Paul's Yamaha 3MA track bike

[Louis]

Very good looking Paul.

Just a small question?
Is that your workshop? My house fits in there (twice )

[Paul]

Very good looking Paul.

Just a small question?
Is that your workshop? My house fits in there (twice )

Cheers lads
No louis. Unfortunately it's not. I've rented a portion of a large workshop.
The crap you see in there is not mine either. 

[Toop]

Nice sound and colors, great job Paul !

[Paul]

Cheers toop
I warmed her up today and gave her a good rev
Right pipe is smoking like a bastard! I can't ride it yet as the weather sucks.

http://youtu.be/bPwPK3jpxV8

[casal-fan]

That sounds beautifully Paul.
Bet you´r glad nobody grabbed it while you were thinking of letting her go.

[Paul]

hi boys
finally started work on the SP heads which i want to machine inserts for.
the plan is flat pistons and put the bike back onto unleaded
max HP of course, with a tiny back-off of timing like i did to my 3DP (after a few beers it was decided the 4XV be renamed 3DP, for those that followed that project)
this bike will end up back on the road once the motor is finished 100%, i might move it to france
i also have the "hesitation" that edd has described (coker mods), like him i exhausted all efforts to get rid of it and I feel it's in the heads and fuel, anyhow it cant be rocket science, i will go top to bottom
the 4TW heads worked so well on the 3DP with high grade pump fuel and has proven to be very reliable to (i was worried about the compression being so high some might recall)

[Paul]

With my 3DP getting its annual strip down I'll get a tool made to copy the profile of the heads I use in it for the 3ma. 4TW unleaded heads.
Should have the blanks made up next week or week after.

[maccas]

Paul, are you going to skim 2mm or so off the base of the barrels to run 4DP pistons?

Dan

[Paul]

Paul, are you going to skim 2mm or so off the base of the barrels to run 4DP pistons?

Dan

Hi dan. That's interesting. Never even considered that! Good idea.
Id have to check. Has anyone done it that you know?
What about small end bearing? I think the pin is the same diameter off the top of my head.

[maccas]

I've definitely seen it done somewhere on the forum in the past Paul. I'm going to try and go down the longer rod option rather than skimming the base of the cylinders, haven't got the engine to bits yet though so I'm a way off that!

Dan

[Paul]

Thanks to dan x2
His suggestion and the gaskets. Cheers mate.

I fitted a TZ piston, small end and gudgeon pin. A 0.5mm paper gasket and got it to TDC and measured what I have to take off the bottom to have a zero piston protrusion. It's 1.3mm.

So that's all good.

[Paul]

Some progress
Almost there. Taking it slow and checking absolutely everything every step of the way
We have nice flow over the top.
Only issue is spark plug hole length, looks too long. But we can recess if need be.

[casal-fan]

Thanks to dan x2
His suggestion and the gaskets. Cheers mate.

I fitted a TZ piston, small end and gudgeon pin. A 0.5mm paper gasket and got it to TDC and measured what I have to take off the bottom to have a zero piston protrusion. It's 1.3mm.

So that's all good.

Looking good Paul
Interesting setup!

[Paul]

Some progress
Heads look fantastic. We need to recess the spark plug and machine the base of the cylinder. It'll be back together by Wednesday and the following week I hope to dyno it if poss.

[Paul]

TZ 4dp pistons.
Waiting for new bolts for heads and I'll fire it up.
Already loaded map from my 3xv adapted for 3ma