Sounds to me like your fuel pump quits pumping on you just for a little bit. I have had a problem like that but at lowers speeds like 35-40 mph. If ya got 110,000 on I don't think I would sweat it.

Funny thing.....Although my bike is stock, it was a persistent problem, surging and dying while warming up. Yamaha couldnt seem to find the issue or fix it for that matter. I stopped using the choke to start it, and began using a higher octane gasoline. Seems it does'nt like the ethanol in the lower octane fuel. Runs fine no problems now. used to go through plugs every 4k miles when I get my services done. Run crappy right before a service.

ghost_flamed wrote:
I stopped using the choke to start it, and began using a higher octane gasoline.


If you don't need the choke to start, especially on first start-up of the day, then you are too rich. Higher octane gas burns slower and will leave more carbon build-up. These are low compression engines and need only reg gas.

Yamaha told me that they ran it on their dyno, and stated that the stoic mixture is with in specs at 13.9to1. or something to that effect. The bike just wont run right on regular gas. Been like this since new. I run regular gas and it runs horrible. I run super and it runs great! I had mentioned this to yamaha service, but state they cannot fina anything wrong with it. I had in the shop twice a mont sometimes complaining of the fuel problems. They make a few adjustments and send me on my way. Didnt doesnt make a difference. I told him that carb is fukked. they won't listen. I kept getting told that this is normal condition with these bikes. Yamaha said they fixed it with the addition of f/j last year. what about the rest of us with the shitty/carbs??!!

An air/fuel ratio of 13.9 :1 is fine for cruising, but it would be too lean at WOT. Max tq is at 13.5, and wot you are better off somewhere around 12.8, the richer condition for wot is to help in keeping engine temps down and to prevent detonation. Has the float level been looked at? Too high could also cause low mpg's, and maybe that it's taking in gas too quick and engine can't burn it all causing a loss of power, likw flooding the engine. I'm really not sure on this, just throwing things up on the wall, maybe something will stick. I know the 1700 carbs the float level is higher than the carbs on the 1600 engines, but even lowering it to the 1600 float level, I don't know of anyone that has an issue with it either.

I told the dealer constantly to look at the carb and possibly rebuilt it. They wouldnt do it unless they can dupe the problem first....BUT IT"S THERE!!! LOOK IN THE CARB PEOPLE!!! They still refuse to do it. Now it's out of warranty and now I have to pay for it, that's not right. this is the second Yamaha I had carb problems with. The first was a V-star 650 that they had to replace because when it was getting rejetted, "a few parts came apart" they said. I tried to tell them there was something wrong with it. Oh well, I think I found a dealer that can look at it for me....but once again, I will have to pay for it. and it won't be cheap.

It's cheaper to buy the tools and do it yourself. The tech articles on the roadstarclinic are far more valuable than the dealers opinion. As a flat rate auto mechanic, I see this situation all the time. Example: A person brings there car in and tells the writer "My brakes make a noise when backing out of the garage in the morning". Then the service writer writes up a repair order that says, "check brakes". (useless huh?). Then, the customer signs the work order allowing the dealer to work on the vehicle. (If you stop there and make sure the repair order is written up correctly, the tech may actually know what your "actual" concern is). Now, the tech drives the car around the block, reports no problems found and moves on to the next repair order. Look at your previous repair receipts and see if that has occured to you. I bet it has. It happens with at least 50% of repair orders. The ones that do get serviced correctly are faults that occur all the time, in situations like this. Do your own due diligence and don't sign the repair order until your "actual" complaint is written on it. And berate the service writer for doing a piss poor job of addressing your (the customer...the guy that signs his paycheck) needs and concerns. Just some advise. It works with motorcycles as well as cars.