Johnson 115/90 crossflow powerhead questions

[MotorheadI000I]

What years would match up to a 94 fling motor, omc/johnson 115 crossflow from what I have gathered. What years would match up for the power head? The Bottom needs to bolt up the same and that. My power head cracked the short block. So I need to find a new one and found a early 80s and wanted to know if it would work. I know the 90 horse would work any other motors the same?

 

[Dhadley]

Re: Johnson 115/90 crossflow powerhead questions

Welcome!!

I'll assume we're talking about a Turbojet. Any V4 crossflow from 1979 on will bolt up. However, you need to look at the shift linkage on the one you have. If it uses the type linkage that uses a threaded hole behind the starboard lower pan mount you'll have to be sure the new powerhead or block has that threaded boss or has the casting to make it.

 

[MotorheadI000I]

Re: Johnson 115/90 crossflow powerhead questions

yea its a turbo jet, the stupid thermostat got stuck opena nd poof it went. WIll any crossflow bolt up including the V6?

 

[Dhadley]

Re: Johnson 115/90 crossflow powerhead questions

Any crossflow V4 from 79 on. But you need to know if yours needs that boss. Early model V4 cf's motors don't even have the material there to drill & tap.

 

[ezeke]

Re: Johnson 115/90 crossflow powerhead questions

I used the block from a 1979 140 last year for my nephew's 1994 Four Winns boat - same as yours. You have to swap the bypass plates and all ignition components. I also used his cylinder heads. Hope that helps.

BTW, it does not have the shift cable at the engine, but outside at the jet drive.

 

[MotorheadI000I]

Re: Johnson 115/90 crossflow powerhead questions

Ok but the 140 is a V4 still I thought that produces, if Im not mistaken, a little less power actually, unles you put the high compression 115 heads on it. YEa I have been reading up alot on the motors lately. I was wondering though if I could stick a 175 or something v6 cross flow in there as well, if lets say I found one =p

 

[ezeke]

Re: Johnson 115/90 crossflow powerhead questions

For a V6 crossflow you would probably have to modify the cover for the engine compartment. The boat is already heavy at the stern, so maybe moving the oil tank and battery forward would help a little.

The drive modification kits in the later models help.

As I said before, I used his cylinder heads - the orignal ones that came with the boat.

 

[MotorheadI000I]

Re: Johnson 115/90 crossflow powerhead questions

O yea I understand the reason why you used the heads. The 140 heads were a lower preformance head anyways, at the prop the 115 makes more horses =D From that I read. So yea, still looking for a motor, 90-115, Even a 100 horse would work for now. Any one know were I can something that will tell me if its a cross flow off the serial number by chance? Or is there an easy way to tell. Somone told me to look at the exuast plate in back and if its a bubble back then it is, but I have a couple that people are claiming are cross flows that dont have that...

 

[seamoors]

Re: Johnson 115/90 crossflow powerhead questions

hello,
I was told by Dhadley the following:
Yes. A looper does not have any bolt on covers. The crossflows have exhaust plates / covers, intake by-pass covers and water jacket covers all bolted on. (Lots of bolts) The loopers have no covers over the exhaust or intake areas nor a water jacket cover on the heads.

Not to mention the 90* looper is flat out a bigger powerhead.

 

[ezeke]

Re: Johnson 115/90 crossflow powerhead questions

Seamoors is correct, and of course there is the fact that Four Winns never used anything but the crossflow engines in their Fling models. The looper would have required a different cooling system and adapter.

The generalizations about the 140 are not universal. The OMC 140 becomes a looper in 1985, before that it was a crossflow and completely different engine. What was the crossflow 140 in 1984 basically becomes the 115 crossflow in more recent models, including yours.

The big bore 90 degree looper 140 will outclass the 140 crossflow and the 115 crossflows hands down in every way.