Hard to start and backfires like a gun. Griz 700

[TRACKSIDEDOWN]

07 griz 700, was running fine on acreage, now very hard to start and when it does you have to keep on throttle and it back fires like mad lol. Fuel pump cycles with key on/off. Wires around stator, which had been replaced last sept, look good. Airbox is clean, no mouse nest. Reverse override has been bypassed and hard wired. Any point of direction is appreciated. Thanks! It does have a fuel box added. Would that cause grief?

 

[Ron H]

First thought how old is your fuel?

 

[maierch]

Check the valve clearances. Tight valves can cause hard starting.

 

[the_real_wild1]

How many miles on the machine? Remove the "fuel box" and try it to rule that out.

 

[Megrizzly]

A year ago, my 07 had hard starting problems after I trailered it during late hunting season and in the winter. It would crank over normally, but wouldn't start and would backfire as well. Found out it was a faulty fuel pump relay. If I left it on the trailer till the next day or tried to start it long enough that the relay would warm up. The nytro also had some issues with the same relay.

Your problem I think is a lack of fuel and It could possibly be a faulty fuel pump relay that is having additional weird issues because of the fuel programmer. Disconnect the fuel programmer to see if there is any difference with the issues. Also install a new spark plug.

 

[whoDEANie]

Have you dried pulling the diagnostic codes? You can also check things out in a little more detail with diagnostic mode. I just found a link to an on-line service manual. Start at page 277. 07 08 Grizzly 700 Service Manual

 

[TRACKSIDEDOWN]

Fuel is less then two weeks old.engine has 1000 k on it. Rebuilt last year, could be tight valves. Work is getting in the way of doing a good check over. Thanks for the input guys!

 

[imdoo'n]

Best advice was disconnect the fuel programmer, have you tried doing that yet, those things are usually the problem, Always eliminate the easy things first, and just because fuel is only 2 weeks old , just don't mean it's any good!

 

[arff]

Try this...

 

[Ron H]

......well.....not to sure, bout all I can add now is some mornings I'm hard to start and occasionally backfire...

 

[the_real_wild1]

......well.....not to sure, bout all I can add now is some mornings I'm hard to start and occasionally backfire...

"Some" mornings??? You got that half right.

 

[butters]

Vent line on fuel cap plugged? Seen that before.

 

[neilsleder]

Timing chain jump a tooth?


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[Xfmontana]

Try a new spark plug? Worked for buddy, nice quick fix. He still can't believe it worked lol


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[somethingnuw]

Fuel is less then two weeks old.engine has 1000 k on it. Rebuilt last year, could be tight valves. Work is getting in the way of doing a good check over. Thanks for the input guys!

mine use to bike fire a lot... i didn't realize your not suppose to run premium fuel through them... i thought i was doing good for the machine and it ran like crap and the warmer it go the harder it was to start... as soon as i'd lay of gas it would back fire hard... thought i blew my exhaust of once... back to 87 cheap grade fuel and it runs top notch... hope its that simply for you... i ride a 2012 fi... maybe it's different but worth a try

 

[whoDEANie]

mine use to bike fire a lot... i didn't realize your not suppose to run premium fuel through them... i thought i was doing good for the machine and it ran like crap and the warmer it go the harder it was to start... as soon as i'd lay of gas it would back fire hard... thought i blew my exhaust of once... back to 87 cheap grade fuel and it runs top notch... hope its that simply for you... i ride a 2012 fi... maybe it's different but worth a try

I run my 2009's on premium ONLY. Sometimes, th ey run better than other times, but when they're behaing like crap, it's never been the fuel.

For me, any issue like that has been electrical. The worst cases have been the cable stay right by the stator that the wires curl around before going to the other side if the bike - it chews through the jacket pretty cleanly and you can barely even notice it unless you give the cable a tug and strsighten it out. I'd definately check that first.

When I was poking around trying to find that issue for the first time, I alsi found loose bullet connectors in the wire hsrness. The section of wire harness that runs between the air box and cvt exhaust is wrapoed up and has bullet connectors in there. When I unwrapoed mine, the connectors just fell apart. Definately another place to check.

Throttle position sensor is supposedly another bug culprit for that kinda behavior. It's easy to check - the link I sent you earlier shows how.

I've heard fuel pump issues causing this issue as well. You would have to pressure test your fuel system to eliminate it as a cause.

It was also suggested to me to test my injector. On top of the diagnostic you can do, you can also pull it and ensure it's spraying corrcetly.

I get the idd backfire issue, but I've only seen the rapud backfiring and starting trouble you describe two times and it was that stator wire both times.

 

[RZR101]

Sounds like may be an intake leak to me, between the throttle body and cylinder.

 

[arff]

Sounds like may be an intake leak to me, between the throttle body and cylinder.

I figured you would say a broken axle.

 

[RZR101]

I figured you would say a broken axle.

Knock on wood, all axles intact so far this year.

 

[Corwyn]

I just had an issue with my 11 brute, was the a weak fuel pump, maybe try a pressure test.