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jakiesdad
08-22-2009, 07:45 PM
Is it normal to go through exhaust coupler gaskets when doing 30-45 minute xc races? I don't know if it is burning away or getting damaged and falling off.

Ryko racing
08-25-2009, 02:56 PM
Do you mean the gaskets at the exhaust manifold or the o rings.

We seal everything with silicone each week and keep the springs tight.

if you mean the pipe to silencer seal you need to trim about 1/2 inch off of the pipe so that the silencer is loose and moves front to back then use the rubber seal. ( make sure that you smooth out the pipe after you cut it with a file or it will tear the rubber when it gets hot.

jakiesdad
08-25-2009, 07:57 PM
Yeah its the pipe to silencer rubber seal. I am thinking that some how it is getting cut and lost.

So what U are saying is to trim a half inch of the flanged part on the pipe, make sure it moves freely and is smooth?

Full Throttle00
08-25-2009, 11:47 PM
Yep, works like a charm. I bought extra ones, then cut the pipe.
Haven't lost one since and still have extras in my tool box.

Thanks Ryko for the front pipe silicone trick. I'll have to try that. It was recomended to buy a doughnut gasket for a KX65 to tigten up the header pipe to exaust port.

Ryko racing
08-26-2009, 07:30 AM
actually if you can get a piece of thicker hose and do the same thing you will never buy one again.

These Cobras are very reliable once you figure out the small quirks.

Too bad my son is outgrowing them as he loves them.

We may have 2 national ready ones to sell . if you know of anyone interested PM me.

Full Throttle00
08-26-2009, 08:54 AM
Thicker hose? Please explain...
Do you have pics?

Ryko racing
08-26-2009, 09:14 AM
use a thicker quality piece of rubber instead of the thin ones. i usually burn through the cobra rubber seal every 3 races. if you can get a heater hose type to fit the pipe it will last longer.

Full Throttle00
08-26-2009, 09:36 PM
I thought of that but would think that the heat from the pipe / silencer would melt radiator hose. I will try it next time we blow through one. But knock on wood, this one has lasted 5-6 races and practice over the last 2-3 months.
If you have any more sneaky tricks & querks for the Cobra, PM or call me.
Thanks

Oh & by the way, I experimented with a rubber fernco coupling, not a good idea...

jakiesdad
08-26-2009, 09:56 PM
Hey!!! Why pass that valuable info in private? Throw it out there for all of us to benefit from.

Adam, U guys gonna be at TPQ on Sunday. Jake is tied with Calvin for first so winner takes all! I have been trying to pump Jake up all week for the challenge.
Also looks like we might have sold the DRR and might have some money to either big bore his burned up 60 cylinder or pick up that 60 U have for a great price.

jakiesdad
08-26-2009, 10:07 PM
So what do U all think would be better and easier on the wallet.

Have our burned out 60 cylinder bored out to 65 and then a new 65 piston and gaskets and then also a new carb to match -or- buy a used 60 cylinder and a new 60 piston and gaskets and use the current carb that was working good on our 60?

The burned up cylinder was because we lost the waterpump seal and bearings and toasted the piston. -also- we are going into indoor season so kinda thinking the advantage of the 60 might not be so noticeable on tight tracks.

Hopefully my ramblings make sense.