Topic: 18 mile first ride and plug pics question

[timdhawk]

Today I put 18 miles on my bike (first running after project completion). Just took it out to see if it would stay together. A few small tweaks and a few small leaks later she ran as great as I expected for the first run. Needs obvious carb tuning which leads to my question: how do these plugs look?

This is just around town, no real plug chops yet. 1-3 gear only and 1/8-1/4 throttle for most of the ride. Certainly that much on the last few minutes home anyway. Left to right is plugs 1-4.
#2 looks rich to me but the other 3 look maybe a little lean? What do you guys think?

[Johnny5]

From those pics, it looks a little lean.

[crazypj]

Have you had carbs synced properly?
#3 has some serious lean condition (side electrode is getting too hot and base of threads is completely clean)
#4 isn't a whole lot better
#1 looks a bit too rich at low throttle openings
#2 looks real nice, slightly rich but nothing serious for throttle position
 Side electrode should show a definite line where the heat travels (like #1 in pic)
 A picture under natural light would be better

[timdhawk]

Have you had carbs synced properly?
#3 has some serious lean condition (side electrode is getting too hot and base of threads is completely clean)
#4 isn't a whole lot better
#1 looks a bit too rich at low throttle openings
#2 looks real nice, slightly rich but nothing serious for throttle position
 Side electrode should show a definite line where the heat travels (like #1 in pic)
 A picture under natural light would be better

This particular set of carbs, I'm convinced, is a gremlin birthing ground...
Carbs have been completely cleaned and rebuilt and gone over 10-15 times in the last year for various reasons. I can just about assure as much as humanly possible that nothing is plugged on these.
They are properly synced within 1 inch Hg of each other on the sync gauge. Float levels are just about balls on:

Here's the rub in the floats however. Numerous times on the test bench while hooked up to a hanging fuel cell the carbs held gas without leaking. Now with the gas tank on and after each run, they piss like crazy from the overflow tubes. (didn't look at which one specifically yet) I have to shut off the petcock to stop it.

Pilot screws out 2 1/2 turns
Main jet = 118 (maybe 120???)
Slow jets bored out according to Hondachopper.com to fix low end leanness on 77-78 carbs with pods and open 4 into 1's
http://www.hondachopper.com/garage/carb_info/7778_pilots/pilots1.html

[Danno]

it probably is one of the center two and sounds like you have contaminants in your fuel that is assuming you are correct that the needles and seats are already polished and clean check the filter on top of the petcock and check the bowls for rust if they have rust in them it got there somehow

[seanbarney41]

...seems to me, float needles almost always leak intermittenly after a teardown/rebuild.  Imho, it just takes a while for them to kinda seat or wear in ...when they leak, just give the outside of the float bowls a whack with a screwdriver handle or something, make sure they are not dumping when the petcock is off or the engine is running, and give 'em some time...see what happens...

[crazypj]

Fuel levels look pretty consistent, #2 a little lower (so leaner)
 You may have an inconsistency in the modified pilots, did you look at them with a x10 loupe?
You may find the internal surface is smoother or rougher on different jets affecting flow, should be possible to adjust air screws to get everything even (although it will need either bungs welded into pipes or, extr long probe into individual pipes (not as accurate but close enough for low rpm)

[Rgconner]

Here's the rub in the floats however. Numerous times on the test bench while hooked up to a hanging fuel cell the carbs held gas without leaking. Now with the gas tank on and after each run, they piss like crazy from the overflow tubes. (didn't look at which one specifically yet) I have to shut off the petcock to stop it.

Pilot screws out 2 1/2 turns
Main jet = 118 (maybe 120???)
Slow jets bored out according to Hondachopper.com to fix low end leanness on 77-78 carbs with pods and open 4 into 1's
http://www.hondachopper.com/garage/carb_info/7778_pilots/pilots1.html

Maybe I am confused... but if you are checking the float level from the overflow tubes and not the drain screws, doesn't that mean you would always be overflowing?

I mean, if this works, that is a heck of a lot easier than trying to find threaded nipples for the drain plugs or some other jury rigging.

Edit: In another thread I read that the later carbs had integrated drains/overflows... so ignore me.

[Duke McDukiedook]

Oh, don't worry, we shall. 

[crazypj]

Don't the drain screws have a drilling to the overflow vent?
 Loosen the drains and the fuel comes out

[timdhawk]

Don't the drain screws have a drilling to the overflow vent?
 Loosen the drains and the fuel comes out

yes. that is correct.