2002 mercury 300x wont go on plane

[stoker2001]

thanks for everybodys response and suggestions but i found what was wrong
...lol cant believe it but hey, it is what it is.

so i took off the throttle body to have a better look at the reed valves with a camera...looked at the bottom and there it was...the stupid rubber sealing ring that goes on the throttle body had fallen at the bottom of the plenum matching perfectly the bottom so when i first looked in the plenum earlier i never saw it....lol i just laughed! but at the same time i was thinking this couldnt just be it... so back to the ramp and back it in. let it warm up and tried to take off.. success! couldnt believe it! there a soight hesitation of maybe a second before spooling up but its a trough hub prop. seems to runs great now...mannn...
ill still get the injector flowed and ill do reeds also. luckly no further damage was done form that thong being down there!

SO,the stringy oring was caught between petals and cages keeping reeds from sealing on just the bottom cage?

[RSWORDS]

i read about those. i dont quite understand what they do though..

Same as milling the front. Easy to Install.

[mistah_max]

SO,the stringy oring was caught between petals and cages keeping reeds from sealing on just the bottom cage?

this ring that seals the throttle body on the cowl.

[JPEROG]

You can buy an aluminum billet top ring from Mad EFI so that doesn't happen again. Its amazing how much a thru hub loads the motor down low. The direct inject (XS) motors make more torque down low and are not so fickle on propeller choice.

Glad you got it solved -

Joe

[Chaz]

i read about those. i dont quite understand what they do though..

By sinking the reed block into the crankcase, you decrease the crankcase area by the volume the dressed reed block displaces. I would estimate between 15~20cc .

While at the same time increasing the plenum volume 4.5cc ..





Rubber coating was a quick and easy way to finish the blocks without machining and polishing a metal surface ...
Unfortunately , it tends to look like the desert floor after a while ..

And seals like ....

[mistah_max]

You can buy an aluminum billet top ring from Mad EFI so that doesn't happen again. Its amazing how much a thru hub loads the motor down low. The direct inject (XS) motors make more torque down low and are not so fickle on propeller choice.

Glad you got it solved -

Joe

initial test after i found the rubber ring was done alone with a 38 promax. takeoff wasnt perfect but it wasnt bad either.
But, the next day i went for a ride with the gf and i could barely get on plane with the 30 bravo 1 with 4 holes in it. took 4-5 seconds to pull up rpms and start slipping.. cant believe how much of a dog it is compared to a xs. once on plane it ran good. actually i ran my best speed of 93mph with a passenger with more left. but it definitely needs more holes to help on takeoff. and i need to find a 15in overhub prop for next year i think..

[JPEROG]

I typically run 4 blade over hubs on my stuff. The 300R is the solution. I guess we all need to wait until they start to come out on the used market.

Joe