Going into the engine. Questions.

[Soniq7]

Hi guys,

Ive been collecting parts for my 400s hop up.

New wiseco prolite piston w/rings

400e top end gaskets

hotcam intake

box o' valve shims

MCCT

DynoJet kit

I got a good deal on the piston kit. Can I just mic it and install? I thought I heard something odd about installing the circlips?

Do I use assembly lube on the cam or will it kill the clutch?

Will the recommendations in Burneds dynojet FAQ be the best starting point in the jetting process?

Im at 16ft elevation, bike has FMF powerbomb pipe and 3x3 mod. Its currently running 1 jet size up from stock.

I love this bike, it really put the fun back into motorcycling. I hardly ride my streetbikes anymore.

Any help sincerely appreciated,

S7

[Erik Marquez]

Look at the cyl, if the crosshatching looks good .. Install the piston dry and go.

The rings will need fitting. They will be too long for that bore. Good sharp, fine cut file,, and a piece of glass will work for fitting the rings.

You can use a smidgen of engine assembly lube on the cam journals,,, and lobes.. Or you can douse it with oil. I've done both a lot,, no ill effect.. But I always change my oil& filter.. right after a fresh engine start up.... So what ever might have been in the oil,, comes out right away.

Yes, start with the standard DJ jetting for 3x3 and aftermarket pipe and your elevation..

[Soniq7]

Ah! The ring end gap, thanks for reminding me. What is the correct gap size?

S7

[Erik Marquez]

0.50mm for the stock piston.

Weisco has a different standard if I remember right,, and it is stated on the installation instructions that come with the piston.... If I still have mine at home, I'll post later.

[Soniq7]

I had those instructions, until my dogs ate the piston box..

[Stu35]

Look at the cyl, if the crosshatching looks good .. Install the piston dry and go.

The rings will need fitting. They will be too long for that bore. Good sharp, fine cut file,, and a piece of glass will work for fitting the rings.

You can use a smidgen of engine assembly lube on the cam journals,,, and lobes.. Or you can douse it with oil. I've done both a lot,, no ill effect.. But I always change my oil& filter.. right after a fresh engine start up.... So what ever might have been in the oil,, comes out right away.

Yes, start with the standard DJ jetting for 3x3 and aftermarket pipe and your elevation..

Can you elabotate about the ring gap? How do you check this - install on the piston, compress into groove then remove and file needed material out?

Thanks.

[Wayward Son]

you install the ring by it self in the cylinder.use the piston to square it up in the cylinder.you use a feeler guage to check the gap.

[Stu35]

Thanks. Makes sense - otherwise you are stressing the rings too much. This site is great! ?