2.4 Cold seize cause this?

[coffeeguy]

Water pressue was 13psi, it has open carbs, cowling has venting on the side and top rear to allow air in and out but not a direct path to the carbs ,stock 2 piece adaptor plate.. I have run the same set up off and on over the years but usually in the summer when corrected air is more in the 2000+ft range(based on alky motor experiences) The air was cold and crisp and I would guess in the 800 ft range. I now see this was an incident that was probably going to happen due to my inexperiece in tuning and had been posboned by dumb luck. The motor was strong. I will replace the piston an start high with the jetting . Thx to all the replies.

[rjdubiel]

It ran lean up top. With open carbs I would run 76/78 mains minimum and you would be good all year I would guess. Maybe if 30 degrees out you would want 78 or 80 and when 100 you could go to .074 in 1,3,4,6 and .076 in 2,5. Most run cylinder 2 and 5 one jet size bigger as they are the hot cylinders most agree.

and I am by far a novice, no professional here!

[Dave Strong]

Water pressue was 13psi, it has open carbs, cowling has venting on the side and top rear to allow air in and out but not a direct path to the carbs ,stock 2 piece adaptor plate.. I have run the same set up off and on over the years but usually in the summer when corrected air is more in the 2000+ft range(based on alky motor experiences) The air was cold and crisp and I would guess in the 800 ft range. I now see this was an incident that was probably going to happen due to my inexperiece in tuning and had been posboned by dumb luck. The motor was strong. I will replace the piston an start high with the jetting . Thx to all the replies.

Temperature can really mess with you, fine all year then temp drops 5deg below your usual low temp and your lean.

Dave

[Capt.Insane-o]

Why people take off the airbox on stockish type motors is beyond me. My pretty mellow 2.5 on the vector turns over 7500 just fine with an airbox and is pretty crucial to jetting.

[rjdubiel]

For the bling! For the bling.

[rjdubiel]

Don't do chit but get gas and oil all over my cowl and pan

[Capt.Insane-o]

I like to take my cowl off twice a year. Once to put the motor on the boat and once to take it off the boat.

[nitro_rat]

I've spun 2 liters to 8k with the air box on, I like to run the 2.0 type clam shell cowls so I do ditch the air box on horizontal carb motors. I hate that 2.4 200 plastic latch setup...

[Chaz]

Did your Wiseco's have an anodized crown and underside .. ???

If so, they don't show color or fuel wash like a bare aluminum crown does.

Just something for the forensic pathologist's to think about ...

[racer]

Jetting, ignition and wall clearance aside what I dont like is the ring on piston top thats about the size of the squish band making me think you might have had the block decked or too thin of head gasket and thus too little squish clearance.