NEED HELP PLEASE! Diagnosing Issue with 1994 Yamaha ProV 150

[texahomankid]

Thats awesome to hear HH, I took my carbs off today and found that 2 of my slow jets were clogged and 2 were partially clogged. The remaining 2 were fine. I don't know if this would cause what Im experiencing but it will only help it having them unclogged. Didn't have a chance to run it as it is 1130 here. I have 6 brand new plugs going into it tomorrow, pulled them after I went fishing today (putted around the lake due to the issues, but Im an addict of fishing so I couldn't not go haha) 2 of the plugs in particular were really oily and probably fouled. Coincidently those to corresponded with the 2 slow jets that were completely clogged.. hmmm maybe Im on to something. Ill keep you posted, will be anxious to hear if that worked for you!

[texahomankid]

Hawgherder I do not doubt your knowledge one bit, however it idles this same way on the water as well, and a puff of smoke was an understatement on my part, for that I apologize, the word I was looking for was plume. Its an abnormal amount of blue smoke.
The only positive thing I find out of it is the glorious smell of 2t exhaust. It reminds me of my early days of racing motocross when I rode little 2t bikes. I will keep you all posted on what I find tomorrow.

**Edit, Hawgherder I did not see you posted twice, I found that I do have a voltage meter on my boat in my HUD, and that is how I figured out just today that my stator is working unless the meter is lying. In the driveway the voltage reads 12.6v while running voltage fluctuates between 14.4 and 14.6v. Keeping in mind that the tenths go up in increments of .2 so, Im guessing I it at 14.5v while running. And that Is what I thought that dial was for, mine was on the 4 setting so maybe if I switch it to 6 it might help something, who knows. I know that on alot of racecars that Ive worked on the tach is somewhat of a brain when it comes to rpm, as in it is what will shut the motor off if it senses that the rpm's are too high and sensors similar. I don't know if boats are the same but maybe, there is a whole mess of wires coming out of the back of the thing! Thanks for your input it is much obliged.

[headhigh]

It's no coincidence that your oily plugs correspond with your clogged carbs. Hope this fixes your problems.

(If I've told this story before, I appologize), but when I first bought my boat back in 2008 it had sat for a couple of years without being run. When I got it out on the water I quickly ran into issues very similar to what you are experiencing. I pulled the carbs and cleaned them pretty good and everything was better for a couple trips....and then the problems returned, so I cleaned them "pretty good" again. Well, again I ran better for a few trips and then the problems returned. At this point I just knew there had to be another problem. It was at this point that I spoke with Mr. Wayne Hayes who has worked on Yamahas for qute a long time. When I told him about my problems he just smiled and laughed. It was at that time he told me that EVERY issue he had EVER seen on the Yamaha carbed 2.6 liter motor was from dirty/plugged up carburetors. He told me to pull the carburetors off 1 at a time, completely disassemble them and soak them in carb cleaner OVERNIGHT before reassembling them. Well, low and behold, after I did this she's run great for the last 6 years. I hope this fixes my problems again. I'm at the point where I could do these carbs in my sleep!

[headhigh]

Tex, I just had mine out for a test run and she ran perfect! Hope you have the same luck.

[ChampioNman]

There are tests you can perform using a meter and the shop manual. 14.4 and 14.6 VDC is on the upper end of the voltage charge spectrum. I had a customers Pro V 150 that would run great first run or two then as it heated up it would develop a skip/misfire to it. Tested coils and wires. It ended up that the stator broke down after it warmed up. New stator fixed the issue. I hope you only have a carb issue.

[hawgherder]

Sounds like you need to consider a 10 micron filter if your carbs keep getting dirty.

[texahomankid]

Ran exactly the same. Im about to just put it in without the plug in and sink it.

Championman, how do you test it with a meter, I have an ohm/voltage meter but nothing more than that. Can I preform the test with that or will I need to take it in to someone?

HH the carbs clean helped with all the smoke while on the muffs, no blue smoke or puffs. As soon as I took it out on the water it acted the same sounded like it started missing again by the time I returned to the dock the blue smoke had returned.. Im at my wits end with this damn motor.

[hawgherder]

keep in mind that a stator has a high speed coil and a low speed coil. A defective low speed coil won`t let the engine run at idle. The high speed kicks in at aprox. 2000 rpm`s. So if you`re reading your battery voltage below 2000 rpm`s ( on a hose) it will look good. The Yamaha service manual doesn`t have specs to ohm the stator only voltage readings but I know that info is out there somewhere. ebasic power has ohms reading for Mercury engines but I am not sure about Yamaha. You could try disconnecting the Stator wires and check them to ground. They should never be grounded since the coils operate by induction. Also the voltage regulator/rectifier will cause the engine to bog at about the same rpm`s. The engine will act like it is not getting enough fuel to speed up and will be most noticeable under a load.

[texahomankid]

Okay so Ive got the carbs off and on a soak right now. When I unscrewed all the Fuel/air screws they were all different, bottom and top carbs were set at 1 3/4 turns out and the middle one was at 1 1/2 turns out. Does this sound normal. It is what the shop I took it too last fall set them too and it ran well for the few times I got to take it out before it got too cold for my likings. I thought that rather than the settings being the same by carb they were supposed to be the same in respect to each side of the engine?

[texahomankid]

Also could float height have anything to do with it? How should they be set?

*Edit
I just used my man intuition, engineering way of thinking (haha) and set them high enough so that it will fill the bowls, I figured that could have been part of my problem. Ive officially lost my mind and Im going over everything Ive checked a second time.

[hawgherder]

If the float allows too much fuel into the bowl the carb will flood. Hold the carb bowl up and the float should be about 1/4 inch up on the end opposite the needle. The needle should be 1 1/2 turns out to start with then adjust for best performance.

[texahomankid]

If the float allows too much fuel into the bowl the carb will flood. Hold the carb bowl up and the float should be about 1/4 inch up on the end opposite the needle. The needle should be 1 1/2 turns out to start with then adjust for best performance.

A quarter inch gap between the float and the outer edge of the carb or a quarter of an inch hanging?

[hawgherder]

With the carb held with bowl up the the float should be higher on the side opposite of the needle. Too high will cause not enough fuel for high speed running and too low will cause the carb to flood.