is max rating for the boat but the extra $3500 the wife put a stop to that real fast, ... Love the boat, its great to get the family and friends together on it.