LambRB

I know the Opitmax 225 is a 3.0 liter. Are you sure a ProMax 225 is a 2.5? I'll check and get back with you.

apache21

If you want twins sell your 21 and buy a 24. Go with the single 300. Also a 2.5 200 with a 260 portmap would also be nice.

sd11856g

Iam still thinking a 300x would be perfect they just are hard to find used for a good price. The twinns on a 21' would be something exotic though! I will keep searching to see what I can find

Swede

I had a 21' Skater copy(Lightning) with a pair of 280's and loved it. I wish I still had it. The boat was built with extra knees at the centerline of each engine. They put on about and 24" long tunnel extension plate which helped with the extra weight of the twins. It ran right around 120 but I still had like 15psi of water pressure but couldn't get the engines up anymore without a lot of work.

Todd - 133mph. That cooler than the 142 in the Spectre.

Propster

Glad you brought this up.

LambRB, I would give anything for a ride in your 21 with twins.

I talked to a guy on the east coast that built a nice 21 Skater with twin drags (Mercman).
http://forums.screamandfly.com/forum...ghlight=Skater

He didn't set it up quite the same as you did. He ran jackplates and short shafts. He said he had to keep it under 30 or over 90, there was a terrible ride and wicked porpoise between 30 and 90. For that reason, it made it tough to use as a family boat. My Skater with the single 300 only has a wicked porpoise between 50 and 70. He thinks the tunnel didn't have enough lift to carry the twins until you got going over 90. He ended up riding mostly on the flat surface between the tunnels until it was able to develop lift. Basically made it a flat bottom boat with a wicked porpoise.

I still would love to put twins on mine, I just want to make sure it could work before spending all the time and money to do it.

ospreyproduction

He sold it after it scared the poop out of em!

WARLOCKDAVE

I also had a 21 with twin 2.5's. The boat was originaly set up for a single but someone converted it for twins. Like Mercman, it had a unreal porpouse between 75 and 80. When I say unreal, I mean Scary unreal! If you could drive through it, which I did on several occasions, the boat FLEW. Go find a 21 originally set up for twins or get ready for a real wicked ride. I am told that the 21 was originally designed with the omc V-8 in mind. There were less than 10 21's with twins rigged from the factory. Later, Dave

WARLOCKDAVE

By the way, I've ridden in Todds 21 before he sold it and that boat was a WEAPON!!! Later, Dave

sd11856g

I wonder what skater did with the twinns they built to keep them from the porpoise problem, there has to be a way to do it right.

fastskater21

Mine is a original 21 rigged from the factory with twins. It will porpoise from about 65 to 80. Not that bad just hammer the gas turn a little right then left and next thing you know you are well over 100. Do those people who convert singles to twins only run off the single gas tank.