20hp seems a little much. I thought I'd pick up a better throttle response, maybe a little torque, and a better sound...... but 20hp...... damn:eek::drink:

C'mon now lets not over exagerate here , have had CMIs on the last 6 boats and never had a prob ..... the whole fvcking universe is a ticking time bomb :evilb:

Bolt them puppies on you'll be glad ya did :coolcowboy: if your still skered let me know what ya want for them ..:drink:

The longer runners will help on an NA engine. 20 HP is only going to be about 1mph.

I switched from Gils to CMI's on my 525SC in my pantera and didn't really notice a difference, but exhaust is not nearly as important on an SC'd engine.
I will say that the CMI's look a lot better and its a lot easier to get to spark plugs.

Just make sure you drain them after every run Jay.

?? Even in fresh water?

5 years on my CMI's no issues

Good advice Phil-- thank you. Gordo, 100% of my boating is saltwater so flush every time regardless. If I were you, I'd do it as well. Better safe than sorry.

Even in fresh water, if you have a small crack anywhere, leaving that water sitting in the headers gives it time to dribble down into the head. Go to crank it up and BOOM. Easier to just drain it.

RHR,
There are plenty of guys running CMI's for years w/o problems, does that mean there's no problem with them or that many others haven't grenaded their engine because their CMI's leaked???



OP,
They are a real potential liability. If the gamble is worth it to you, bolt them and roll the dice. Chances are pretty good you wont have a problem... but if you do it's going to be real costly!

At a minimum I'd suggest having them tested every so often.