Weird probelm

Not long ago i rebuilt my topend and the bike was riding really good... This weekend i took the bike out and i started noticing a "knock" sound, it usually happens when im engine breaking or slowing down.. Thats when i notice it, im not sure if its there at higher rpms or not because i cant hear it. By the end of the day, my bike was dying very easily... And it sounded like it coughed before it died, and misfired couple times.... WHat possible things could i check?

how old is the gas in the tank? carb nice n clean? did you check to make sure the rod isnt bent or anything?

I just filled it with new gas that day, im gona take the carb out and clean it tomo... But i dont know what the knocking could be??

piston slap??? A warn out 2 stroke. it will be cheaper to fix then a four stroke for sure

Strip the top-end down and check it out.

sounds likes its a worn out top end. But i dont think thats it considering you JUST did it. are you sure you did everything correctly? heres the things i can think of

worn out top end

bad gas

wrong piston and its slapping against the head (too tall)

bad rings

bad bearings (you replaced the needle bearing, right? your always supposed to)

I started taking it apart but wont be able to get cylinder head off today... WIll have to do it tomo, it seems it started to run bad after went through a fairly large puddle. I dont understand why it wuold be more difficult to kickstart it tho?

Strip the top-end down and check it out.

Easy for you to say

did you make sure u got all the water out of the engine? drain the carb?

Easy for you to say

if you know anything about bikes, its not that hard.

Well i prety much think i nkow what the problem is... Took the cylinder head off and the head gasket was leaking... There was traces of coolant around piston and cylinder wall... I cleaned it all out... I remember reading honda has a problem with these steel gaskets, because the gasket is in perfect shape etc... Is there some kind of sealant u can buy to seal the gaskets???

So that takes care of problem #1, one thing i noticed tho.. When you give 1 kick to the kickstart, how many times should the piston move up and down? Mine goes all the way down, and up and down and almost up again... I dont remember if thats how many times it does it, is that normal?

yeah thats normal. as for your leaky gasket, make sure all the dowel pins are sitting in the cylinder flush, sometimes they can come loose, to fix this just put 2 nuts on the dowel pin and tighten to the specified torque. i had this problem and it took me hours to fgure out why the head wasnt sitting right then i finally figured it out. it might not be the problem but its worth checking. hope this helps.

What do you mean they should be flush? Like the flat part at bottom of pin should line up to face of cylinder? All of mine were atleast 1/8" from the cyllinder head mating surface...

when i was rebuilding my top end i noticed that one or 2 of them were supposed to be raised and the rest werent, you can check this out by looking at the underside of the cylinder head and seeing if there is room for that 1/8". what im basically saying, is that the cylinder head should sit flush and tight without the gasket, if it is not, there is your problem. and it wouldnt hurt to re-torque the dowel pins anyway, it could solve your problem.

Easy for you to say

It's not that hard and it'll give you piece of mind. The best way of diagnosing the problem is stripping it down and checking everything out. It's worth the work of taking apart the top end and finding the problem before the piston grenades and you need a new bottom end as well.

I don't see how your response benefits or helps this guy in any way.

I just put it back together, was runnign fine for a bit but then crapped out again.... I checked spark plug for arc but it was giving anything, maybe its electrical problem as well...

haha omg im such an idiot... problem fixed... :ride:

haha omg im such an idiot... problem fixed... :ride:

Had to turn the gas on, huh? :ride:

u gonna tell us what it was? lol

u gonna tell us what it was? lol

Ya, spill it monkey wrench...what did you forget to do?

We've all done really stupid stuff...dont be fraid'

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