2.6l Yamaha 2 stroke starts and idles fine intermittantly chugs and dies

Hello my name is Noah this is my first post or thread here. I appreciate a site like this and hope someday to know the answer to someone elses question. I am new to tournament bass fishing and am very excitied about competing more frquently. I picked up an 84 skeeter 175 that looks to be 80 percent restored with the engine and symptoms decribed below. I used to R&R transmissions and worked a deep sea boat out of channel islands harbor for two summers(including dry dock).

I have a yamaha 2.6 liter The original stickers are gone half of a tag is missing. One tag says YAMAHA V-6cyl. 2596cm3, the other says yamaha 22 and gets cut off. That tag also says 6g7 L 3 then cut off. I have to crank the heck out of it to get it to start the first time at the ramp but after that it lights off fine. It runs up great through all rpms until I stop to for a while. Then sometimes and more frequently as the day gets longer the boat will start but only idle. If I crack the throttle it will die. I have tried pumping the fuel ball and pressing the gas and it still wont go. But everytime it ends up suddenly being back to it's old self again and ready to fly. I suspect it is an ignition issue but I am lost for where to start.
Thanks ahead of time for any help on this, I'll do my best to answer any questions I may get thoroughly.

Re: 2.6l Yamaha 2 stroke starts and idles fine intermittantly chugs and dies

I found another thread on another site that talks about having this problem with a bad stator. Does this souund right?

Re: 2.6l Yamaha 2 stroke starts and idles fine intermittantly chugs and dies


This is what I found on the 6G7 you posted. http://continuouswave.com/whaler/reference/yamahaModelGuide.html

Need to find a Service manual for your motor and test peak voltages with proper equipment to see if they meet spec. if you think it is loosing spark

Compression, spark, and timing are all easy to test and if they are all good then you are left with a fuel problem

Re: 2.6l Yamaha 2 stroke starts and idles fine intermittantly chugs and dies

Thanks. I tested compression 200psi give or take 5psi. Just had carbs gone through and they checked out. Timing I'm not sure on. I will follow your link and see where it gets me. Thank you very much.

Re: 2.6l Yamaha 2 stroke starts and idles fine intermittantly chugs and dies

never seen 200 PSI on a 2 stroke before.

The link was just where I found what I posted, it is a link to outside US market motors

Here in Us they list a 220 in 1985 I think and then a 225 in 86 or 87 so I am thinking you have a 84 to 86 motor, but not sure which year to help you find a service manual

Re: 2.6l Yamaha 2 stroke starts and idles fine intermittantly chugs and dies

typo on the 200psi. 95-100 on cylinder pressures. Got to multi tasking at work and posting here. I sure appreciate the help tomorrow I am going to try to get it out on a local pond and do a couple hot laps. I'll bring a timing light, multi meter and a few other basic tools to see what more info I can gather. I have a tournament from the 6-7th next month. I'll go whether it is running better or not but would sure like to have it running right.

Re: 2.6l Yamaha 2 stroke starts and idles fine intermittantly chugs and dies

The timing light will also show if you are loosing spark to different plugs by moving it to the different plug wires while problem is happening

Re: 2.6l Yamaha 2 stroke starts and idles fine intermittantly chugs and dies

Ok after a week of strep throat and work I got the boat pulled out to the street. Put my newly pos back out when I pressed the clutch on my truck but still managed with the spasms and all to move forward. I fired it up and let it idle with the muffs on. Took timing light and hit all six cylinders. The right bank to me or the one with the cylinder that is most forward or high on the engine had spark and the left bank had none. then check right again and it had none then back and forth. started to not trust the timing light seemed like the engine was changing which cylinders to run on and bouncing around. Is this possible? Most of the time it seemed the drivers side of the boat kept it's spark while the passengers had none for a little bit then all of a sudden all cylinders were firing. Kind of goes right along with the problem I have been having on the water.
Also I am having trouble finding the manual to this seems like I found it once and now Yamaha doesn't track back that far anymore. the one I did find was some off brand not sure if thats a good one or not

Re: 2.6l Yamaha 2 stroke starts and idles fine intermittantly chugs and dies

found the manual again just need to order it I guess. price seems rediculous for a print out

Re: 2.6l Yamaha 2 stroke starts and idles fine intermittantly chugs and dies

Sounds like you will need to take peak voltage readings with the proper meter or use a DVA adapter to see what is going on for sure

Re: 2.6l Yamaha 2 stroke starts and idles fine intermittantly chugs and dies

I ordered the manual and I guess I will google dva adaptor. I found a buy it now on ebay for an original manual for $65 to the door should be here next week. Are you talking voltage from the coils?

Re: 2.6l Yamaha 2 stroke starts and idles fine intermittantly chugs and dies

From charge,pulsar, and lighting coils to the CDI or ECU and then to the ignition coils

Re: 2.6l Yamaha 2 stroke starts and idles fine intermittantly chugs and dies

Well went and fished my tournament and the issue never reared it's head. I had a pile of other issues but thats another thread maybe. I received my manual in the mail. I will be reading into everything on that it will more than likelly be mid winter before I get to tearing into it. Thanks again for the help so far I'll be back on this thread after I get the data collected