My bike has 147500 Ks on him, and sometimes I'm a practicing idiot. And yes I've read Pete's story about leavin shit alone... Bike has got a Beetle map and an Agostini 2 into 1 and an Agostini reverse cone muffler standard air box minus the snorkel and standard air filter. With the manometer connected and both air bleeds shut, the vacuum is biased to the left side up to 3000 RPM. From there on the bias favours the right. He has been like this from day one. So ...I hear you cry...open the right butterfly with the linkage screw. Do that and he starts to miss and fuck about, not outrageously so but he stutters. When Pete put the map in my bike he balanced the T/Bs @ 4000 rpm no drama. Fine when accelerating, trailing throttle ,idle alright and winds over a few times on cold start. Stuttery constant throttle. and the odd ping. Left spark plug dark colour and right not quite white. However today after I swapped TPS I adjusted the butterflies according to plug chop colours the stutter on constant throttle has almost gone and both plugs are a light grey, no pinging , or popping , near silent gear changes, feels stronger and sweeter. Trying to solve this has driven me to great lengths. I tried the PCV things and dynos, different mufflers, I even made a few myself ...pissed the airbox off and tried foam filters on mandrel bent inlet pipes. pulled the heads off and cleaned up under the valve seats and blended the inlets to the head etc , stepper by pass, tried different coils, T/Bs , injectors, coils, ECU ,manometers , carbmate. and et fuckin al. All the while he went alright but still had the stutters. Wear in the throttles, link rod ,valves , rockers etc will obviously impact things but the vacuum bias has been constant. The only thing I hadn't tried is more symmetrical headers. The Beetle map has given the best improvement yet
So today Ive been plug choppin and adjusting and the bike goes like the proverbial freight train with just the slightest little stutter. I've yet to try a cold start but I'm pleased.
I will brace myself for your howls of derision and snorts of laughter with a cupla rums and a stubby or 2 and a ride at sunrise tomorrow.
Subject: Why is it so ? 
Mon Jan 19, 2015 2:10 am
