rpm vs speed

[Quick3201]

1974 19' V- Hull Bow Rider, 1974 120hp Chrysler w/ 15 pitch x 13.25 prop. Thanks to all who answered my question. i didn't have all needed info for you. Took it to a shop and he calibrated my new tach to finally read correctly and adjusted the carbs. The result---- 34 mph (gps) @ 5000 rpm. About right for this boat.

New question. Idles OK in gear now. Pulls out OK slowly from 1000 rpm to 2000 rpm, cruse OK at that rpm. Full throttle from 2000 to WOT and it has a serious shake/misfire from 25oo to 4000 rpm. 4000 to 5000 OK. back IT DOWN TO 3500, OK AGAIN. just UNDER FULL THROTTLE AND LOAD. New surface gap plugs, wires, fuel, and good carbs. Any sussestions???

 

[steelespike]

Re: rpm vs speed

You need to put this in the Chrysler/Force forum. You'll get faster more precise help. Good luck.

 

[Quick3201]

Re: rpm vs speed

You need to put this in the Chrysler/Force forum. You'll get faster more precise help. Good luck.

Thanks,
WQ

 

[jerryjerry05]

Re: rpm vs speed

Most time the 15p or lower are used on pontoon boats or large boats.
Your boat should have a 17 maybe a 19.
Operating range is 5200-5500 wot.

Do a compression/spark test.
Then the carbs.
Make sure they are clean and the fuel has no water.
Plugs burning OK??
Rebuild the fuel pump.

 

[Quick3201]

Re: rpm vs speed

Thanks, I'll try the compression test, boat sat for a long time. New fuel pump, clean no alcohol fuel, new plugs. I'll look at the plugs while I have them out. I also have a 17p prop, would that be better??

 

[jerryjerry05]

Re: rpm vs speed

Probably would.

 

[Quick3201]

Re: rpm vs speed

Thanks,