Reply To: 3-4k stutter

Forums Technical Two Stroke: Help needed 3-4k stutter Reply To: 3-4k stutter

Matthew Nichols

Hi guys,

Have changed coil for a known working one- no difference.

The bike in general does feel much peppier but only since cleaning out the carb thoroughly. It does feel a lot better, but don’t get me wrong, the bike only does the ‘stutter’ when the throttle is at a steady position and the rpm is going up on the engine in a gradual and civilised way (until anywhere between 3-4k) when it will require either a gear change, or more throttle to circumvent this. Most prevelent when cold, but it’s a lot better now that I cleared out the carb. If I am actually trying to get somewhere fast, then you don’t really even notice it- and of course- i’m tainted and biased now though – my senses are in tune now to find any fault in that range.

I’ve been looking at the slide, and although there is very little play slide in bore, there is significant scoring, piston side. It’s had these since I know, but of course with an extra 17k on it in my ownership wear will always occur.

I’ll be looking to find a low mileage original slide first, because I hate mucking around with bikes that are working perfectly, – but if I cannot then I will definitely be taking that other carb.

New spark plug cap and HT lead were installed only a few months ago- I can check the resistence in the cap- but normally when caps have resistors with high resistence it mainly causes a lumpy idle- but it’s a perfectly valid thought. I’ll check it.

I use Denso W22FSU sparkies, and i’ve already tried a handful, including of different makes; champion, ngk, beru- but no effect.