Depending on where you bought the top end kit from you should be able to exchange it for a different size. You never want to bore the cylinder anymore than needed because once its bored out then you have to buy a new sleeve ( usually around $100 ) and get the new sleeve pressed into your cylinder ( usually around $150). I would strongly suggest trying to exchange the piston/top end kit for the appropriate size, your mechanic/shop should be able to measure your cylinder walls and have a good idea of what size piston you will need after the bore.
A 67 MM piston would require a new sleeve? I thought the sleeves were what was bored?
your existing sleeve can be bored to fit a 67mm piston.
he was saying above, to not go bigger than needed, as the sleeve can only be bored so many times until a new sleeve is needed.
Done at the drop of a hat.
Before you make the plug chop run it is important that the float level is correct, the idle is set correctly and there are no air leaks in the system, otherwise the smoke ring may lie about the AFR.
WHEN ALL OF THE ABOVE ARE CORRECT PROCEED WITH THE FOLLOWING.
Warm up motor to operating temp.
Fit new B8ES plug, ride WOT through the gears and hold WOT in 5th or 6th gear for 10 seconds, or as long as you can safely.
Switch off the motor and pull in the clutch, apply brakes to come to a stop quickly.
Take the plug out and replace the old one for the ride home.
Carefully cut the threaded end off the plug to expose the insulator.
There should be a smoke ring of a cardboard or biscuit colour around the insulator.
If it is non existant or a very light colour, you are lean and require a larger main jet.
If it is a lot darker you are rich and may go down a size in main.
I prefer to run a little on the darker side, I may loose a little power but it is worth it for the peace of mind that I won't need a rebuild so soon.l]
Quick question on the plug chopping and this will be a dumb question I think but I'm going to ask it to be safe... Is it safe to do the plug chopping before the break in period is complete on the new topend or should I give it some easy ride time prior to the chop?
Thanks again for everyone's help and a huge thanks to everyone for not criticizing my lack of experience. I:II:II:I
I read this thread again and I was wondering what all mods are done to the Quad, and what all do you plan on doing to it when you get your Jug back? You said you plan on buying an exhaust, any ideas on what Brand?
When your ordering your top end gaskets, Its recommended by most to only use OEM Yamaha or Cometic base gaskets. The green paper ones should be avoided.
The lack of experience thing, there is no shame in that. We've all been there!
Hope your son is ok. I'm not familiar with the wiseco gasket sets. Maybe take a picture of them and put them up and we will let you know.
View attachment 8181
It looks like paper gaskets, so I should order new gaskets from cometic I'm guessing?
Here is to hoping that the build goes smooth and lasts awhile.