Scooterotica

Just had a go at measuring my port timings for the first time. Stage 2 Road/Race tuned TS1 will be using a Franspeed Race.

Here's what I got:

Exhaust 172
Transfer 130

This is with a 110 x 60 crank with 3mm packer.

Would really appreciate any thoughts on if these are ok and I can get on with rebuilding her

Sounds very low on the exhaust to me. I Think standard ts1 exhaust is around 188.

My guess is that you've measured your exhaust upside down or inside out. In other words you've measured how long it's closed rather than open.

degrees disc

hendy wrote:Sounds very low on the exhaust to me. I Think standard ts1 exhaust is around 188.

My guess is that you've measured your exhaust upside down or inside out. In other words you've measured how long it's closed rather than open.

Just measured again and got exactly the same. You say a standard is 188, would mine being tuned not make it different?

Probably would change but would generally increase unless they've added a steel liner. Even with a steel liner 172 would be surprisingly low to me anyway.

hendy wrote:Probably would change but would generally increase unless they've added a steel liner. Even with a steel liner 172 would be surprisingly low to me anyway.

Okey dokey, I'll take it with me tomorrow when I go to local scooter shop for some bits. See if they will have a look, no idea if I'm doing it right

Watched the video again! And re-measured - this time I got 190 - exactly what MB thought it would be

Need to recheck my transfers now

Re-cked my transfers and I was right with them, as you said Hendy, I was measuring the exhaust from the outside, looking through the exhaust manifold

So, timings now, confirmed are:

Exhaust 190
Transfers 130

Which gives me a blowdown of 30

Tried new CNC head and it looks like I will need a head gasket of 2.5mm to get 1.3 clearance.

How do these figures sound???