Thread: Ktm 660 smc twin pipe conversion / power loss

Hi can anyone help? I have currently converted my 660 smc in to a twin pipe back end and it seem to lost power at the top of the rev range. It currently was set up at hm racing with a full akra system, silver tune k&n and jets to suit and kicked out a very respectable 67.7 bhp. However now it's got twin akra's and standard headers it seems flat at around 6000 rpm, do you think it needs rejetting as my friends shitty sv 650 two up was level pegging me tonight and I had a very red face : (

Any info would be great thanks

Originally Posted by Lukektmking

Hi can anyone help? I have currently converted my 660 smc in to a twin pipe back end and it seem to lost power at the top of the rev range. It currently was set up at hm racing with a full akra system, silver tune k&n and jets to suit and kicked out a very respectable 67.7 bhp. However now it's got twin akra's and standard headers it seems flat at around 6000 rpm, do you think it needs rejetting as my friends shitty sv 650 two up was level pegging me tonight and I had a very red face : (

Any info would be great thanks

You have taken a bike that was in an optimised state of tune for the key components you list and fitted a different exhaust system - surely you didn't expect it to run better than the experienced chaps at HM had achieved?

Don't see the point in changing key components if it aint going to make the bike perform better - and your home handyman skills are unlikely to outperform the professionals. Time for a rethink or a rejetting and a dyno run?

The reason I changed the exhaust is because I changed the rear end because the old rear end looks shite nothing to do with trying to out do H M racing as the lads there are great. I was just hoping that it wouldn't make to much difference, I'll have it dynoed and rejetted I think.