bike won't run smooth when holding throttle

Hi everybody

First i want to thank you all for the help on other topics learned a lot of it, but now i've got a problem and i couldn't find a topic about it.
I have a 72 combat completely rebould boyer ignition and powerbox, carbs refurbished, new rotor,stator and wiring, engine done by a pro.
Here is the problem it will run on first kick and idles ok when i twist the throttle and release it it revs ok but when i hold the throttle above 2000 rpm it starts to sputter first it was the left side and after some tinkering it now is the right side and to be honest i don't know wat i've changed.
I hope somebody can HELP.....

Hi, some questions first

can we assume your battery is fully charged and fairly newish?

and can you tell us what carb set up you have, single Mikuni, dual Amals?

plugs, just to verify can you pull them both and see if they are blackish fouled and gapped correctly?

then we can better help?

If you still have the boyah supplied trigger wires then you are on you own until you verify they are not broken inside insulation and if not then you are still on very thin ice that they will remain that way by the time it gets warmed up again.
Put connected plugs on head, switch on ignition then beboop and tug tap various wires areas and listen-watch for a spark snap. Its normal to get a snap on key off/on but not otherwise w/o engine turning. Try that test on center stand in gear for extra Commando dancer thrill but keep fingers clear. Cam chain slack might do this too. Float bowls sucking in air have done that to me, ok on idle and throttle up but misfiring suging to hold a steady legal pace, same with manifold gaskets and loosened fasterners unknown as checked not that long ago. I've also had identical symptoms d/t a flailing Earth strap in tail light flapping-tapping shorting to power that lowered bayah brain IQ volts to advance/retard all over the scale, till finally died and eventually found the carb misfire coming from under the tail lens. A real Sherlock Homes trainer, eliminating all obvious logical things then must start looking at the illogical to the case. This ain't only reasons I'll never give boyah boxes much respect anymore. May you not have reasons I have as boyah can last indefinitely and ones I had are now on someones else's ho hum smooth runner.

battery is new and fully charged
running amals everything new but floats
plugs are black and sooty

Choke slides are 'UP'?

Bob Z. said:

Choke slides are 'UP'?

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choke slides down

either put new plugs in or really clean good those fouled plugs, test ride, and report back

Choke slides down means your chokes are on, pull them up and it should run good again, I took my chokes out of my Amals over 36 years ago, it don't get that cold here where I live, but you have to blank off the hole where the cables enter.

Ashley

1up3down said:

either put new plugs in or really clean good those fouled plugs, test ride, and report back

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i'll try new plugs and look for loose wires and let you know

cheers

ashman said:

Choke slides down means your chokes are on, pull them up and it should run good again, I took my chokes out of my Amals over 36 years ago, it don't get that cold here where I live, but you have to blank off the hole where the cables enter.

Ashley

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feel a bit stupid now

hope that solves the problem

sorry too trouble you all

dont feel stupid everybody does something silly now and then, i once read that the reason t160 tridents didnt do too well with the Saudi arabia police force was because they rode around with the chokes on all the time and discarded them when they conked out! thats when MCS in leytonstone high road north london repatriated them back to the UK

baz said:

dont feel stupid everybody does something silly now and then, i once read that the reason t160 tridents didnt do too well with the Saudi arabia police force was because they rode around with the chokes on all the time and discarded them when they conked out! thats when MCS in leytonstone high road north london repatriated them back to the UK

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Yes Legrande ,do yourself a favour and remove the choke assembly and chuck it as far as you can toss it. Carb-top entry points must be plugged. The lever is cool looking though...

Torontonian said:

Yes Legrande ,do yourself a favour and remove the choke assembly and chuck it as far as you can toss it. Carb-top entry points must be plugged. The lever is cool looking though...

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"IF" you ever run something like a Mikuni, the choke lever works great for operating its fuel-enrichment (choke) circuit during cold starts. And, like Torontonian says, they look cool. I wish I hadn't tossed mine so many years ago... :roll:

You guys are so kind! Wondering whats wrong when running FULL choke hot! But one better than this; a few years ago my mate comming back from the IOM , its 2am [he got the midnight ferry to Hysham] any way its dark,raining and he's 5 miles from home ,with his mate on the back,
The bike splutters to a stand still, 2 miles from the next town....so he concludes the bike as run out of petrol. Leaves his mate to look after the bike and walks the two miles in pouring rain. He buys a can from the fuel station, fills it and starts to walk back, just then a taxi stops and he jumps in..it's £5 back to the bike...taxi driver was going that way..so a extra £5 is his bonus!
When he gets back to the bike his mate hade been "Having a look" he said " whats the other tap for " "other tap?" my mate replied...yep you have guessed it..it was the reserve :!: turned it on and the bike fired up.....now thats what i call stupid! walked over 1 hour in pouring rain, bought a can [£10] fuel, and £5 taxi fare...so running with the chokes on is stupid!...next he will be complaining the lighs are poor..with the switch on pilot!!!
Sorry to be harsh, its my mood this week, some customer complained my damper kit had reduced his forks to become very stiff and no movement. he had fitted a Commando set to a N15 with 25 inch stanchions! He said the expected the kits to fit any forks..now what do we think of that statement?

Pretty funny, but we all make mistakes, it just a thing with our Norton motorcycles we all learn by our mistakes and we all learn something new even after 37 years of ownership :lol:

Ashley

I love my choke slides. Those 40 degree, damp mornings and a full choke!

Russ

Cheers everybody took out the slides and made my first few miles whoehoe

john robert bould said:

You guys are so kind! Wondering whats wrong when running FULL choke hot!

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ashman said:

Pretty funny, but we all make mistakes, it just a thing with our Norton motorcycles we all learn by our mistakes and we all learn something new even after 37 years of ownership :lol:

Ashley

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I have no idea what the OP's experience level is, but, if you weren't brought up with old vehicles then chokes aren't obvious things to look at. Modern (i.e. EFI) bikes and cars don't have them. And the Amal's choke (air slide, they call 'em, actually) is counter-intuitive: It defaults to closed, and you have to open it to run, which is a bit daft, when you think about it. If your handlebar lever is a bit loose, it can vibrate itself shut, too.

legrande said:

Cheers everybody took out the slides and made my first few miles whoehoe

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You did put threaded plugs in where the choke cables go, didn't you?

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