Topic: Test Ride #1

[Dumbgumby]

Its been awhile since my last post and I've been busy wrenching on the bike in the meantime. For those of you unfamiliar with my bike, I bought it a few weeks ago from someone whom it was given to. The person who gave the bike away had the bike sitting outside under a tarp up here in minnesota for about 3 years. I was told he started it every 'once in awhile'. The person whom I bought it from was running it with brown rusty gas when I bought it. Since then I had cleaned the carbs a couple of times, and tried extensively to clean the tank, after finally being satisfied with milkstone cleaner. I put it all together and it seemed to run good. I felt the head piped and it seemed that #2 was running a bit colder than the rest. I decided to take it down my street to see how she rode. She seemed to be running 300% better than when I bought it. I couldn't resist taking the bike out onto the service road to open her up. As I ran through the gears it seemed to running ok cept shifting seemed a little weird. I looked down at the speedo and realized that I was going 100mph. That freaked me out a little bit cause I didn't have a helmet and I was kinda mad at myself for being foolish. Now I've mentioned everything that I've done to the bike and I was wondering if anyone had any suggestions to do to the bike before actually deeming it 'streetable'. I know enough that I probably shouldn't ride it until more things are looked over. Again sorry for the length, and any help is greatly appreciated.
Thanks
-Calvin

[scondon]

  Good deal. Congratulations on getting those pesky carbs together and running. Did you ever find the pilot mixture screw that was missing?

   If you're doing 100mph down the service road then I would say the bike is "streetable"   Since the bike has been sitting for several years I'd think to check that tires are properly inflated and in good condition. Drain the old oil and put in fresh. Give it a proper tune up(gap valves,set timing,synch carbs,etc..). New spark plugs are always nice.

   3-5 year maintenance would have you change out the fork oil and brake fluid, but a lot people don't. Take the caps off of your master cylinders(brake fluid reservoirs-front and rear) and make sure the fluid in there hasn't gone "milky" and thick.

    The #2 pipe that isn't heating up as much should be checked in to. Bike will run that much better with all the cylinders firing/burning equally.

[Dumbgumby]

yeah.. that pilot screw. I think im gonna go to the honda dealer tomorrow and pick one up. But yeah that test run was with no pilot screws because I thought it would be better if all carbs were the same? Do you think a bench sync would be sufficient? Also I have a sneaking suspicion that my ignition is weak because I don't think I'm getting as good a spark as I should. Oh and the ride was with no airbox on the carbs.. The airbox that I got with the bike only consisted of the upper half with a duct taped on air filter. So I am wondering if I should just do the velocity stacks, or pods with a jet kit. But I am skeptical because I have heard negative things especaially from the purists. Also can I get a jet kit from the honda dealership or do I have to go aftermarket?
Thanks again
-Calvin

[scondon]

   A bench synch should be sufficient, just make sure all slides are as even as possible.

   I'd start with an airbox. Easier to get the bike running as it should and you'll probably have smoother acceleration through the entire rpm range. Ebay has airboxes, you'll need one specifically for the 77-78 750 F or K models.

   I have no idea what happens when you run without the mixture screws. I'm guessing that you'd be very rich at idle. I guess that running without an airbox would compensate for this somewhat. Plan to install the mixture screws and "air filter of your choice" at the same time.

  Why do you suspect your ignition is weak?

[Dumbgumby]

So since my bike is a 72 frame with the K8 motor I should still get the 77-78 airbox? Also I was kind of thinking of maybe keeping the top half and finding a better way to mount a K&N in there. I think that would at least be better than pods and may not have that great of downfall. I think my ignition is weak because I don't get the 'big' blue spark that I guess I should be getting, also it's kind of hard to start when cold. Also when starting I can get it to fire when I hold the starter and start to finesse the throttle while until it starters to really fire. Also when doing my plugs all the wires came out of the boots so I cut them down a little bit with a cigar cutter and screwed em back in. That seemed to work ok, but this makes me think that maybe all the wiring on the bike is like this.
-Calvin

[scondon]

  I don't think you'll be able to get a good diagnosis on starting/running issues until you get the mixture screws and air filter in place. If you're using the same battery that was in the bike as it sat over the years then you'll probably benefit from a new one, or at the least put yours on a charger. Should help with the spark.

   The rubber "trumpets" that connect the airbox to the carbs are a larger size for the 77-78 carbs. I don't know what type of top half you have but if it fits then maybe you can find a bottom that matches. If you've got a digital camera then post a pic of your set-up. Should help in finding the right answers for a "mix and match" bike.

[TwoTired]

   I have no idea what happens when you run without the mixture screws. I'm guessing that you'd be very rich at idle.

Not to be argumentative, but with the IM screws removed, wouldn't there be a clear air channel where the screw was, making the idle mix lean?  I would think it would act as a bypass for the whole slow system in the carbs.

I do agree that complaining about performance issues with parts clearly missing from the carbs is, well.... silly. 

[scondon]

   I have no idea what happens when you run without the mixture screws. I'm guessing that you'd be very rich at idle.

Not to be argumentative, but with the IM screws removed, wouldn't there be a clear air channel where the screw was, making the idle mix lean?  I would think it would act as a bypass for the whole slow system in the carbs.

I do agree that complaining about performance issues with parts clearly missing from the carbs is, well.... silly. 

  By all means, chime in TT. I've really got no clue and am just guessing. Definitely a clear channel, and you're probably right that instead of allowing more fuel it would allow just air.