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new premiers adjustment

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On setting tick over, the throttle slide screws wind all the way out and yet it still idles - a change to the pilot screw doesn't have much effect as revs are not low enough to make one screw effect the other, as per manual. Have finally swapped carbs but I will now take them off AGAIN and fit new carb intake insulators. The allen head screws (what a faff!?) were close to bottoming out so I wonder if this joint is not sealing but is it right that there is no sealant here? So much time has been spent cleaning the old carbs on the Interpol, and so nearly back on the road after 20?! years of rebuilding it, do I end up taking it to a specialist after all.. Any thoughts appreciated. Mike

Hi Alan. Thanks, I am fairly convinced that the slides are snapped shut. I synced these before carbs went on - and slides not concealed by the rubbers on the mk2a (I fit these to air box first of all to avoid that faff..) But as carbs are coming off again I will repeat the process at the top cap adjuster (starting with fully open, then lifting off together.) Cable run etc are all good. I believe I can feel the point that the slides hit bottom, and not the wound out screw adjuster, through the screw driver but I may be mistaken. Having messed around with settings this is how I sync the slides, with the carbs on and rubbers in place. I will do the new insulators without sealant and shorten the screws and hope to report a success. Mike
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If the slides are shut then they are sitting on the tick over screws, there must be a small (1mm) slack in the throttle cables at this point, then using full throttle you get the 2 slides in sink via the two carb top screws that adjust the throttle cable length, but you have to check that you still retain this slight slack in the cables as the sleds drop onto the tickover screws.  
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If there is a cable splitter in use check it is not being pulled out of line and cables are properly seated into it .cables on both entry and exit need a little slack .if slides are not to "hang up".If engine revs are too high  you can be on the next phase of carb operation and no amount of Idle adjustment will do anything.
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Slack in the cable at the carb tops is the most important part of tuning the carbs, without the slack it will be a pointless evolution. 
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Problem is higher up as well which is why I can usefully start again, by refitting my new carbs and all the points raised give a better understanding at a crucial stage. On checking, the slack wasn't there and so the carbs haven't been fine tuned yet. I can even look forward to getting fresh insulators and having another go. Thanks! I never counted on the work required being essentially to the standard of a new machine!! I found the crank wasn't typical and had no keyway for the rotor which meant starting over, several years ago! Also the old Interpol had 23t sprocket and I'm in 20mph London so last month the primary was off for 3rd time. I am learning the patience of a saint.
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I found the solution to maintain the synchronisation of the carb slides over time was fitting the splitter tight to the frame, in my case to the small diameter  tube below the backbone. 
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With carbs off the old insulators were worn but also wet, so deff not sealing. Face on the manifolds and head badly needed honing flat but an easy job with a diamond sharpening stone. Allen screws were shortened to stop bottoming out threads - maybe from previous honing? Also removed half inch of throttle cable outer to add slack, and using top cap adjusters with a view of the slides full open and opening together was easy to set, plus the slide screws as they engaged. Tickover could now be wound down with these, equally on each side but pilot was hard to gauge and ended up close to 1 and half out anyway. I was sorry to miss ride to NOC at Ardingly today but hopefully it's finished?! Thanks for advice

 


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