Hi,
John and Mikey here. Thought I would like to give you a head’s up so you could avoid a problem we had.
Car is 1972 Comet, 250 with a Carter RBS carb. Car was a gift that had been sitting for quite awhile. Mikey’s first car; he didn’t have to take the bus to school. Naturally, we rebuilt the carb as one of the first things. It ran slow but steady then started to run worse. Did the old idiot's part swap out routine.
New parts included fuel pump, Duraspark ignition module, etc. Changed out the coil for Accel aftermarket one no help. Compression showed low on number six, others OK. Plug check showed running rich. Put in another rebuild kit for carb and it ran OK for a while then the driveability and gas mileage started to go down. His mom and grandma decided he needed a new more reliable (read safer) car so the Comet got parked.
Last year as a hobby, we decided to fix the Comet. Must be a fuel problem, maybe bad gas or junk in the tank. Replaced the gas tank, was leaking at the top anyway. Found another NOS carb kit on the ‘Net real cheap, closeout. Ran OK for only a couple of blocks and then the old too rich syndrome. In desperation we pulled the head, as much to teach Mikey car fixin’ as anything else. Number six piston had bad rings. Rebuilt the head, valve job, etc. Put it back together and now compression OK on all six. Engine nice and quiet, no mechanical noises. Still ran like crap.
Problem was the NOS carb kits. There was a “step up rod diaphragm assembly” in this particular carb that was not compatible with the (People’s republik of) Kalifornia oxygenated gasoline. It dissolved and quit working, making the carb very rich. I was able to buy the part from Walker Products and that fixed the problem. This was a new part, formulated for the modern fuels.
Moral of the story: don’t buy old carb kits or other fuel components. They might have rubber parts that dissolve in newer gas. In fact, probably any carb kit you could buy would have been sitting on the shelf for a long time. Also, believe the spark plugs. Funny how we ignored the obvious especially after many years of rejetting motorcycles based on plug readings. Hope this helps someone out there to avoid the problems we had.
John and Mikey
John and Mikey here. Thought I would like to give you a head’s up so you could avoid a problem we had.
Car is 1972 Comet, 250 with a Carter RBS carb. Car was a gift that had been sitting for quite awhile. Mikey’s first car; he didn’t have to take the bus to school. Naturally, we rebuilt the carb as one of the first things. It ran slow but steady then started to run worse. Did the old idiot's part swap out routine.
New parts included fuel pump, Duraspark ignition module, etc. Changed out the coil for Accel aftermarket one no help. Compression showed low on number six, others OK. Plug check showed running rich. Put in another rebuild kit for carb and it ran OK for a while then the driveability and gas mileage started to go down. His mom and grandma decided he needed a new more reliable (read safer) car so the Comet got parked.
Last year as a hobby, we decided to fix the Comet. Must be a fuel problem, maybe bad gas or junk in the tank. Replaced the gas tank, was leaking at the top anyway. Found another NOS carb kit on the ‘Net real cheap, closeout. Ran OK for only a couple of blocks and then the old too rich syndrome. In desperation we pulled the head, as much to teach Mikey car fixin’ as anything else. Number six piston had bad rings. Rebuilt the head, valve job, etc. Put it back together and now compression OK on all six. Engine nice and quiet, no mechanical noises. Still ran like crap.
Problem was the NOS carb kits. There was a “step up rod diaphragm assembly” in this particular carb that was not compatible with the (People’s republik of) Kalifornia oxygenated gasoline. It dissolved and quit working, making the carb very rich. I was able to buy the part from Walker Products and that fixed the problem. This was a new part, formulated for the modern fuels.
Moral of the story: don’t buy old carb kits or other fuel components. They might have rubber parts that dissolve in newer gas. In fact, probably any carb kit you could buy would have been sitting on the shelf for a long time. Also, believe the spark plugs. Funny how we ignored the obvious especially after many years of rejetting motorcycles based on plug readings. Hope this helps someone out there to avoid the problems we had.
John and Mikey