Serious MT500 Surgery

[ZIP TIE]

Hmmm Mr Kay! or should I say until recently "Mr Real Men Don't need an electric start"
( unless my eyes deceive me)

[ellrider]

Hmmm Mr Kay! or should I say until recently "Mr Real Men Don't need an electric start"
( unless my eyes deceive me)

Gotta move with the times.

[Mr Kay]

Hmmm Mr Kay! or should I say until recently "Mr Real Men Don't need an electric start"
( unless my eyes deceive me)

Shhhhhhhhhhhhhhhhh, people will talk!

Anyway, real men may not need electric start but it doesn't mean they don't want it

[Franc]

Whisper it quietly, I have been told that the XR front forks are Paoli, not 100% sure if this is true, but the chap who told me is quite clued up, and has been dealing with M'bike repairs and MX/enduro racing for longer than I have been alive.
If it is true then it means the XR400 front end is a direct fit bearings and all.

[Mr Kay]

How about a Throbbing Missile Stainless Steel Performance Exhaust System?







Those headers have a 35mm ID, 10mm more than standard

All the construction details are in the blog, here

[Mr Kay]

Very nice Alex.
I don't want to brag, but the Gazelle exhaust on my 640 is 37mm I.D.

Really? on the headers? Wow. These headers are not far off the size of the standard midsection!

[Minter]

Very nice Alex.
I don't want to brag, but the Gazelle exhaust on my 640 is 37mm I.D.

Really? on the headers? Wow. These headers are not far off the size of the standard midsection!

Nice pipes Alex! be interesting to see how it runs. I was taught that big isnt always best! Larger headers allow the gasses to cool hence slowing the flow down. Hot gasses in a smaller diameter pipe flow quicker.... The dyno will tell all no doubt!

Good progress being made though mate hope we can both have them ready for Spain..

[Mr Kay]

Very nice Alex.
I don't want to brag, but the Gazelle exhaust on my 640 is 37mm I.D.

Really? on the headers? Wow. These headers are not far off the size of the standard midsection!

Nice pipes Alex! be interesting to see how it runs. I was taught that big isnt always best! Larger headers allow the gasses to cool hence slowing the flow down. Hot gasses in a smaller diameter pipe flow quicker.... The dyno will tell all no doubt!

Good progress being made though mate hope we can both have them ready for Spain..

We shall see! It was either Peter Knight or Malcolm from Sportax that said the headers are the main area of restriction that needs addressing. Whilst It's vital that I keep that nice bottom end driveability, I'm hoping to control that with carb setup and cam choice. My main thoughts were that should a 604 crop up in the future, I've already got a suitable pipe. I don't want to be making this all again!

Do we know why hot gasses flow quicker? Is it a relative viscosity thing? Cooler gases are denser so would have thought that more would fit in (and therefore through) a pipe of a given diameter. Fluid dynamics clearly aren't my strong point!

[ZIP TIE]

It's like the venuri on a carb, same amount through a smaller hole so it has to go faster

[ZIP TIE]

The thing with exhaust systems is that like carbs and camshafts there isn't one perfect system that will do everything, you can only get the best compromise for you, unless of course you have enough space under your tank (and enough folding in your wallet) for variable valve timing, programable fuel injection and a valved exhaust system.