300 running issues

[Jon250]

Hi guys
A friend has just brought a 300 57plate, it's got what I believe is a fuelling issues, the problem is 1st & 2nd it won't rev out. 3rd upwards it's about to come on the PV and it splutters horrible once passed it pulls well.
The PV is set ok and not seized. Has anyone suffered from this, and what did you do to solve the issue?
It feels like mid range fuelling,so I think a needle problem.

Thx in advance

Jon

[Moto7man]

This sounds dumb, but have you pulled the air filter and cleaned it? A long time ago I had a buddy who cleaned his filter but left a rag in the airbox, and it had the same issues.

[gassergrant]

hi mate

Plug,, cap could be reeds, blocked carb, crap in the tank
bad earth, coil, cdi
clean the carb and check nothing has come loose ie jets then pull the reeds as some times the corner breaks off.
start with the easy stuff and what's not going to cost as it may be a simple fix
then change the plug even if its a old known working one check and clean the wiring connections and clean the earth, I would put some oil on them like wd40
if nout change the coil and worst get the cdi checked

hope this helps

[Jon250]

Hi
Yep air box is ok. Carb stripped and checked, new plug and cap, earths seem ok but will check with a meter.
Going to a dyno next week to check the fuelling, see what that shows

[Wimpy525]

Check the silencer sounds like a blocked spark arrester. Just had this problem I have the Leo Vince silencer and the spark arrester screen was plugged. My bike ran the same as yours.

[snailspacejase]

I've got the same problem with my 09 300 nambo. Only had it a week so hardly started work on it yet. It will be interesting to see how you get on.
Good luck.

[Boom Boom]

Originally Posted by Wimpy525

Check the silencer sounds like a blocked spark arrester. Just had this problem I have the Leo Vince silencer and the spark arrester screen was plugged. My bike ran the same as yours.

+1, friends 6-day done the same thing.
Removed screen and just fine

[snailspacejase]

Hmmmm. Opened up my exhaust and it was fine, so don't think that is the cause for me. The air filter was less than spotless though. Clean now and ready to try at the weekend.

[bazzagas]

Check your jetting, especially the needle. Remember it's been scorching hot in the UK lately, though it has cooled a bit now. If you are still on the stock N1EF or G needle it will be way rich. If you follow Jakobi's advice on jetting you won't go far wrong and you will get so much more from your bike. It's a quick and easy fix and well worth the effort. I put up with mine for a year and a half before I found this site and realised the standard jetting was all wrong. Less than 10 quid and 10 minutes work had the needle swapped and the bike transformed. I wouldn't waste time and money on dyno time, tuning for off-road is about response and feel from the the motor, not flat out WOT running. Just my tuppence worth.

[snailspacejase]

Right. I've still got the N1EF in mine. DDK sounds good but not sure where to get one. Any recommendations and sources for needles?
Cheers