Hole Shot Power

[csl]

Curious if My 351 is needing an overhaul. Motor is running smooth and purring finally. Carb is freshly rebuilt and seems to be operating great. My only problem at the moment is that it doesn't have much hole shot power. If there are a few people in the boat, it takes too long to pull a rider up. Once on plane, it seems ok but still not like it should. Compression all around is 105-110 and motor has 840 hrs. Is this about the time for a rebuild or is there something I need to tink with more? I know props can make a difference, but it feels more like a power issue than prop. It also has a very slight amount of white smoke coming out of exhaust while cruising. Thinking it may just be getting tired in its old age.

[Jetlink]

How's your prop look? Any bad dings or nicks in it?

[villain]

Time for a rebuild. Compression should be 150ish.

[csl]

prop is great. The PO hit a stump in 07 and replaced everything from the tranny down. So its all brand new looking

[dirtydawg]

Time for a rebuild. Compression should be 150ish.

also timing chain/gears get worn and timing suffers causing power loss. I,d rebuild.

[Salty87]

rpms at wot?

take a look at your prop and see what you've got. rule that out before rebuilding. 840 hrs is nothing although the compression is a little low.

[csl]

as far as my rpms, i will have to check that for sure next time im out. can't give you an accurate answer on that now.

My prop is a four blade, 13/13. let me know what you think on that. Its in perfect shape. Thanks

[Supra_Comp]

I would suggest a rebuild. I just went through the same issue with my 85 Comp, could barely pull up a skier with 2 people in the boat.

I had 3 cylinders @ 108 and the other 5 @ 115. A tired motor will always run smooth at idle since it has hardly any compression to work against, but can be a PITA to get started sometimes.

Also, with a vacuum secondary carb setup the motor isn't creating enough vacuum to open up the other two plates so you are essentially running on half the cfm of air going into a tired motor....bad combo.

[wotan2525]

I think a rebuild should be the last thing you do after exhausting all other options....

What kind of RPMs are you pushing? When was the last time you did a tune-up? (Wires/plugs/points/rotor/cap/etc)

[csl]

I think a rebuild should be the last thing you do after exhausting all other options....

What kind of RPMs are you pushing? When was the last time you did a tune-up? (Wires/plugs/points/rotor/cap/etc)

I plan to be on the water tuesday night. I will watch the rpm's then. as far as a tune up, beginning of last year that was all done. I changed my plugs first of this year again because a couple had an external spark going on. Everything is running smooth, no real issue that I can find. Just lacking the power it should have.