Work has begun on the newest member of the hoard, #19, an '86 VFR700. Back in the day there were both "49-state" models and California-spec bikes. The difference is in the plumbing—emissions plumbing, that is. These were part of the first wave of "EPA" bikes in the U.S.
The various bits of hardware, shown at left, accomplished two things (as far as I can tell). The charcoal canister cleaned up some of the carburetor venting and the air pump injected air near the exhaust port of cylinders #2 & 4.
The idea was that the fresh air will give any unburned exhaust gas a chance to burn itself up after leaving the engine, thus producing cleaner exhaust at the tail pipe. On the next generation of VFRs, these injection ports were added to cylinders #1 & 3 as well. The whole contraption was obviously effective enough to satisfy the feds back in the day, but 35 years later it all produces a lot of potential leaks and no way to test whether it actually still functions as intended. So, I vote to eliminate the system as a whole.
The various bits of hardware, shown at left, accomplished two things (as far as I can tell). The charcoal canister cleaned up some of the carburetor venting and the air pump injected air near the exhaust port of cylinders #2 & 4.
The idea was that the fresh air will give any unburned exhaust gas a chance to burn itself up after leaving the engine, thus producing cleaner exhaust at the tail pipe. On the next generation of VFRs, these injection ports were added to cylinders #1 & 3 as well. The whole contraption was obviously effective enough to satisfy the feds back in the day, but 35 years later it all produces a lot of potential leaks and no way to test whether it actually still functions as intended. So, I vote to eliminate the system as a whole.
The fix is pretty simple. Remove all the hardware, plug the carb ports (five total) and plug the air injection port at #2 and 4. My cheap & simple fix for the injection port is to cut the port fitting off of its long metal tube, tap a course 3/8" thread into the (former) air passage, fit a shortened bolt coated with gasket cement or JB Weld, give it a coat of black engine paint and bolt it back up to the engine block. "Job done," as Edd China used to say.
To my knowledge this emissions system is the only difference between the two versions.
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