Yamaha 220 won't start

[jd fishnboat]

I have a 1985 Yamaha V6 spclk (220) sitting in a 1986 Nitro MX 250.

Compression on all 6 cylinders is: 100, 100, 100, 100, 98, 95

I have spark at all 6 cylinders

Has new gas, new fuel bulb (pumps up firm)
There is fuel in the fuel bowl of each carb (pulled the drain plugs on each one, all look clean with no signs of old gunky fuel)
Carbs were rebuilt 2 years ago and it was ran last season.

Motor cranks fast, but will not fire. Won't even sputter.

I've tried spraying mix fuel into the carbs.... nothing
I've tried pulling two spark plugs, spray with mix fuel, put them back on quick .... nothing

Choke closes all the way, I've even held it shut.... nothing

I've tried starting with the throttle to the floor and everywhere in between... nothing
I've tried starting with the choke on, and the choke off .... nothing
I've tried starting with the fast idle up, and with it down, and with it halfway.... nothing

This boat is brand new to me (had it about a month)... I bought it without seeing it run, just going off the condition of the motor, a receipt of the carb rebuild, and a decent compression test.

But I can't get it to start... Please oh please tell me what I'm doing wrong

 

[jd fishnboat]

Re: Yamaha 220 won't start

Edit: the only thing I can think of is I need new spark plugs. The old ones look rough. I have new ones on order and they should be in the next day or two. But I would think that even with the old ones I'd at least get it to sputter.

 

[99yam40]

Re: Yamaha 220 won't start

how did you check spark on all cylinders?
Spark tester set to what gap?
Are you sure the kill switch is in place?

Compression, strong spark, timing of that spark, and proper fuel/air ratio in the cylinders are needed to fire properly.
You are missing at least 1 of them. The 1st 3 are easy to test, and then you are left with the fuel.
Too much fuel is just as bad as too little to have cylinder to fire properly

 

[jd fishnboat]

Re: Yamaha 220 won't start

I checked the spark just like I would on a car. Pulled spark plug, connected it back into the wire and held it against a bolt on the block while a friend turned it over.

Is there a better way I should be testing spark on an outboard?

The kill switch is in place, but if it was out, wouldn't that kill the spark? I'll trace it out and test it with my ohm meter.

I figure there's a good chance that these spark plugs are too fuel/oil soaked. New ones should be in tomorrow (shoulda just spent the extra $6 and bought them at the store.) I'm going to wait for them to get here before I start tearing my hair out. I have plenty of other little odd projects to work on with the boat.

My next check if the spark plugs don't make a difference is going to be to bypass the computer. From what I've read if there's a problem with the computer, using the bypass plugs will set the timing for idling back in.

Edit: Oh and thank you very much for the reply. It's really nice to have another brain to bounce ideas off of. Especially when that brain knows what it's doing!

 

[jd fishnboat]

Re: Yamaha 220 won't start

Not to asks too many questions all at once.... but here's another thing that has me confused:

Do the carbs on this motor have accelerator pumps? I thought I read somewhere that they didn't. I know when I push down on the hotfoot it opens the throttle valve but there's no squirt of fuel.

If they do have accelerator pumps then I think I just found my problem.


Edit: Okay, did some more reading. They do not. But I think I found out why my plugs are soaked with fuel. In my old pickup truck if it flooded, I could just hold the pedal to the floor and it would suck a ton more air in allowing it to overcome the extra fuel. I did that with this and I think that just floods it more.

Learning on a curve sucks.

 

[99yam40]

Re: Yamaha 220 won't start

adjustable Spark tester is good to have so you can make sure the spark can jump the proper gap and makes it easier to see the spark. Besides the fact that if you do not give it somewhere to arc to it can jump internal and harm some expensive parts of the ignition system.

If it is sparking then the kill switch is not a problem.

How old is the fuel? Did you just add some new to the old stuff

Might want to hook a small tank with fresh fuel to see how that works, may have to drain and flush the old fuel out of pump, lines and fuel bowls to get the fresh into the carbs.

No accelerator pumps as you found out already, opening throttle will allow more air in just like the old truck.
Bad fuel pumps can dump fuel into crankcase, but only on the cylinders that the pulse ports are on. Stuck needles/floats can dump fuel also.

You can clean carbs one day and if you get some trash or water into them from tank, lines, or fuel pumps you will have to clean them over and over until you clean everything. Do you have a fuel/water seperator filter mounted in the boat?

 

[jd fishnboat]

Re: Yamaha 220 won't start

Got it started!!!

Two problems:

First: Once I got the new spark plugs it I got it to start. But it started over heating....

Second: So I pulled the lower unit (bought off of ebay as a good used lower unit with a new water pump and oil... but they stuffed the wrong impeller in it .. so next task is to change the oil). I put a new water pump on it and it cranks a lot faster than it was... which also helps with starting.

Thank you so much for all the help!

JD