OzVMX Forum

Clubroom => General Discussion => Topic started by: oldyzman on July 11, 2013, 08:36:48 pm

Title: Warning - not VMX KTM300exce 2008 Rev Limiter
Post by: oldyzman on July 11, 2013, 08:36:48 pm
Hello,
Can some advise if the std ignition system has as rev limiter? If so what effect is felt when it cuts in.
Brett
Title: Re: Warning - not VMX KTM300exce 2008 Rev Limiter
Post by: evo550 on July 11, 2013, 09:04:38 pm
I had a '08 250 and now a 2013 300 and race in moderns and have never come across a rev limiter yet.. I do third gear starts and the throttle is to the stops waiting for the gate to drop and it doesn't miss a beat.
Are you having troubles at high rpm?
Title: Re: Warning - not VMX KTM300exce 2008 Rev Limiter
Post by: IT400C on July 12, 2013, 10:02:01 am
Hello,
Can some advise if the std ignition system has as rev limiter? If so what effect is felt when it cuts in.
Brett

If you've got one of the harder powervalve springs in (yellow or green, but green especially) - it can feel like it's got a rev limiter kicking in I suppose.

I only tried the green spring once (hardest - powervalve stays closed longest), and my 250EXC would only get to what felt like 3/4 revs before it just stopped going any further..

Check which PV spring is in it.  I found I liked the Red spring with the longer standard muffler for general bush riding.  For me it gave the best combination of mid-range grunt and top end power when needed.

Tony
Title: Re: Warning - not VMX KTM300exce 2008 Rev Limiter
Post by: oldyzman on July 12, 2013, 11:45:57 am
at about 3/4 it often does not want to go any higher, I bang it back a gear rev it out then change and its OK. I am using a sx muffler and always have cause i like the snappy hit and better note... comming off a road registered YZ250 2 stroke the 300 was too tame stock..
Brett
Title: Re: Warning - not VMX KTM300exce 2008 Rev Limiter
Post by: GMC on July 12, 2013, 12:00:26 pm
When I had my 300 years back I experimented with the power valve to see what it was achieving and whether it was actually working, I disconnected the push rod and zip tied it open
Result was a peaky engine with minimal bottom end
Then I zip tied it shut which killed the top end and it wouldn’t rev out properly.

It sounds to me like your power valve is stuck shut, I doubt it is a rev limiter problem
Title: Re: Warning - not VMX KTM300exce 2008 Rev Limiter
Post by: oldyzman on July 12, 2013, 12:06:53 pm
Yep maybe the PV is a bit sticky... Good point GMC.
Brett