Recent content by Ketchup

Good question. I don’t think so.

The elevation factor is significant. Great to hear it tightened up. Kickback is often from ignition timing. Did you advance it?

I think this is really interesting. Have you measured compression?

Cabers take 5-10 tanks to break in, but if you’re at 155 you probably won’t hit 170 after break-in.

@MustangMike, what you were saying in the Muffler Mods thread is definitely worth thinking about. I quoted you below for a little context. So there are two things here to discuss: expansion chamber pipe saws and the general principle of exhaust back pressure as applied to can-style mufflers...

This is what I meant by pipe, not an expansion chamber. Not ugly at all.

I saw $80 shipping, 35-45 days delivery. I think if you keep your order below $600 the tariffs aren’t applied.

Is that for throwing or for kindling? Looks nice.

A simple way to think about it is the muffler outlet restricts flow. If you open it larger than another restriction in the saw, you’ve made all the gains you can until you fix that constriction up stream. Ported saws typically reduce restrictions through the whole system, so their rate of...

We might have to take this to a different thread because it’s a legitimate debate: Is back pressure valuable, or is it only helpful if the transfer scavenge loop or chamber compression is fundamentally weak? I see it both ways but I lean toward the second. Back pressure may be relevant, but...

I don’t have particular 661 knowledge here, but generally speaking it matters less how you open up the can, it matters how much. If a bark box has a 1” opening area and or you have 2 side outlets with deflectors that add up to 1” area, you’re going to get similar performance. There are...

Looks really good!

That seems like part of it. Weight savings. The 564 literature says less vibration and slimmer case. That may also mean less case volume which tracks with 500i and fuel injection not needing the same port time area. Funny though, 500i has a long intake duration.

What is the stroke? 500i is short stroke. Interesting. Edit: My memory is going. We already hashed this out a bit in the 564 thread. Does anyone have an official measurement on stroke or bore?

Have you pressure tested it? An air leak would be good news. I would just clean everything enough to not introduce dirt and put it back together. In particular, don’t mess with the injector, or the pressure sensor. Just get the dirt off them. Be careful with the wires on all electrical...