Short story, I recently purchased a 96 Wave Venture 1100 from a Yamaha dealer on ebay. The PWC had an SBT motor installed in it, which was purchased in late January of this year. It had 0 hours on it when I bought it, and I had to break it in with the SBT Break-In oil. I did everything correctly, and there were no problems. I now have 15 hours on the motor, have been running 87 octane with Yamalube at a 50:1 ratio (per the Yamaha tech's suggestion), and have noticed lately that it is going through plugs fairly quickly. In fact, in the 15 hours of usage, I have gone through 4 sets of NGK BR8HS's. I gapped them to .024 which is Yamaha spec. I recently did an oil block off on the motor, and am premixing the fuel, because I do not trust oil pumps.
The last few times I have taken the ski out, I have noticed that it has a harder time starting initially....this was not the case when I purchased the ski a couple months ago. Even with the choke on, and brand new plugs, it doesn't even sputter. The spark on the plugs is a strong blue/white. When I do put fuel in the top of the cylinders however, it fires right up....sputters a little, then kicks in....so it's almost like a fuel vaccuum issue.
Well, yesterday, I took it out to the lake, new plugs, primed the cylinders to fire, all was fine. Took it out for a lap around the lake, and as I was bringing it in, it was idleing pretty rough, and shut off a couple of times on me. I brought it in, pulled the plugs. 2 of them looked ok, and the 3rd was really black, and the electrode on the bottom of the plug looked to have been bent so that there was no gap.
I stuck another plug in there, gapped it correctly, and it runs really rough, like it's only on 2 cylinders. I pulled the new plug, to see if it was bent as well, but it was ok, and still at .024 on the gap.
Now, when I go out and try to fire it up, nothing happens, no sputtering, nothing. Choke is on, battery is full, and there is good spark. It seems to me like a carb problem, or fuel delivery issue. I pulled the fuel pump off, took it apart, it was debree free. Took off the carb plastic cover, didn't see any foreign objects on the outside.
I don't know what the problem is. I have scheduled a service date at my local Yamaha dealership (not the same I bought this from) for Thursday, but would like to diagnose this problem before that. I don't have a repair manual for this ski, haven't been able to find them locally. Is there anybody with suggestions. I can't imagine it being carb settings....they were set by a Yamaha tech only 15 hours ago (usage), and it has just recently suffered in performance. I'd hate to think it's this new motor....
The last few times I have taken the ski out, I have noticed that it has a harder time starting initially....this was not the case when I purchased the ski a couple months ago. Even with the choke on, and brand new plugs, it doesn't even sputter. The spark on the plugs is a strong blue/white. When I do put fuel in the top of the cylinders however, it fires right up....sputters a little, then kicks in....so it's almost like a fuel vaccuum issue.
Well, yesterday, I took it out to the lake, new plugs, primed the cylinders to fire, all was fine. Took it out for a lap around the lake, and as I was bringing it in, it was idleing pretty rough, and shut off a couple of times on me. I brought it in, pulled the plugs. 2 of them looked ok, and the 3rd was really black, and the electrode on the bottom of the plug looked to have been bent so that there was no gap.
I stuck another plug in there, gapped it correctly, and it runs really rough, like it's only on 2 cylinders. I pulled the new plug, to see if it was bent as well, but it was ok, and still at .024 on the gap.
Now, when I go out and try to fire it up, nothing happens, no sputtering, nothing. Choke is on, battery is full, and there is good spark. It seems to me like a carb problem, or fuel delivery issue. I pulled the fuel pump off, took it apart, it was debree free. Took off the carb plastic cover, didn't see any foreign objects on the outside.
I don't know what the problem is. I have scheduled a service date at my local Yamaha dealership (not the same I bought this from) for Thursday, but would like to diagnose this problem before that. I don't have a repair manual for this ski, haven't been able to find them locally. Is there anybody with suggestions. I can't imagine it being carb settings....they were set by a Yamaha tech only 15 hours ago (usage), and it has just recently suffered in performance. I'd hate to think it's this new motor....
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