Yamaha Pro50 with 70 carbs spitting fuel from throats

[shooter5635]

Hey all,


Finally got my hull in and got to run the motor. Played around with props for 5 hours or so Christmas Day. Went to take the hood off and the entire inside front of the hood is covered in gas/oil. The motor is a ‘87 Pro50. Custom tuner. Cleaned up ports. 70 carbs. The carbs have the original 150 jets in them. From what I’ve been reading, I need to jet down a size, but I don’t think that would cause the spit I’m getting. Current plan is to pull the carbs and make sure the floats are set correctly. Also going to pull the reeds and inspect. Anything else that I’m overlooking?

[Capt.Insane-o]

Put the air box back on it. Reversion is part of what a carb two stroke does and works with how a motor is jetted.

[FMP]

Did it make more power, you did port work with the reeds in it?

[Roflhat]

Are the reed stops on?

[shooter5635]

Reed stops are on. Pulled the reed cages and reeds are in good condition. Stock steel reeds. She's turning 6000-6300rpm WOT depending on load so I don't think they're floating.

[Jamie Nichols]

My old modded Yamaha was spitting out fuel until I installed some CC race reeds. I can't say it added any speed because I was doing too many things at once. I don't know if the old metal reeds were worn or just not closing fast enough?

[flabum1017]

My old modded Yamaha was spitting out fuel until I installed some CC race reeds. I can't say it added any speed because I was doing too many things at once. I don't know if the old metal reeds were worn or just not closing fast enough?

Stock steel reeds don't have the same response as composite reeds (such as chris Carson Reeds), especially with mods.

[shooter5635]

I was planning on swapping the steel reeds out for some CC reeds, so we'll see what happens.

[Merc 2.5]

I built my 1st 2.5 not long ago and recently put a intake spacer on and cant run Airbox nemore, I was worried bout carbs throwing fuel everywhere and runnin lean but I've experienced hardly any fuel in the cowl and went up to 86 jets , but I run Carson reeds also , pretty clean under hood for no air box, I would think reeds or fuel leak sumwerez. His reeds r a gud investment even if u just wanna experiment, does this motor have a bleed system like a merc? R they leaking?