upgradeing to bigger engine and need some advice

[emptypockets2000]

i have a 16 foot bowrider with a 120 4 cyl and am thinking of installing a inline 6 cyl 165 (250 ci)and i am wondering if the outdrive gears will have to be changed or will installing a heavier pitch prop be enough
thanx for any advice

 

[Peaceful Pirate]

Re: upgradeing to bigger engine and need some advice

Rather than a 120 to 165 change, why not consider going to a 140? Like the 120, the 140s are easy to maintain, parts are plentiful and in most applications, you can get by using the same mounting structure. Also, the weight to power ratio in a 16 footer is not going to really be in your favor with a 165. My guess is that a solid 140 will more than meet, and probably exceed, your expectations for a re-power. Just my two cents worth.

 

[Bondo]

Re: upgradeing to bigger engine and need some advice

Ayuh,... The 140hp would be a Drop In... The 6cyl. would Require regearing...

 

[emptypockets2000]

Re: upgradeing to bigger engine and need some advice

the only reason i was thinking 165 is i can get 1 from a friend really cheap and a 140 is not readily available in my area

1 more question is there a simple way to test an engine block for cracks the last time i had the boat out i got water in the oil and i pulled the head hoping it was the gasket but it looked ok so i flipped the motor upside down and filled it up and put 50psi of air on the water side and looked for bubbles to locate a crack but no bubbles were evident so im guessing it must have been the head gasket even though it looked ok
where else could the water come from?