A strange one

modelman · Post by **modelman** » Tue Jul 17, 2018 12:33 pm

Not too sure what section to post this, but here goes.
Complete strip down & re-build, first-kick, instant start, so not far out!!
Only rode around the block a couple of times, when it starts acting-up, a mis-fire, pulled the plugs, VERY sooty, then no spark, then intermittent spark, it already has new HT leads, new plug caps, so I fitted NEW plugs, started, ran fine for another couple of laps!!
Same misfire & sooted plugs!!
Stripped the carb (again) all looked good, but I can't identify the jet sizes as the numbers are too lightly stamped.
Float-level at 26.5mm
Air-jet perfect & set at 1/1/8 turn-out. Tickover nice & smooth, but colour-tune indicates a rich burn, & air-screw won't reduce it, hence sooted plugs??
Timing bang-on & set with light & at correct gap.
Here's an interesting one, when running (& mis-firing) if I pull off & hold the plug-cap away from the plug, a large spark jumps the gap & it instantly picks up & starts running perfect, put it back on & it mis-fires!!
I have tried another twin ( Suzuki ) coil, the same happens, so I guess its not the coil.

The only thing I haven't tried is the condenser, could it be that, should I re-new??

Do you think I should buy a carb- jet set?
Then at least i'd KNOW the carb is good!!
Good compression, no smoke, but I should add that it starts first kick but with NO choke.

Or have I missed something obvious??

rrietman · Post by **rrietman** » Tue Jul 17, 2018 7:31 pm

carb slides backwards? there is a right and left.
Good luck
Randy

modelman · Post by **modelman** » Wed Jul 18, 2018 1:17 am

Sorry, I forgot to mention, CA77 Dream, single carb.

G-Man · Post by **G-Man** » Wed Jul 18, 2018 5:33 am

Have you tried dropping the needle?

Is it a genuine Honda needle or a kit part?

Needle jet may be worn.

Correct inlet spacer with the strange notch in it?

G

modelman wrote:Sorry, I forgot to mention, CA77 Dream, single carb.

modelman · Post by **modelman** » Wed Jul 18, 2018 11:28 am

G-Man wrote:Have you tried dropping the needle?

Is it a genuine Honda needle or a kit part?

Needle jet may be worn.

Correct inlet spacer with the strange notch in it?

G

modelman wrote:Sorry, I forgot to mention, CA77 Dream, single carb.

1- Don't know as no markings, ordered new kit.

2- Don't know, ordered new kit.

3- I'll have to take it off again to identify, its a brown 'Bakelite' thing with O ring recess, whats with the 'strange notch' then??

rrietman · Post by **rrietman** » Wed Jul 18, 2018 1:16 pm

I have had success in your situation by progressively lowering the float level until you can get a correct fuel mixture (if all the jets are correct). I don't know why, but it works.
good luck
Randy

G-Man · Post by **G-Man** » Thu Jul 19, 2018 2:27 pm

Modelman

I try and clean & reuse all the old jets & needles as the kit ones often give problems.

If you look at the flange side of your carb there is a cutout on the bottom edge. The correct spacer as a cutout to match it.

G

modelman wrote:
G-Man wrote:Have you tried dropping the needle?

Is it a genuine Honda needle or a kit part?

Needle jet may be worn.

Correct inlet spacer with the strange notch in it?

G

modelman wrote:Sorry, I forgot to mention, CA77 Dream, single carb.
1- Don't know as no markings, ordered new kit.

2- Don't know, ordered new kit.

3- I'll have to take it off again to identify, its a brown 'Bakelite' thing with O ring recess, whats with the 'strange notch' then??