sonic28

i have 28 sonic w/350/383 - 375 hp when i first start the motors it sounds like the port is not firing feels like a bad plug or dumping to much fuel.when i take off port motor is running 3000 rpm to get up on plane starboard slacks back about 2500 once warm and on plane both motors run great.even after i slow down no problem.it only happens when sitting for an hour or so.help i set the timing at 8 deg
I'm running thunderbolt ignition.help please

blue thunder

Are those qjets bought from me? If so you may need to lower the float level a little bit.

BT

sonic28

hi bt
i did buy those from you last year but i haven't installed them yet.i wanted to get the motor running before i put on the your carbs.should i just put them on and go from there?the carbs i have on are the stock q-jets that came with the 350 270 hp.but why would one motor due that? also should i rebuild them before or are they all set.
thanks paul
if thats not the problem what else could it be?

blue thunder

Sounds like a choke problem Paul. Try holding open the choke plate while the problem is happening. Should clear up. If that doesn't so it I would try one of my carbs on that one engine. You may need to change the secondary metering rods to a leaner (larger) set. Let me know it you need help picking one. What I had in there ran rich, which is what I wanted. Also your displacement is less which may also have an affect. Check out the choke first thought then we can go from there.

Dave

sonic28

thanks dave
i'll try that first.also do you know or any one else what my top speed should be twin 383 375hp on 1993 sonic 28 im running 4700 wot and gps say 52mph i figured i would run at least in mid 60s what's your opinion