Guys

After 2 years having the MC21 i have finally decided to solve my curiosity and pain in the butt of kicking the bike to start 110 times. and idle problems i had

Please can you see the photos of the top cylinder piston and tell me that this was the reason of my problems?

http://s306.photobucket.com/albums/nn269/demetris74/?action=view&current=HPIM2427.jpg
http://s306.photobucket.com/albums/nn269/demetris74/?action=view&current=HPIM2428.jpg
http://s306.photobucket.com/albums/nn269/demetris74/?action=view&current=HPIM2426.jpg

What does the cylinder look like ?

It could be small pieces of crome from the cylinder wall, or if you run without airfilters, you could have had some sand in the cylinder
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Poul
"If Life Gets Boring, Risk It!"
MC21SE, KISS box
MC21SP, HRC box, racing loom

I would recommend you install your circlip so the opening of the criclip is opposite of the indent in the piston where the small end pin goes (and you use that indent to pry the circlip out).

Just makes things that much safer for the circlip not to find it's way lose and coming out...


Besides that, you had some kind of debree in the cylinder that made it above the piston. How are the cylinder walls? What about the head?

check your big end and small end bearing, make sure the big end doesn't have any play outside spec. Check your reed valves to make sure they haven't come apart from wear and tear. What about the spark plug? Does it still have it's parts all there?

if everything else looks good, I would replace the piston/rings and be good to go.
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Charles Gallant

cgallant

The cylinder walls and head are in good condition no signs on the walls. As well as spark plug, checked the bearings look fine no play. no any foreign materials inside, note that the bike was running but difficult to start and hold idle. so i believe all it needs is a piston rings.

What about the blackness under the piston rings? is that an indication of blow by from the chamber? meaning was loss of compression?

You have also mention that i should replace the piston as well do you think i should?

thanks

Is it good idea to replace the piston as well since i came up to here?

A friend mechanic suggested this

I ALWAYS change pistons when changing rings. Honestly, Pistons are cheap in the big picture, so replace them. Also replace the piston pin, the small end bearing and the circlips. I would never recommend re-using any of those items.

As for the rings, are they all there? Any missing chunks?

I end up with coloring on the piston skirt below the rings. The coloring I wouldn't worry about. I would focus on what looks like nicks in the piston crown/above rings. That means there was some foriegn debree up there bouncing around. THat is unless I am not seeing the pics properly and there are no nicks?
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Charles Gallant

All of the above Charles has said is true, but the state of your piston will not account for it being hard to start. Dodgy battery, coils or plugs are more likely and there is a bit of a knack to kicking one up.

The technique is hard to describe you really need to have a good feel for where the piston is in the stroke as the kick only moves it about 1/2 a cycle and some bikes are just hard to get gong. Andy's has been for a long time for example but mine are both fine and go with your hand on the kickstart first push. Yet as a search will confirm I'm hardly Mr New.Parts (2nd hand bits, rings and clips included on both my race and road bikes, not recommended by any means but needs must and all that).
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Please do not PM me technical questions, if you can't find it on the Forum start a thread

thanks a lot guys

Already order them , Oh and my Japanese friend told me to stock some pistons and rings as HONDA will stop producing them soon due to environmental laws and sh*t...



can you imagine fighting for a piece of piston and a gasket?, and will be wars and killing and misery in the world........

What will we do with out any parts my god is it the end of the world?