mancchair wrote:
I can't see the point in cleaning the carb again when this has already been done and the problem still exists, that is without solving the most likely cause of dirt in the carb ie dirty water in the fuel
Also the tuning of a kehein fcr carburettor is s very complex procedure, not for someone new to spannering a ktm
I think we need to ask ourselves how do we know the carb has been cleaned, original post doesn't confirm?
And if it was the garage who did do it, how did they do it and to what end result quality?
Seems odd to me that on collecting the bike from the garage you had to adjust the idle screw to get the bike to fire - what did the garage have to say about the fact you had to do that? Seems odd.
Bike was running when it when in.....and I assume it was ridden home and so ran immediately after the service once you'd adjusted the idle screw. And appears worse after sitting for a month and a week after?
Can't personally see how valve clearances would have closed up whilst the bike has been sitting for a month and a half.
Bike sitting idle, with fuel in it, points to carb and fuel first off to me.
Then the HT firing circuit including plug.
However, it could of course be the main bearings.....
One of the best pieces of advice is to know your own limitations on bike maintenance - there will be folks around in the TRF local section who will know what they are about and will likely be willing to share their knowledge and experience. If the bloke who shows you strips a carb on the trail and pust the parts down in the mud - maybe find someone else.
If you really are not sure what you are doing - then don't. Get someone who knows to watch you do it and teach you - then you'll know. Overtightening a spark plug can be serious, undertightening a spark plug ditto - missing off a plug washer can cause problems, mis-fitting a plug cap can cause bike not to run, taking things apart and putting them back together in a different order a challenge. It's all logical and can be easily learnt - if you want to - join the TRF and its one of the benefits you'd likely pick up. It is a very satisfying feeling to resurrect a dead bike out on the trail and enable it to be ridden home. Amazing what a few cable ties can do....
Carbs are wonderful scientific instruments and the slightest spec of dirt can cause a problem - and a spec of rust can be worse as it likely wont break down - and can ebb and flow with the fuel level change giving intermittent faults - carbs should be kept spotlessley clean inside in my view. Poking at them with sharp instruments can damage mating surfaces, a scratched pilot screw can upset the idle so certainly don't go about it with a knife, scraper, or anything sharp and pointed.
Best of luck - keep us posted.
Cheers
StuartM