Another BS34 problem

[Jimbo W]

You may recall, I'm the goon who, not even drunk, drilled the left side carb on my '80 G, in the protrusion just above the throttle stop screw thinking it was the capped-off location of the mixture screw. It was weeks ago & I still can't believe my impetuous stupidity. I epoxied a tiny bb to seal the hole but guess what - it won't run on that side. Sure it isn't electrical (there's a spark), new plug cap, fully charged battery. Fuel runs out of the float bowl drain, mixture screws are both on 3 turns out (found them eventually) - they were much further out, maybe 5 turns. Have blasted carb cleaner through the intake but, while the right cyl is as strong as ever there is nothing from the left. Plug is not getting wet. So, what do you reckon I've done & can I save my carb? Blocked jet? What are the symptoms of a split carb diaphram?
Thanks in advance if anyone takes pity on me.

 

[angus67]

You stuck the bb in too far. Blocking that passage. Drill it back out, clear what u can out of the passage and try again. Does the problem side fire if you work the throttle?

 

[Jimbo W]

Here's what I did. The end of the casting pinged off across the garage & I just can't find it. If I could I'd have epoxied it back on. Can't get it to fire if I work the throttle. what is under the bb - an empty passage is all I could see?

 

[gggGary]

From memory that passage brings air from the air jet in the intake bell turns 90 hence the plug after drilling, and supplies it to the main jet, emulsion tube area to mix with fuel and aid in atomization/ flow, If not that, it sounds like a good answer anyways. I'll go look to confirm.
Basic diaphragm check; with choke OFF. raise piston with finger cover half moon port on top of intake bell with finger. let piston drop if diaphragm is good it will ssllowwllly drop, not plummet down.

 

[gggGary]

There is a tiny jet hole in front bottom of float bowl that supplies fuel to choke and idle circuits. Easily missed, often plugged.

 

[5twins]

I think that's the air jet passageway to the pilot jet, not the main. It looks like it runs to the jet that's removable, and that's the pilot air feed.

 

[gggGary]

Darned 5t always pointing out those blasted DETAILS LOL

 

[Jimbo W]

Well, many thanks for the replies so far. Although I don't quite recognise that carb as being the same as mine (or is it pictured from the other side?) are you guys telling me that the section of casing that pinged off & appears lost forever contained an orifice that is essential to the carb's operation which is now blocked off? Have you got a photo of the left side of the left carb?
I'm going to have another go the find the piece - it might even be in the vac cleaner as I like to keep the garage nice!

 

[gggGary]

Good eye, that's a stripped down "RH carb" from an 81, but the passages and drillings are identical.
If you can spray carb cleaner in the bell through the rebuilt passage and it sprays out by the pilot, you are good. If not you gotta redo or find a diff carb.

 

[Jimbo W]

I still can't find the broken off piece, it wasn't in the cleaner.
From my photo does it look like I've lost the passageway to the pilot? I haven't found a photo of an identical carb to compare the casting. I think I must have screwed it or the bike would still be running on that side. Going to be hard to find a replacement body.

 

[gggGary]

No it "looks" fine but if you goobered epoxy behind the ball you may have plugged the passage, did you spray carb cleaner make sure it goes through from bell to pilot? How about the diaphragm test?

 

[Jimbo W]

I'll go & try to remove the ball. Carb is on bike still so can I do the carb cleaner test? Need float bowl off at least?

 

[gggGary]

Gas off, float bowl drain open, spray carb cleaner in the intake it should come out the float drain. That'd be enough to prove the passage is open. If it just sprays back in your face, the hole (and you) are blind.....
an oil bottle cut to make a fuel catch is handy.

 

[Jimbo W]

Ball came out easily, cheap Chinese epoxy, then a tiny drill cleaned out the goop from the passage. Carb cleaner squirted through intake came out of float drain!! Deep joy. Now, what do you suggest for plugging the hole in the carb body? My last effort was not good. Altogether just about the stupidest 2 wheeler episode I can remember but if you've rescued me then I owe you at least a meal & a few beers!
Got 5 new stitches in kickstarting leg so will leave it another 24 hours before trying to start her up. Don't like to use the e start from cold.

 

[gggGary]

it's low stress, a ball just big enough to not "fall in hole and a BIT of JBweld on the outside? Buy original formula JBweld it sets slower but is much stronger. how about grind/file a small short sheet metal screw VERY short then the JBweld or clip/grind off a "right diameter finish nail very short. they have a small head.

 

[5twins]

In warm weather, the electric leg should fire the bike quite readily. I only use the kicker when the weather's cold, like 50 or high 40's, or below. The batteries aren't real big on these and don't have much reserve. They'll run down quickly with sustained electric start cranking. The ignition needs voltage to function too. With the battery run low, even if the electric leg is still cranking, that may not leave enough voltage left over to power the ignition. It won't start, but a kick or two will usually start it then.

 

[Jimbo W]

Battery is fully charged, starter makes a horrible bag of spanners noise sometimes so I generally only use it if bike is off the centre stand.
Gary, I guess as a temporary measure to make sure she does now run on both sides, I could just plug the hole with blu-tac (do you get that over there?) Also, don't know if we get JB Weld here - I've got some Chemical Metal (2 part stuff) which is possibly similar.

 

[gggGary]

sure 2 part gray epoxy SB fine.
Read up on starter spring squeeze, usually fixes starter grinding "easy" n free.

 

[Jimbo W]

Started her up this morning (on the e start but leg ok to use the kicker now) but still no left cyl. Removed the blu-tac temporarily covering the hole & fuel spat out when she coughed a bit. Did a bit more digging in the casting & can now see I have 2 small holes. Is this how it should look?

 

[gggGary]

Not sure what you are seeing, saying here Jimbo..........