Hole Shot????

[jpross]

I have a late model 70's ,18 foot Hydrosport (graphite) bass boat with a 77 Johnson 115, that will not plane. The prop that was on the motor when I purchased it was a 23 pitch, steel.

Purchased a 19 pitch, steel, yesterday and off to the lake for the test run. Guess what....same problem! After messing with the trim and having my buddy move to the front of the boat it finally popped up and took off.

Should I be looking for an even lower prop/pitch?? or could this be engine related??...Please help.

 

[steelespike]

Re: Hole Shot????

You may be missing a cylinder,or perhaps throttle isn't opening all the way.
Check the compression.Normally you would trim in for hole shot.(prop closer to boat) A 23 may be a bit too much unless the boat is ultra light.but 19 should plane.What rpm and speed did it run at full speed?

 

[nlain]

Re: Hole Shot????

I would go through the tune up, check the carb, run a compression check, be sure the engine is making full power, check on the weight of the boat per mfg specs, then weigh the boat, make sure it is not water logged, it the information is available from the mfg, check the specs on engine, boat, prop combination from them. Search this forum, there are multiple threads of a similar nature, there are instructions on how to adjust the engine height to get the antivent plate even with the bottom of the boat or maybe just above. I am not an outboard person but the engine basic I mention above are the same, make sure the engine is working properly the move to the next step. You at least have a place to start now, others with more knowledge in this area will be along shortly to give more advice.

 

[Randybeall]

Re: Hole Shot????

Steelspike pretty much covered it, check to make sure the engine is running correctly. How long have you had the boat? If long time, has it run better in the past? Give it a full throttle run on smooth water and record top rpm of the engine, speed, preferably from a gps, and what prop and load you had on at the time. That information will allow people at a distance to figure what you need to know. Even more additonal information can be gained from where your prop and anti-ventilation plate is in reference to the bottom of the transom. Pics as well if possible. The more information you supply the better the analysis. Happy boating.

 

[jpross]

Re: Hole Shot????

Thank you all for the quick responses! I've only had the motor for two weeks. Before I bought the motor I had the seller run a compression test. Three are at 125 and one at 120. From what I've heard that's pretty good for the year of the motor.

As far as the rpms, I failed to mention that the tach is not currently working. Plan on getting this fixed this week,

I will try to get some pics as well.

Thanks again steelespike, nlain, & Randybeall.