Tilting makes it run right?

My 03 carbed F90 misses and coughs and bucks on the transom for minutes last 3-5 times when I start it,on muffs, every couple weeks or so when I can't get on the water. It seems to be missing on 1 cyl. If I tilt the motor +/- 22.5 degrees up from level, it starts to idle fine! and I can return it to level and it idles fine. Could this be a carb float issue? I got this motor used and believe the carbs have never been disassembled or cleaned from looking at them. This happens w, or w/o using the primestart.

Re: Tilting makes it run right?

I have a Yam 50 that WON"T start unless it's tilted all the way down, when it hasn't been run for a while. You'd think the kill switch was pulled. We often have to start it in shallow water at the ramp or at the house, so it's a repeated problem until you get used to it.

I'll be interested to hear what the experts say; I'd guess a float, too.

Re: Tilting makes it run right?

Maybe drain each carb onto clean white cloth to check for water or debris in float chamber...if much trash there then maybe clean the carbs....how would carb floats get out of adjustment unless somebody screwed with them? Good Luck!

Re: Tilting makes it run right?

Don't mess around. Clean, rebuild the carbs and reset the floats and Idle jets. The only way to get them to work correctly.

Re: Tilting makes it run right?

I've been leaning towards the carbs. rebuild for a while, but the motor does run good once it warms up. I know it's time to do it and I think something is sticking or debris clogging in one of the 4 carbs. from the tilting fixing it temporarily. I must confess I am aprehensive about the price to have it done or doing it myself. I have a factory serv. manual and it looks like I might goof something up. But I am sure that by the 4th carb. I'd be much faster and better w the practice w the first 3!. Then I would need to get someone to sync. them and adjust? as I don't have the equipment for that. I'm taking it out one more time and then I'm gonna bite the bullet and fix this one way or the other. Thanks for the advice.