Prop help for '86 24' Thundercraft Magnum Express

[Stern5]

Can someone tell me what replacement prop I need for a 1986 24' Thundercraft Magnum Express with 5.7L Mercruiser and Alpha outdrive? I figure the original prop that came with the boat should be optimum but I don't know what the pinch and diameter are. Your advice is appreciated.

 

[steelespike]

Re: Prop help for '86 24' Thundercraft Magnum Express

Welcome,If you read "read this first"and get us as much info as possible;
we can help you find a prop based on the present prop and wot performance.
Otherwise we would have to do the same as you research on the net unless someone has the exact boat,not likely.Also prop selection varies based on your typical load, actrivities
and performance preferences.

 

[Stern5]

Re: Prop help for '86 24' Thundercraft Magnum Express

Thanks "steelespike." I'm new to boating so please excuse my ignorance. The normal I would said three adults and I don't know what WOT stands for but I think it has something to do with the recommended RPM range for optimum cruising speed. I've a four blade prop that is bent - I beleive it's a 16 pinch (J15X16P). I'm thinking of replacing it with another prop that gives you good fuel economy.

 

[steelespike]

Re: Prop help for '86 24' Thundercraft Magnum Express

No problem wot= "wide open throttle"We need your wot rpm and speed.
It should be cost efective to have the prop repaired if you don't have reliable wot specs.
As far as economy Usually a 4 blade works well except for wot speed which might be less than a 3 blade.The 4 bld should have good hole shot.stay on plane better at reduced throttle,
handle better at the dock.
At 260 hp your boat will use about 26 gallons per hour (gph)@ wot.Of course less at reduced throttle. It ,may be possible to improve your fuel use but you would probably need a flow meter to tell the difference.

 

[Stern5]

Re: Prop help for '86 24' Thundercraft Magnum Express

Will have to wait until next spring to have the prop fixed and then water tested to see what the RPM and speed is at WOT. Sounds like 4-blade prop is a better way to go. Does anyone knows what the recommended rpm range at WOT for this boat?

 

[Bondo]

Re: Prop help for '86 24' Thundercraft Magnum Express

Will have to wait until next spring to have the prop fixed and then water tested to see what the RPM and speed is at WOT. Sounds like 4-blade prop is a better way to go. Does anyone knows what the recommended rpm range at WOT for this boat?

Ayuh,... 4400/ 4800 rpms...