Help please - RMZ-450 cutting out when idle

[carlins_leap]

Morning all,

 

Great forum - I am hoping some of you good folk can offer me some advice please.

 

My bike - 2016 RMZ-450

Issue - Bike starts 1st/2nd kick with choke, but for the first time I noticed some small backfiring while waiting a mo for the bike to warm up.  On turning choke off, the bike cuts out unless I give it some throttle.

 

Potential causes (I think)

There are a couple of things to mention:

Firstly, I last used my bike in Feb 23 but had to leave untouched for a while because of ill-health.

The fuel tank was full when I put it away.

I asked via a friends brother mechanic whether he thought this fuel would be ok to use and because he advised it should be ok, I didn't replace it prior to using (or attempting to yesterday)

 

Secondly, on the way to the track yesterday I had a mishap on the VERY bumpy road leading to the track...and the bike toppled off the trailer.  It wasn't upside down, but the wheel stayed on the trailer and the bars hit the floor - it was slanted down that way for a couple of mins whilst I sorted it out.

Once in the paddock, the only damage I could see was a shredded handlebar grip and a scuffed plastic.

 

I am a complete novice, so I am struggling for ideas on where to start with troubleshooting.

Someone suggested a full carb clean because of the old fuel...but I wanted to to ask for any more opinions before I give it my best shot at fixing...

Any advice would be massively appreciated.

 

Thanks

Steve  

[Mississippi Bullfrog]

First thing I'd try is to add fresh fuel. It doesn't go off as badly as some people say but if you put E10 in it then with carbs it can be a bit iffy on choke with old fuel. 

 

If the problem is only on cold start and otherwise it runs OK it can't be anything major. 

 

Backfiring could just be unburnt fuel then getting ignited in the exhaust.  On choke you're using a rich mix, if a stroke doesn't ignite and chucks that rich charge into the exhaust the next firing can make it go pop.