Danny, is he sure about 2.2 thou..... sounds a bit tight to me....

I know we all like a nice tight fit..... but ummmm

GeoffD wrote:I know we all like a nice tight fit..... but ummmm

I like a tight fit, always checking to see if the Bournville Boulevard is open & ready for traffic.

Mezo.

the barrel bored out and ready for that new piston


1mm over size

got some motivation and removed the side cover to inspect the clutch, all nice and clean in here!
clutch is in good nick too





as i was having a look around i think i found my bottom end knock



as you can see the primary drive gear nut is loose and there is a lot of play

so i took off the nut and found alot of play in the key



can't get the primary drive gear off without removing the clutch basket so i had to knock up a tool for holding the clutch still so i could undo the nut



pretty sure this was the cause of my bottom end knock, the sound was coming from the clutch side



close up of the key



and the key way


looks like there's some wear in the key way, the left side isn't straight
not happy

Hi Danny,
I think it is no drama.
The key is the soft part in this relationship. The crank will be fine. Get a new key and everything will be fine.
The key just gives the position of the gear. If the nut is tightened properly it will take the load.
Just my opinion... maybe rubish...
Fred

Fred333 wrote:Hi Danny,
I think it is no drama.
The key is the soft part in this relationship. The crank will be fine. Get a new key and everything will be fine.
The key just gives the position of the gear. If the nut is tightened properly it will take the load.
Just my opinion... maybe rubish...
Fred

Yes Dan I don't think it is a problem, if the new key is a bit loose, buy some oversize keystock and file it to suit.

Dirtybrit wrote: Yes Dan I don't think it is a problem, if the new key is a bit loose, buy some oversize keystock and file it to suit.

that sounds like a plan, that should also take up the small amount of wear in the drive gear, bearing cover washer and balancer drive gear, now i'm in 2 minds about the engine build, do i go the whole hog and split the cases new big end ect or do i just do a top end build???

i measured the conrod to crankshaft side clearance 0.50 the book says between 0.25 and 0.75
now how do you measure the small end??????? book says 0.8 and free play limit 0.031

Danjet600 wrote:now i'm in 2 minds about the engine build, do i go the whole hog and split the cases new big end ect or do i just do a top end build???

Split it mate.

Mez.

MEZO wrote:

Danjet600 wrote:now i'm in 2 minds about the engine build, do i go the whole hog and split the cases new big end ect or do i just do a top end build???

Split it mate.

Mez.

There is a bit of work in splitting the cases. In the end it might be better to split the cases. If only to have a look inside at the gears and it is the only time you can clean out the oil pan.

went down the road and bought 2 x 300mm lengths of keystock, got 7mm and 5/16" cost a whole $13
a quick trial fit of the 7mm looks good