Quad bike backfiring

[KK6610]

Yamaha grizzly 450 started backfiring when decelerating this morning....scares me and the dog! To be fair it's done it before, but not for the last couple of weeks. Only thing I did differently this morning was fill it up with petrol from a supermarket filling station whereas last couple weeks been on Shell petrol. Anyone else find this with "cheap" petrol? Perhaps more importantly does the bike backfiring do it any harm or suggest an engine problem?

 

[roscoe erf]

Check your spark plug had a duff one. In my yamaha which caused a backfire

 

[Partstech]

Kawaski`s used to suffer the same symptoms when the ignition coils were starting to break down

 

[Dave6170]

Our 1 was sooking air between carb and air intake. Rubber pipe cracked.
Dirty carb, too much fuel? does it idle?

 

[pycoed]

Backfire on deceleration is most likely to be a hole in exhaust allowing air into the hot exhaust which then ignites. If you're unlucky it'll be a burnt inlet valve at a guess.

 

[DrDunc]

The yam grizzly's are prone to it. Don't let folk guessing there's big damage panic you.

Change the spark plug and clean the air filter.

Also check you haven't inadvertently moved the choke lever

 

[Jack Strong]

Don't worry about it it's most likely bad fuel as it used to happen on our old 660 and the 700 we have now especially when we used supermarket fuel.

 

[KK6610]

Thanks for the replies folks, hope its just the fuel, but will get a new plug and air filter onto it... Save the dog'snerves!

 

[tmb]

Back fire is caused by un burnt fuel new spark plug check the ht lead and air filter that should cure it

 

[itsintheblood]

Honda's are prone to this to , almost certainly a exhaust fixes it in most cases, will be interested on how you get on?