99stewby Posted April 8, 2014 Report Share Posted April 8, 2014 Could anyone offer any advice on this? 2007 250 has a wandering idle and sometimes bogging and cutting out. I've been trying to get to the bottom of this problem and have done the following. Removed and fully cleaned the carb / jets, Checked the float height (it is parralel with the carb housing itself if that is correct) Changed the filter in the carb. Chnged the air filter with new oiled Jitsie checked plug and is fine, running a little lean if anything and was a new plug 3 hours ago. Changed fuel hose and in-line filter to carb. Checked mixture adjustment to how i know it runs well (3 turns out) to give and adjusted slightly either way with no improvement. sprayed carb cleaner on intake manifolds, spraying on manifold from engine to carb is fine, but when spraying on manifold between carb and air filter the engine rpm drops to the point of almost cutting out and once did cut out. Normally i would say that indicates an air leak but it is so close to the air intake/filter im not sure if its just being sucked in though the filter... I have ordered a new manifold anyway just to be on the safe side... Also when bike is running at an acceptable idle speed when outside the garage as soon as i wheel i inside, still with the engine running, the revs drop so low it cuts out. It was slightly windy outside but temperature difference was minimal. Is this normal??? So there you have it, any one have any clues? Thanks a lot!! Stu Quote Link to comment Share on other sites More sharing options...
cabby Posted April 8, 2014 Report Share Posted April 8, 2014 Air getting in somewhere ? Reed valve ? Quote Link to comment Share on other sites More sharing options...
dadof2 Posted April 8, 2014 Report Share Posted April 8, 2014 Make up a blanking plate for the barrel to replace the exhaust, block the inlet to the reed block (where carb fits) with a bung and hose clip. Either the bung or exhaust blanking plate needs a hole for a tyre valve. Pressurise to between 5 an 7 PSI to see if you have a leak. If it is a dellorto carb check the fine wire clip that holds the float arm to float valve plunger ifs fitted correctly and not distorted. Quote Link to comment Share on other sites More sharing options...
copemech Posted April 9, 2014 Report Share Posted April 9, 2014 I can only guess at likely culprits. First, better folks than you and I have been fooled by not getting hidden grit out of carby passages and jets. Pass a fine soft wire through the low speed jet and flush all pages with carby spray and blow out with air! Not uncommon for these things to need crank seals. You may do some basic tests easily by removing the mag cover and spraying the carby spray just a bit to see if that changes the idle. Another thing would be checking the primary side by testing for vacume /pressure changes on the tranny vent tube below the carb. A clean hose and vacume on the toungue is a good indication. A clear hose and the bike pulling water uphill would be another, so would excessive bubbles! There is no vacume per se on the airbox side of the carb, only ambient air rushing in, so outer boot is out! Quote Link to comment Share on other sites More sharing options...
99stewby Posted April 9, 2014 Author Report Share Posted April 9, 2014 Ok thanks for the replies guys. I'll do the basic checks on the cranks seals. If I have no joy there I think I'll jut get it down to splat shop, hopefully they'll be able to get it sorted!! Quote Link to comment Share on other sites More sharing options...
99stewby Posted April 9, 2014 Author Report Share Posted April 9, 2014 Ok so i checked the vent tube and it had a bit of dirt in there but didn't seem enough to block it, stuck my tongue on the end and couldn't feel any sucking. I loosened the mag cover and warmed the bike up, left it to idle for a min and it stayed pretty constant. As soon as i gave a small spray of carb cleaner inside the cover the revs dropped and bike cut out. I tried this a couple of times and happened everytime. Does this mean 100% the seal is leaking? If so i'll get them both changed at splat shop hopefully next week and see where we go from there. Thanks for your help guys! Quote Link to comment Share on other sites More sharing options...
copemech Posted April 10, 2014 Report Share Posted April 10, 2014 Sounds like you are on it! Splat Chris has the Viton replacements too! Quote Link to comment Share on other sites More sharing options...
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