2004 Yamaha F150 Corrosion Issues

[Nautical]

What is all the hullabaloo about corrosion ending an F150. Where specifically does this ocurr, Any pictures of where and details of why and wherefore ?? Thx

[boscoe99]

I am not aware of a problematic corrosion issue regarding the F150.

Now the 3.3 liter F200/F225/F250's are another matter altogether different.

The F150 is known for balancers coming apart and destroying the motor.

[Nautical]

Thanks for the info.. I have replaced the balancer but thought I had read that some f150 has the corrosion problems same as the 225?.Just wondering and trying to get some details as to exactly what is happening..

[boscoe99]

I am not saying that an F150 won't corrode. I seem to recall of people reporting about it but it is so seldom that it is not relevant.

People bitch about corrosion. I sometimes wonder how motors last as long as they do when operated in a salt air environment with salt water being pumped through them, with little preventative maintenance. Salt to me acts like an acid.

[strokeracevt]

What would you say are the pitfalls of an early F115 engine?

[boscoe99]

What would you say are the pitfalls of an early F115 engine?

Detonation damage.

Early F115's have a relatively high compression ratio but no knock (detonation) sensor.

It is important to prop this motor correctly and to use clean fresh gasoline. Use of 89/91/93 octane gasoline will provide some additional measure of protection from detonation. No downside to the use of higher octane except to the wallet. The engine does not use much fuel so in the scheme of boating life use of higher octane is very cheap insurance.

Regarding propping, with the boat loaded use a propeller that will allow the motor to turn at or near 6000 when the throttle is wide open. If the boat is used lightly loaded mind the throttle so as to not let the motor go over 6000 RPM.

Having a clear/transluscent plastic gasoline tank that is exposed to sunlight is a no no. Sunlight will damage gasoline and lower its octane rating. Too low on octane and the motor can suffer severe damage.

[Gungadin]

F150 Corrosion

I am considering purchasing a 2005 Pursuit with twin F150's. Both engines have had corrosion welded behind the thermostat area, one hard weld, one the selling dealer did with JB Weld.
I have read little about corrosion in this area on 150's.
Any advice? Walk away or run? Alternatives to walking away? I love the boat but don't want a huge repair/replacement bill down the road.
Oh yeah, the engines are 2005 and have 269 hours on them and are in Mobile. Thanks!
I have attached some pics of both engines. Other than the weld area the engines look clean. Dealer said after seeing the weld on the one engine he scoped the thermostat area and noticed it was thin so ground away the metal and gooped it up with JBWeld.