XR650L Engine Brake Backfire

Hello everyone,

I have a 2004 XR650L, mostly stock.  Recently it has started behaving strangely when i engine brake (as i do all the time).  When I engine brake for several seconds or more, and then open the throttle, the whole bike bogs down for a second, then backfires through the exhaust very loudly, then accelerates. Up until now the bike was running fine.  The only thing i've done was install the smog block-off kit about 2 weeks ago.  Does anyone have suggestions as far as potential causes or solutions? 

Thanks, David

Update:  Found a smog blockoff cap was missing on the bottom of the carburretor.  Replaced with a new one.  Time to test!   :ride:

Problem resolved... thanks for responding... nobody.  :smashpc:

Hi Barbarianbug - your last response is a good way not to get any help in the future - remember some members work and some live in different time zones - be nice to the members and they will be nice to you and they really are a fount of knowledge....  Pleased you found the problem.

u can eliminate that cap and tee altogether with a longer hose

Yeah I was joking but I guess that doesn't transfer over too well on the computer.

The cap I replaced was on the bottom of the carb, not the one with a tee. Is that the same one you meant?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now