My pig has lost its grunt - help!!!

Took my 2003 650R off road for the first time proper on Saturday - (which was awsome I have to say!!). Went up a mountain trail - loads of dust/gravel/rocks. However when got back to the tarmac, I noticed a real lack of power/torque. The engine revved ok but seemed real flat, only getting about 65% power - before I was pulling 3rd gear wheelies and getting 100+ top speed no problem, but after off road, was struggling to get up in 2nd and max speed about 70mph! On trip back home, thought the engine was making a bit of a hiss/tick noise. Had a quick check round it at home and maybe I was being paraniod but thought the engine was more rattley/noisy than usual. Checked the coolant level which was OK and it was due a oil change so I done that there and then. Again maybe being paranoid but after running engine to check oil level, there were loads of small air bubbles on dipstick which I never really noticed before.

I checked the spark plug cap but it seemed ok, but still need to inspect the plug itself (althhough I put a new plug in, plus an oil/oil filter change when I got the bike about 500 miles ago). Hoping that it might only be a bit of dirt in the carb which a clean out should sort - but I would have thought the bike would tolerate dust gravel a bit better.

Won't get a chance to look at the bike til Wednesday so does anyone know what might be causing this or what to be looking at first - or reassure me that I'm not facing an expensive engine rebuild, since everybody has told me the engines are bullet proof!!.


Is your air filter clean?

is the clutch slipping?

Pig engines ARE bulletproof. Air filter sounds suspect.

air filter isn't spotless, but didn't look too bad - it's a sponge washable one which I had cleaned when I serviced the bike when I got it. Its def not spotless now but you can still see the 'fresh' filter oil in the sponge - certainly not as dirty looking as when I washed it the first time. However for all I know, just becasue it looks clean might not necessarily mean its not clogged up with dust. I'll be delighted if this is the problem as I'm more worried of a more serious engine prob. Is this a common problem, since the bike is so capable long distance off road, would have thought my wee blast up the mountain trail would be no prob since wasn't a great distance covered!!??

Oh forgot to say, that no, the clutch is not slipping

Check your valve clearances.

Did you leave the choke on.

Sounds like the valve haven't been adjusted and the intake are way to tight.

Cleaned the air filter, but made no difference. Looks like the advice is pointing towards checking the valves next. If its the valves, would the loss in performance be so sudden? - it starts easy enough . Beginning to think the off road bit might be just coincidence, and might well be something more serious, hope not!! Will check valves tomorrow when i'm off, and might as well check carb/jets and spark plug,. Any other easy checks I should do while I'm at it?


PS No didn't leave choke on!

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