Scooterotica

Was giving a mate of mine a bit of help putting a TS1 230 engine into his LI 150 today, we thought we had it to the point where we could start the engine up ( his old engine from a GP 200 that he'd sold but kept the engine) its done less than 2000 miles. when we had a closer look at the front cone, one welded section before the mid section, I noticed it had cracked on the weld and the crack is more than half way around the exhaust, It needs re-welding.

The question is how long do these exhausts usually last... MB devtour's.... or any of the Stainless steel Expansion chambers now available.... this one is 8 months old and has done about 3 months on the road, and no more than 2000 miles....... Is this normal???

I'd talk to Mark first - he'll be better placed to give advice than any of us..............

This is not ment as a dig at Mark Broadhurst as he makes some of the best kit for Lambrettas to date and the exhaust in question makes good usable power... I was just wandered how long you would normally get out of a stainless steel exhaust...... and if you've had one and gave some feedback I would have a better Idea.. The exhaust can be fixed but the scoot is to be used for the Euros and I was wandering weather to pick a non stainless.. As my Taffy has done around 15000 miles and is mild steel and as yet is still in one piece......

One of my mates in Trojan sc had one go at the weld on last years euro, i think they did have some issues with the stainless ones , not sure if rectified as yet , don't scorpian make them?

Scorpion make these

I'm not sure stainless has much to do with it - welds are a weak spot and these things vibrate like hell. I've had many different makes of exhaust crack on me. Though since I've started having all my exhausts ceramic coated I've never once had an issue - maybe the rapid heating and cooling weaken the weld over time?

Then again I'm no metalurgist

Stainless is more prone to cracking as its more brittle (if thats the right word). Its not as flexible as normal steel.

I'm aware of that - just pointing out that other makes crack as well. Can't chalk it all up to stainless can ya?

Ive had a devtour for two years after about 8 months the main bracket cracked sent it back under gaurantee to MB who sent it to scorpion to be re-worked.One other problem i had was with the End Can,the rivets come loose allowing the baffles to move also had replaced under guarantee. Fitted another same thing happened,i now have a Taffspeed End Can on the Devtour (with out rivets) no problems now

Boo wrote:Ive had a devtour for two years after about 8 months the main bracket cracked sent it back under gaurantee to MB who sent it to scorpion to be re-worked.One other problem i had was with the End Can,the rivets come loose allowing the baffles to move also had replaced under guarantee. Fitted another same thing happened,i now have a Taffspeed End Can on the Devtour (with out rivets) no problems now

I had scorpion re-work my stainless end can just to be on the safe side, but later fancied something a bit more trick and fitted a JL kevlar one (JL3 or JL4 ), I figured it was less weight so less stress on the pipe. Other than that, no problems.

The main reason for exhausts to crack be it mild or stainless can be put down to the fitting. Most after market expansions are supplied with some sort of rubber mounting system. What tends to happen is people crank up the nuts as tight as they can and in the process removing the dampening effect of the rubbers, hence a cracked exhaust. Stainless is more prone to this but mild steel will happily crack as well.The other thing that will cause problems is if the exhaust is tight in the jig when its put together then there will be stress on the exhaust when it is fitted, normally sideways and again this can cause the exhaust to crack.