Prop and Pitch

[ToddD]

What is the proper prop/pitch for a 1995 American Skier Volante with a Mercruiser 350 Mag?  My boat does not have a lot of pop out of the hole and then has a hesitation between about 3000-3600 rpms.  Max rpms is is about 4600 and 36 mph.  A guy doesn't think it is compression issue because no blue smoke when starting and it does not spit/sputter at the 4600 rpms.  Thanks

[ToddD]

I was able to pull some numbers off my prop.  On the side it says S916 or S91G and on the end it has !3xL3LH5.  Not sure what this means or if it is the correct prop for my 1995 American Skier Volante.

[RonT]

I didn't recognize the part numbers on the stamping but I can tell you the OEM prop was a 13 x13 x1 LH prop, the tournament skiers received the 13 x 12 x 1 LH prop all were 3 blade, Ni-Bral (brass not stainless) props & these were sand cast props before the now popular ACME props came about.  Your numbers are not adding up, a well tuned proper running engine with a 3 blade 13 x13 prop spinning 4600 rpm will produce speeds around 44-45 mph. Hole shot will be sufficient to pull a 200# slalom skier right up. The 13 x 12 prop will pull hard enough for the same skier to request a softer throttle start because that prop will pull that much stronger and will result in around WOT of around 4600 rpm.
Possible issues:
Odd stainless Chinese prop??
Carb issues (no accel. pump response)
Boat overweight
 

[ToddD]

Thank you Ron.  So would you recommend I go to a prop shop and look for a 13 x 13 or 13 x 12? Our kids, slalom, barefoot, trick, 2 ski, strap doubles.  Thanks

[ToddD]

Hi Ron, here are some pics from the prop.

[backfoot100]

Todd,
I'm a bit confused. You have differing information in two different posts about the same issue.
Your other post says you're getting 36MPH @4200 RPM. This one says 36MPH @4600 RPM.
While neither one is right, the difference in the WOT RPM may point to a totally different issue so confirmation of which one is right would be helpful.
You say that it starts and runs good and the state of tune "seems" to be good. What a state of tune tells you by the "seat of your pants" and what it truly is are two different things. What is your base timing set at? Total timing should be someplace around 36 degrees and all in by 2500-3K RPM. Sticky or broken weight springs could prevent proper advancing. When was the last time you actually did a tune up? What type ignition is in here? What do the plugs look like?
As Ron states a carb issue may be the culprit.

I don't think a prop will do you a lot of good until you can truly rule out ignition and carb adjustments. If it hasn't been done in a while I would suggest a good tune up. Plugs, cap, rotor, points (if equipped) and possibly wires. It's a whole lot cheaper than a new prop and it never hurts.

FYI, I have a friend with an 88 Sanger w/350 Mercruiser that is exceptionally fussy about the timing. A degree off in either direction completely changes performance. I've never experienced such a touchy timing beast.

[ToddD]

Sorry about the confusion.  It is 36mph at 4600rpm.  It had a full tune up including new plugs and wires last August when I had it in for new exhaust system.  I wish there was an experienced American Skier mechanic in Minnesota I could being it to.  I'm tired of these high priced shops, and I am not a mechanic.  I wish I had that ability but I just don't.  I just want a good runing boat to be able to bring my kids out on to have fun.

[RonT]

Prop looks like a stainless import, they're not bad but it's not your problem, not sure if I missed it but what are you using for instruments to get your readings? 36mph @ 4600 with that prop does not compute.
Remember I don't get to the site as much as I would like, so when in doubt call me @ 985-542-4336