I hope collective wisdom and experience can help me sort out a fuelling issue I have with my 2011 2.9.
As received from the previous owner the engine was often 'bogging' quite badly, and on a number of occasions would hunt when engine speed came back to idle. A few fellow riders suggested to'clean it out' by revving the guts out of it for a few secconds before starting a section, and this did seem to help, but in longer sections the bogging would start to re-occur.
So, I checked the carb setting were as per Splatshops' recomendations :- https://www.splatsho...rco-preparation, and it seems that the 2.5mm restrictor in the fuel inlet to the carb was missing and also the float height was at 21mm whereas it should have been 18.5mm with the 250 jet that is fitted.
After taking the bike out again nothing seemed to have changed, so I had a fiddle with the needle height to see if it would make a difference.
Splatshop spec for needle height says middle groove on needle with washer placed nearer to nut. This is what I had as received. I had a go at lifting the needle to see if richening would help, and it made the bogging worse. Dropping the needle seems to be the best improvement I can make, and currently I have the circlip in the top groove with the washer between the circlip and the main slide itself, which seems to be the best I can get it. The fuelling is still not right though and the bike is still sluggish from low engine speed compared to a 2.5 of the same year (although this was Luke Walker's bike and he told me he'd changed the carb from the original to make it run right!). The hunting at idle is no longer happening. Also, with the needle set at any height the engine is fine for medium to high speed running.
Can anybody shed any light on how to improve the fuelling from this current condition? I'm not that familiar with fiddling with carbs and not certain what to try. I 'think' that changing the pilot jet would probably be the next thing to do, and perhaps fitting a smaller one to lean out the low speed running and perhaps lift the needle back up again, but not really sure.
I've spoken with Chris at Splatshop, who has been very helpful, but he's on hol this week and i'd like to get this sorted sooner rather than later....
Any knowledge/thoughts/experience would be greatly appreciated.
Edited by raygrilli, 30 January 2012 - 03:25 PM.