Topic: first ride longer than "around the block", 500k2 lives! some questions

[gmoss]

After a few dozen hours spread over ~3 months (with a shoulder surgery in the middle) of finding parts, rewiring, and what I'm sure is only the start of a carburetor odyssey, I've finally taken the 500k2 on a ~10 mile loop around town, up and down some hills and along some traffic. Didn't break 40mph but I don't trust the bike fully yet.

Nothing fell off! Didn't stall! No leaked oil!

Some questions for you experts:

1) towards the end of the ride, the oil pressure light started coming on at stops. Indicative of needing a new oil pump? (It's now dark out so I'll check my oil level tomorrow)

2) The throttle is, let's say, not very sensitive. You really need a handful sometimes. Maybe I'm just too used to modern bikes. Is there a throttle tube/housing or other mod that is commonly used to increase the circumference of the pull?

3) The brake lever is a little too stiff: I can only pull it about 1/3 of its range, and the braking power leaves something to be desired. I did a full front brake rebuild with a braided steel line, and it's a stock MC which I believe is a 14mm bore. I'm thinking a 12mm bore would transfer more power to the caliper (longer travel of lever = higher ratio of force). Is this a common change, or is there a good reason to not make this change?

4) I let the bike warm up for a few minutes in my driveway, and adjusted the idle to about 1.2k before leaving, but as the bike really heated up the idle kept creeping up, I had to turn the screw out a couple of times before it would stay. Normal behavior, or indicative of some problem?

Thanks folks,

[newday777]

Congrats.

1. Possible bad oil pressure sensor. Replace it. Be sure no chafed wire.

2 & 4. Sounds like carbs not cleaned and set properly. What process did you clean with?
Did you clean and reuse the honda/kein brass? Or did you put in cheap aftermarket kit brass and float needles?

3. Did you bleed the master at the banjo bolt before you bled the caliper?(known as bench bleeding the master cylinder after rebuild/empty reservoir)

[dave500]

im with new day on the oil pressure sender unit,the brakes were like that new,very wooden and squeeze hard for not much gain,the long sweep throttle is the way it is,if you crank em open quick smart itll gulp air go lean and bog down,just cruise this bike around compared to modern bikes,you have all the factory airbox in  place?before you #$%* around with the carbs be sure the ignition is spot on!!!youll chase your tail everytime,ive repeated this over and again for years,get the ignition spot on first before you #$%* around with carb changes or adjustments!!

[Deltarider]

4. It's normal behaviour.
I'm with Dave on the ignition. As I've said I don't know how many times: check and doublecheck the ignition, all aspects. Even verify the IGN switch is still OK. In this forum the time spent on carburetors is not real! When carbs have been inactive for a real long period of time, yes, you can expect some maintenance to be done. For the rest they are dead reliable and do not require any adjusting. I can't even remember the last time I had a look at my carbs. O, yeah, recently, but that was to try out a simple test to verify fuel levels for CB500/550s that have the oldstyle carbs.  http://forums.sohc4.net/index.php/topic,185754.msg2151647.html#msg2151647

[gmoss]

Thanks for the answers guys.

Newday and Dave, I'll check out the pressure sensor, good thinking.

Newday, I did not bench bleed the MC. I'll look into that, thanks for the tip.

The bike came with pilot jets from a CB500T, which were 7mm too short, so it had no pilot circuit. I replaced mains and pilot jets with Keihin brass in stock sizes (100 and 40), left the float valves as they were, just cleaned a little. I think they're Keihin but not sure. I did read the thread about undersized O-rings on the main jets but I think all of mine are pretty snug.

Dave, yeah, stock airbox and filter. I'm inspired by this thread: http://forums.sohc4.net/index.php/topic,183277.0.html to try to make it a bit more serviceable, but I'll find an ebay air cleaner to play with once I'm happier with how the bike runs stock.

Delta and Dave, bike came with Dyna-S which I know was installed 3 years ago by Chris at Limey Bikes here in Austin, so I never bothered checking it, but I guess it can't hurt to be sure. It'll get done this weekend.

[dave500]

good its got electronic,just use a strobe to be sure the advance unit is working,with a warm motor shine the strobe as you increase rpm,youll watch as the mark moves,keep slowly increasing rpm untill the mark stops advancing,it should be between those two marks or more toward the right hand one,if not adjust it,forget where ever the mark ends up when its idling,forget about the "F" mark.enjoy.