450 -> 570 start issues

[nks0]

I have an issue with a 2010 Husaberg FE I was wondering if you may able to offer some advice

 - I have a 450FE which was taken to the KTM shop here in town and they changed the bore over to a 570, (still has 450 cam)

 Ever since they did that its been a bitch to start. Sometimes it will fire easy but most the time it will wind over but not with enough momentum to start.  It will start when I jump start it but it does still take a bit. It does have a new ssb 195cca battery in it too. 

 - i have tried to research this and have come across some people saying there were issues with the cam with the auto decomp, have you come across this? and is this likely to be the problem for starting, if so can i address it without getting a new cam. someone said to shim the ex valves tighter to allow the valve to open more. but i wouldn't do that unless a heard from a more reliable source. at the moment it has a new piston and i have re shimed the valves to spot on in the middle of spec range. 

- the other interesting thing is, if the choke is on or the throttle is slightly open or full open, the bike will hardly turn over at unless with jumper and even then it struggles and not a chance of starting which i find strange... 

any help would be greatly appreciated.. 

[Escalator]

Storke on 450 is 63.5mm and on the 570 it's 70mm could be your major problem. 

[Atolduso]

Are you running higher compression? I needed a higher cranking amp lithium battery when I bored my bike.

[nks0]

1. nah same stock compression and has a higher cca amp battery

[Atolduso]

11 hours ago, nks0 said:

1. nah same stock compression and has a higher cca amp battery

Did you ever figure it out? This post was a long time ago lol

[nks0]

nah no solution yet. i started the bike the other day about 6 times and it started every time.

hopefully will take it out for a ride and see what the g - o is... but i've been thoroughly through that bike exchanging parts and so forth, and if there is a problem its beyond me. 

[highmarker]

A little late but shop that did my buds ktm 570 suggested the 570 cam for easier starting/cranking

 

Edited January 5, 2018 by highmarker

[HusaBeast]

Would check the TPS setting bc initial voltage governs fuel volume at start. It’s so sensitive and shop may have bumped it lean when working at cylinder. Or worse, moved it without resetting it which made my FE 450 not start after injector cleaning.

[chris nelson]

I wish I could help you I think though your piston is for a 570 I wonder what you deck height is? with the 450 crank. if that is ok? I think the only thing you can do is put in a 570 cam shaft.