140 hp johnson maximum rpm range

[EDDIE1962]

Does anyone know what the maximum rpm range on a 1987 140 v4 johnson is? Thanks in advance.

 

[Dhadley]

Re: 140 hp johnson maximum rpm range

You'll get the most life out of it if it's set up between 5800 and 6000 with a normal load on most recreational boats. Some packs have limiters, you might take a look at yours and see. It'll be printed on the pack - like 62L or 67L or similar.

If you're asking what's the most rpm a stock 87 140 will turn, you can get them to 8000 but you have to play with the ignition & reeds.

 

[EDDIE1962]

Re: 140 hp johnson maximum rpm range

Thanks .

 

[splitshot]

Re: 140 hp johnson maximum rpm range

how long would a motor live if you turned it that high...i would have thought it would fly apart before 8000 rpm

 

[Dhadley]

Re: 140 hp johnson maximum rpm range

Modified motors will turn considerably higher than that. When we raced the V4 about the only time we had to rebuild it was when I got some "brain-storm" that didn't work. Or the weather caught us. (Again my fault for not rejetting or otherwise compensating) We turned a very modified V6 higher than that for 2 or 3 years without incident.

 

[EDDIE1962]

Re: 140 hp johnson maximum rpm range

17 FT. Stratos bass boat. I am using a 22 three blade stainless right now. What would you use to get top speed without killing the take off.

 

[dmercurio1]

Re: 140 hp johnson maximum rpm range

I have the same 140hp johnson as you and the previous owner told me to try and keep it a or under 5000, i just figures he didn't know what he was talking about.