Diffrences in Johnson 150`s

[badss350]

I have a 91 Johnson Tracker GT150 Pro Series....my cousin has a Johnson GT150 thats says VRO with cross racing flags on it...are they basically the same? They are pretty close in year models...His motor on same boat as mine will fly!! He has gotten 80 on gps...im luckily to get 62..and with same set up ( jack plate, prop etc) he has had no internal mods done...Just has a CDI box that is is diff from mine....not sure if thats alot to do with it or not..

 

[jonesg]

Re: Diffrences in Johnson 150`s

compare rpm's, some powerpacks have rpm limiters.

 

[emdsapmgr]

Re: Diffrences in Johnson 150`s

All 150 crossflows use the same factory block. The difference is in the carbs and heads. Look for the "S" in the model designation. A basic 150 is different from a 150S model. The "S" model is more like a 175, with different heads and the larger carbs. If both your models are designated 150S they are comparably the same engine. They did use different heads between years on the S models and that could account for some differences in compression between them. These models should have come from the factory with a 5800 rpm rev limiter. I doubt an unlimited pack on the GT150would make that much difference, since these low port engines run out of breathing capability around 58-5900 anyway. What would make a difference is if your cousin had a 235S with a 150 cowling.

 

[badss350]

Re: Diffrences in Johnson 150`s

TY for the info....I found out that his GT will turn way up past 6000 with a smaller prop on it....he has tached 7000 but of course the speed was down....my CDI box has 5800 lettered on the side...His just makes more power than mine..mine was rebuilt last year and dosent have that many hours on it. I will go out and get the numbers and make sure both have the S in the numbers...I know his is a true 150 GT since he bought the boat new back in the day..Im going to just keep playing with the jack plate and and see if I can get mine up closer to the 70 mark...