I took my '07 Sportsman 700 out for the first ride of the season today. Temp was in the mid 80s, mostly sunny. I had ridden about 30 miles w/o any issues. I was accelerating slowly after being at a stop and the machine lost power and died. The engine turned over fine when I tried to start it, and would sputter/fire a little, but would not start. I waited about 10 minutes, and then it fired right up and ran just fine.

I was able to ride another 15-20 minutes, and it did the exact same thing (died after accelerating from a stop). Waited about 10 minutes, started it up and rode about 30 minutes and the exact same thing happened again. Waited 5-10 minutes, started it up and I made it back to the truck (probably about a 10 minute ride) and put it on the trailer.

I've owned this machine since new and it has about 1500 miles on it. This is the first time I've had any problems with it and I've used it numerous times on much hotter days.

Any thoughts on what's causing this?

Thanks for your help.

 

If you have access to a fuel pressure gauge and adapter to fit the fuel rail, the fuel pump must hold 39 psi with out any drop in pressure. This could be the problem,losing pressure when hot,OR if it checks out ok it could be a short or internal broken wire in the small t bap or tps harness or even a small bare wire from the crank position sensor harness could stop it dead in it's tracks if the wire intermittently touches the engine. Also look at the "sticky" section above this one on the 700 and 700 efi problems, the most common problems on efi machines,the small wiring and connectors going to the sensors and better harness repair kits offered.Sensors other than an occasional faulty crank position sensor are not normally problems,just the wiring.

 

Thanks for the reply, OPT.

My machine isn't exhibiting the symptoms described in the T-Bap wiring thread, but it looks like it would be a good idea to replace this harness anyway, so I think I'll pick one up even if this isn't the problem. Is the crank position sensor wire part of this same harness, or is it a different harness?

I don't have an EFI fuel pressure gauge kit, but I think a friend of mine has a kit that will work. Is the fuel rail connector on the right side of the machine under the removable panel below the fuel tank? Do I just turn the ignition to the "run" position to check pressure? How long should I keep the key on for the test?

What struck me as strange about this problem is the machine runs smooth and has normal power while going down the trail. The only time the problem surfaces (at least so far) is while accelerating after being at a complete stop. And it doesn't happen every time I stop and accelerate. If it was the fuel pump or T-Bap harness, wouldn't the problem show up more consistently? I was wondering if I was experiencing some sort of vapor lock issue.

 

Cps is at the right side of the engine,the harness and connector run under the throttle body. This where we've found bare wires shorting out again the engine. The fuel rail is just behind the injectors,the shrader valve has a black cap on it. Dirt Cheap Yamaha, Honda, Arctic Cat & Polaris OEM Parts & Accessories – Cycle Parts Warehouse
You can make sure the tank vent is open,just pull the line off the fuel tank valve and blow through them. If you suspect either of the check valves are a problem,leave them off and see how it runs. Dirt Cheap Yamaha, Honda, Arctic Cat & Polaris OEM Parts & Accessories – Cycle Parts Warehouse

 

I appreciate your help, OPT. I won't get a chance to look at anything until next weekend, but at least I have a few things to check out now. I also ordered a T-Bap wiring harness tonight, just in case. If nothing else, it appears to be a good preventative maintenance item.

 

I wanted to provide a status update on this situation. Because I didn't have access to a fuel pressure gauge that would connect to the ATV, I started with installing the T-Bap wiring harness and nothing else. Since doing this, I've put on about 250 trouble-free miles, so I'm confident the harness was the culprit.

I think the important thing to note is I didn't have any of the symptoms listed in the sticky thread for the T-Bap harness, yet this appeared to resolve the problem.

Thanks again for your help, OPT. I would have never figured this out on my own.

 

Harness problems were what we dealt with the most on efi machines. Sometimes codes don't show up,symptoms may not always indicate a harness problem..Hope it keeps running good for you..