Left yamaha flushing connectors disconnected underway

The first thing I did was check for spark by turning engine over while plug and cable are connected and grounding it on the motor. I saw spark.

I think you still have a good idea, I might as well replace the plug assembly to confirm this is not the issue before digging into the carbs. It only takes a few minutes.
 
CDory23":1ht1158l said:
Ok, So i decided to check for spark and all plugs have it. I then decided to pull plug wires with motor running to see how it would effect the performance since its acting like its only running on 2 of the 3 cylinders. Well when i disconnected the plug cable to cylinder number #1 it made no difference in the engine running. When i pulled #2 or #3 the engine would die instantly. So the engine is only running on #2 and #3 cylinders.

The good thing about twins is when your working on them you can test theories on the other motor. I did the same test to the other motor and when one plug was pulled it ran exactly like the motor with issues, on two cylinders.

So I know I have spark, I'm thinking at this point its safe to assume that the #1 carb is not giving the #1 cylinder any fuel. Does that sound right? I did unscrew the bowl drain and fuel came out of the #1 carb.
Click to expand...


OK you have spark at all plugs?

I don't know how you tested it but an inline spark tester is useful. This will test the ignition system is functional.

If you think it is no gas (blockage) then locate the screw in front of high speed jet, and check for dirt, debris causing blockage. usually it is located on lower front of carb float bowl. Check the manual for the location. Priming gas through it should clear it
 
Thanks,

There is no way to take the bowl off without removing the whole carb manifold off as the carbs are all stacked on top of each other. At this point since there is a member here with the same motor who has re jetted his carbs and had good operation since I'm going to pull the carbs, rebuild and re jet much larger and hope this solves this carb issue.
 
CDory23,

It sounds like you are getting close. I would sure start with that #1 cylinder carb, and make sure it is all clean, and the jets too. Then be sure they are synced when you put it back together. (I learned that from my mechanic.) I hope that works for you.

Harvey
SleepyC :moon

1_10_2012_from_Canon_961.highlight.jpg
 
I hope I'm getting close. Yes I understand the carbs all need to be synced after the cleaning. I planned to take them to the mechanic to have this done when I was finished in less you are saying there is a relatively cheap/easy way to do this yourself. Please advise.

Thanks!
 
CDory23":1vlsemqf said:
I understand the carbs all need to be synced after the cleaning. I planned to take them to the mechanic to have this done when I was finished in less you are saying there is a relatively cheap/easy way to do this yourself. Please advise.
Click to expand...

When I bought my 22 the 2002 Yamaha 80 had obviously been sitting (50 hours, non-current registration, boat stored in a building). The seller (who was not the owner - was a dealer) tried to get away with just a heavy duty carb cleaning, but a sea trial showed that was obviously not enough. It would run fine until about 1500 rpm, and would then start to miss. I offered a price that would account for my having the work done, and then after taking possession promptly had a good Yamaha shop rebuild all four carbs (in addition to catching up general service items). Ran like a charm after that.

Others have mentioned this, but whenever I store the boat (I tend to go out for longer cruises and then store the boat for more than two weeks), I drain the carbs. It takes less than five minutes and is a very small percentage of my "put away" time. This removes fuel that just running the engine dry does not take care of (I do that first though, to minimize what I'm draining). I just crack four screws and hold a paper towel under each of them to drain the carbs. The bottom one is a little tricky to reach but not bad.

I have never tried to synch carbs, but I noticed that Dora~Jean's album has a good pictorial of it. He has twin Yamaha 80's of our same vintage, too. Here is a link to his "engine maintenance" sub-album:

http://www.c-brats.com/modules.php?set_ ... _album.php
 
There is a real solution to your carb problem... rebuild them and re-jet them to a much larger size.... I had to look hard but I found the same series of jets used on earlier 2 cylinder Yamaha carbs...only the jet size is much larger...I installed these and my motors start, run and give better economy...amazing ... I think Yamaha jetted the carbs too tight to get that emission rating without thinking about the possibility of reliability problems... as I understand it the same motor when used on a daily basis never gives any problems... only motors that are left wet for long periods of time have carb problems. I now drain my fuel and carb bowls before the boat sits for any length.

Joel
SEA3PO
 
The tool used to sync carbs is expensive..but I found an inexpensive way to build a first class tool.... easy... 1st. on EBAY buy liquid filled vacuum gauges that are made in China...they are worthless.. the reason is that they are in a measurement that no one but a China man understands...but who cares what the actual number is...what you are trying to do it adjust all 3 carbs to the exact same point...and they work perfect for that... just don't try to understand the numbers...will make you crazy... glue 3 of the gauges on a stick one over the next.... the neat trick is the nipple that screws into the manifold is a small metric thread.... easy...buy 3 mig welding tips...they are the same metric thread and will work perfect as nipples in the manifold... about 4' of clear hose from Home Depot and yer finished ....

You need to disconnect the throttle linkage to adjust the three carbs...once you get the exact same vacuum numbers on your gauges you adjust the linkage to fit the carb holes... not the other way around.. and your done..

EASY' and the cost is about $30

Joel
SEA3PO
 
Joel,

You have been extremely helpful. I ordered the exact same jets you have and am waiting for them to clean/change jets in the carbs.

Thanks Brent for that link. That would be an easier option for me opposed to building one and saving $40. I actually looked up a youtube video on syncing carbs and saw somebody using that exact product. I think I will purchase that to set off the cost of taking it in for the sync.

Thanks all. Its a waiting game now.
 
The answer to that is sorta a yes and no..... that gauge will work...but it might make you crazy.... what happens is those gauges are not liquid filled...and the needles move so fast that they are hard to get an exact number at idle...fine at high speed but idle they will be bouncing around fast....

What makes the home-made unit better is the gauges are liquid filled...and dampens that jumping around...makes it much easier to read...that is the difference between a $75 tool and a $350 tool.. I like the $30 best.

Joel
SEA3PO
 
I was just thinking...why not just borrow my tool ?? it's not like I use it every day.... it will fit in one of those all you can pack boxes that cost $12.95 one way...so round trip would cost about $25... just about what it cost to build yer own...but if anyone would want to use mine I sure will loan er out..

Joel
SEA3PO
 
I could also glue another gauge on the stick for any of you'all that have 4 cylinder motors....it's just shoe goo...

Joel
SEA3PO
 
Thanks for the offer Joel,

It turns out the maintenance shop at my work has a quality carb sync tool I can borrow so it solves the issue for me.

Has anyone done or considered changing out the fuel line in the motor itself? If I get these motors running good again I"m going to change out all of my fuel lines in the boat even though they look to be in good shape just because they are 13 years old now.
 
CDory23":100jgxb3 said:
Has anyone done or considered changing out the fuel line in the motor itself? If I get these motors running good again I"m going to change out all of my fuel lines in the boat even though they look to be in good shape just because they are 13 years old now.
Click to expand...

I did. As you are planning, I put all new fuel lines/hoses in my boat when I first got it. Actually, I got new tanks too (was in the right place at the right time to make it easy). While I was at it I also replaced the section of fuel line in the engine that runs from where it enters the motor (after the external line with bulb) around to the internal fuel filter. It was something like 12" of hose. The boat had been sitting prior to my buying it (had to have all four carbs rebuilt), and I just wanted to make sure it was all clean/new, and that the fuel lines were all the correct ones and as "modernly" ethanol resistant as possible (although I still try to run pure gas). I have a Yamaha 80.
 
I used A1 fuel feed hose. It
has a fire resistant cover; is designed to have fuel in the hose at all times. Least permeable with highest fire resistance.
 
BrentB":1pltjeqh said:
I used A1 fuel feed hose. It
has a fire resistant cover; is designed to have fuel in the hose at all times. Least permeable with highest fire resistance.
Click to expand...

Good point to mention. A1 rated hose is the correct designation to use for most fuel lines. Fills can be A2 rated (and I believe vents as well, but I'm a bit rusty on that without looking it up). However, within the A1 and A2 designations, there is still a variety of options of specific hose model number. I used all Trident brand hose, but there are other good marine hose manufacturers (Shields, Vetus, etc.). Going by memory (when I chose the various hoses I temporarily immersed myself in their hose catalog, but that's been a couple of years ago now)...

1) Fill hose was Trident #329 (type A2). #329 is a corrugated (Michelin Tire Man look) type hose, which I used because it would made the necessary bends more easily -- without putting excessive pressure on the plastic filler necks of the fuel tanks (especially the port side fill, which doglegs around the lazarette).

2) Vent lines were another Trident hose, but I can't remember which one right now.

3) I then bought some Trident #305 ethanol resistant fuel hose for the outboard supply lines (grey in color; was recommended for outboards), but found it very "thin" and prone to kinking. It just didn't give me a good feeling because of the way the supply lines in the splashwell need to move). So I ended up using another Trident hose (#365, I think, but might have been #319) that was quite a bit thicker, black, and not prone to kinking. I used this for all the supply lines, both from the tanks and in the splashwell.

4) But I did find a good use for the thinner grey #305 hose, which was to replace the main fuel line inside my Yamaha 80 (from where it enters the engine cowling to the internal fuel filter). The thicker hose would never have fit, and kinking wasn't an issue as the line is "guided" over the whole path.

The Trident hose catalog link is here: (2.7MB download):

http://tridentmarine.com/wp-content/upl ... atalog.pdf
 
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