Motorcycle Repair: 1973 Honda 175 plug fouling, alfa spider, advancer

Question
Bill -
This is my first foray into vintage Hondas. I am in Italian car guy!

To the question - I just purchased a 1973 175 Scrambler in great shape. However, after 2 or 3 days of driving the bike will start but will not have power enough to pull itself in 1st gear. Pulling the plugs confirms fuel fouling. It appears that, though it runs well for a time, it is running rich. I do not know the storage history of the bike. Should I pull the carbs and clean them? Is there an adjustment I can try? The mechanical injection on my 1978 Alfa Spider is less daunting than this!

Thanks in advance,
Ben  

Answer
Ben, just think of it as a couple of OHC single cylinder engines ganged together.... they are REALLY pretty easy to work on....
FIRST... clean the points, adjust the gap to .0012-014", then move the point plate around until the points open when the F mark lines up with the mark on the stator on the end of the crankshaft. Before you tackle the point setting, pull the whole plate off and check the mechanical spark advancer for sticking, etc...

Once you have the points gapped and timing set, then you can turn your attention to the carbs. There is just a small idle jet, a main jet, float/float valve in the bowls. Unsnap the bowl clip and drop the bowl down for inspection. Float level setting is 21mm, measured from the bowl gasket to the float, just as the float tang closes the float valve, but not compression the spring loaded tip.

TIP: The carb tops unscrew and the slides will pull out (after you remove the seat and tank). The slides are LEFT and RIGHT sided! Often people will pull the tops off, forget which one goes where and reverse the pair. There is a cutaway on the slide that is supposed to go to the REAR (air filter side) of the carbs. This allows a transition of mixture circuits when the throttle is opened. If you look at the carb inlets, with air cleaners removed, you should see the cutaway bevel looking back at you. If it looks like a closed off throat, then the slides are in backwards. Swap sides and the bike should run fine again.
BE SURE that the battery is fully charged.... and the spark plugs are D8HA NGKs.

They are kind of like this http://www.dansmc.com/carbs/Japanese_Carbs/Keihin_Hon_cb72_77.htm  only smaller....

Bill Silver