07-06-2014, 12:21 PM
In my quest for economically adding a LITTLE bit more sound, and improving near perfect running, I drilled a 3/4" hole in the rear baffle 10" inside the exhaust outlet. Then trying to address the slight surging around 2000 rpm, most noticeable when slowly revving the engine under no load, but sometimes noticeable under load I added a 1.5K ohm resistor in series with the Gray/Blue wire for the IAT sensor. So far, ONLY SEAT of the PANTS, results are just a bit more exhaust noise on the road( I like not real loud ) and slightly better throttle response. ( more eager / make sense?). The 1.5K ohm resistor should have the greater effect at higher IAT temps and little to none at lower temps. The slight surging under load seems to have gone and when revving the engine slowly not under load is hardly noticeable. Mileage seems unchanged at about 50MPG. IMHO the exhaust is the most restrictive part of the engine. Many small diesel engines , twice the size of the CB, run filters similar in size and design with no noticeable problems, until very dirty, and diesels require a lot more air than gas ( until full throttle ) as they are compression ignition and have no throttle plates.