Exhaust popping

On last ride ('14 TE 310R) I noticed a lot of popping noise from the exhaust when I roll off the throttle. Also had difficulty getting it to fire with E-start - when it had been running (was warmed up) . It would start better with a good kick to the boot starter.

I checked the valves, expecting to find them tight. I found the opposite. Intake was .006 and .007. Ex was .008 and .010.

So, What to check now? I have read on some posts that the ignition may sometimes need to be re-mapped ? I had mine put in full power mode 2 yrs ago. Also unplugged the exhaust and intake at that time. Do those little centrifugal de-compression gadgets on the exhaust cam ever malfunction? Bike has 2600 miles of mostly dirt dual sport riding.

Suggestions welcomed

well, if the deceleration popping is a new thing, look for something that changed (we're suspecting it's lean so look for air leaks first).

The vacuum port on the right side of the manifold should be capped or have a good hose on it. The manifold bolts should be tight, hose clamp too. The throttle body and injector should be inspected (for cracks, or loose maybe). The exhaust header bolts (or was it nuts? CRS- but they're 14mm) need to be tight. Didja change the spark plug- if so... is it loose? is the catalyst removed?

next, maybe your air temp or cylinder temp senders are bad (this is a WAG; I don't have any direct experience)

btw, the I thought those specs for the valves were tight? shit, gonna hafta look it up sometime. but IIRC you wanna be on the tight side for easier starting (at least on the exhaust with the auto-decomp).

edit: whoops- Noobee got in 9 mins before me. way to go!

Mine will pop if header is leaking where it meets the head.

I checked the bike: exh flange is tight, intake bolts & clamp tight, vac port still plugged. Catalyst removed. on last ride, I did have left fuel valve closed. I think it would get enuf fuel thru one valve, until fuel level gets low. Spark plug is brownish grey on the metal. The ceramic is tan / beige. Does not look like lean running to me. In the past, I read some posts indicating that this model year had some flimsy valves installed, and would begin to warp. Has anyone experienced this? What are the early symptoms - or is it a sudden failure?

The two petcocks are just to transfer gas from one side of the tank to the other (and are just about useless IMNSHO). if one is off, it's the same as both off... and has nothing to do with your problem. I run with 'em off 100% of the time.

your plug actually sounds just a tad rich (FI sparkplugs are typically fairly white)- I'm not sure how to interpret that.

Valves: IIRC, the '14 went with SS valves, not Ti, and have no issues that I have heard of.

Did you change you exhaust can recently? does it need a repack? what did the injector and throttle body inspection reveal?

hell, maybe it ain't an air leak... timing change? flywheel lose? ding in the header?

hows it run? any different?

Couple thoughts.....

Go get a can of sea foam and run 1/2 can through a tank of fuel.

You might be attracting some water in fuel from humidity?

Have you lined the whole underside of your tank with heat shield ?

Bike before heat shield would kinda boil and yes popped more.

If you don't mind paying lil extra. Trash that ethanol fuel and use VP racing VPR fuel.

Mine runs awesome on this fuel. Better throttle response etc..... No worries of fuel going bad.

I've tried even going higher oct on some VP fuels and bike runs worse.

Also, at some point check your flywheel key. Last time ck mine it was starting to shear and flywheel moved lil.

Also, good time to clean sprag bearing gunk, lap flywheel on crank and use high temp sleeve retainer.

Also, you want to check stator bolts are not loose. Use red loctite on them.

The bike ran fine, except the popping and hard starting. The bike still has the factory , goobermint approved muffler on it - with catalyst removed. Do these street legal mufflers need repacking like the aftermarket pipes?
I will try shimming up the loose exhaust clearance (.010") and see how it runs. Then check flywheel. Do these FI bikes have a universal diagnostic plug in port like autos? r

A good way to check for cracks and air leaks is to spray a little starter fluid around intake area if you notice a change in idle very likely you found your problem.

Did you end up finding cause MZee? I have same issue with the popping.