no power midrange up. easy start. perfect idle

[b1pig]

Ok guys. My wife's '07 is giving me fits again.

I pulled the carb and cleaned it since it is usually the culprit.... but apparently i did a great job of draining it/drying it last time we parked it. it was very clean.

here's the story. few weeks ago, i pulled the bike out, primed it up and fired it off for the wife. she rode it around the yard for 10 minutes then set off around our little town. she made it 1 mile before it fell on its face. she cant say it happened sudden or anything. she's a very reserved rider and doesnt jump out there and throttle it out of the driveway. she noticed it would not get over 35mph with her, so she crept it home.

i took it out. idle was perfect. but when you cracked the throttle open, the engine sounded "thumpy"..... on the intake side. no pops or backfires or anything. i thought it was starving for fuel so i parked it until i had time to pull the carb. did today. its fine. reset the idle mix to 2.75 turns (from 2.5) and added a thin washer under the needle to richen the upper range a tad.... although that needle doesnt really have much of a taper to it.

Result is same. thumpy intake noise when you crack it open. will NOT attain high RPM under load. first gear i held it to WOT and the rpm seemed to surge slightly and there was intermittent light popping in the exhaust, telling me unburned fuel may be dumping at that time?

I recorded a video, but the wind seemed to have covered the sound a bit. can ignition timing slip??? looks like i'll be pulling the valve cover and inspecting that timing chain friday.

warm start:


riding:

[b1pig]

nevermind. found the problem.

lash adjusters came loose... and fell out. completely. got lucky and found them on top of the head. put them back in. adjsuted valved. runs great.


anyone have a spare head? so long as the cam and the rockers are good... thats all i'm after.

[Water Warrior 2]

That was quick, glad you found the problem. Now your wife can go riding again.

[b1pig]

Just a short update.

Although the rockers were flat-spotted a bit, both they and the cam had smooth surfaces with no galling or anything. I just reassembled it and adjusted the valves. Running fine. And no noise. LOL

[Maggie]

Originally Posted by b1pig

nevermind. found the problem.

lash adjusters came loose... and fell out. completely. got lucky and found them on top of the head. put them back in. adjsuted valved. runs great.


anyone have a spare head? so long as the cam and the rockers are good... thats all i'm after.

WOW! So lucky they didn't fall down in the engine and mess everything up!