Engine Knock Beta Rev 3

[mil]

Hi,

I've been riding alot of fire roads and trails recently and riding the bike in 5th gear at some speed. When I roll off the throttle there seems to be a knocking or clunking that I can;t place. The bike runs fine but don;t like random noises. Could this be the piston? It's an 04 model and I bought it 6 months ago. I don;t know if Piston/ ring hase been changed- would this be recommended? How easy is the job and cost of parts?

Many thanks for your help.

Mil

[barrybaines]

Just done the rings on my '04 (after it chewed it up and spat it out!) easy enough too do although a bit costly for what you need!

[paul w]

if the engine pings or knocks on the overun after you have shut off, i would recommend a de-coke, i do my bike twice a year at least. remove the head, barrel and piston, scrape the carbon off with a razor blade and the finish off using a scouring pad and brake cleaner. also remove the rings and clean out the ring grooves. works ever time on my bike. hope this helps.

[totalshell]

if it sounds like somebody hitting your cylinder head with a toffee hammer and probably always under the same circumstances then almost certainly one of three cheap things will cure it,

A, use super unleaded

B, put a 32.5 pilot jet in,

C, or take the head off and decoke the top of the piston as described above.

the first will cost you a fiver and take no time, the second 8 quid and remove the carb and replace the jet 1 hour max, to get the head off ( and the rest to actually get at the thing) is going to take a leisurely morning and the price of a head gasket another few quid.

not likely to be your rings..

Edited March 16, 2007 by totalshell

[mil]

Thanks for the replies everyone. I will strip it down and de-coke and hopefully that will sort the issue.

Is it necessary to replace the head gasket when I strip it down? Or will it seal ok with the original back in?

Cheers fot your help

Mil

[paul w]

you can re-use the old head gasket , use a very thin smear of good quality "instant gasket" too much will block the water passages in the gasket. really the best practice is to use a new head gasket, the base gasket if in good condition will always "go again". get the spanners out and good luck!

[02-apr]

Has there been an alteration to 04 and later? I had to pivot the motor down to get clearance on my 03 for the barrel to come off - the lug for the top engine mount hit the underside of the "tank". Was tempted to "ease" the tank a bit but I don't think it's feasible with what is the strongest alloy tank in the world. Don't ask about the major operation to get the sumpguard bolted back, I wouldn't want to do that again. Even worse than the old MAR with its fine pitch theads.

[barrybaines]

I did turn the barrel slightly too gain clearence I admit!

As for getting the sump guards on Most probably the hardest easy looking job going!

[dougie pumpkin]

On my 04 mont . I used a G Clamp and ratchet strap to Get the Sump Guard back on . it took 5 mins max. Not sure if it is any harder to do a Beta ??

[barrybaines]

Now you say that I think I used a couple of G-Clamps in the end

[02-apr]

Thanks Barry. It's obviously one of these things where tolerances vary between individual bikes. I couldn't get the barrel off the studs to twist it. If I ever have to remove it again I'll try shortening the studs by the visible single thread which might just make the difference.