Carb balancing

[beemerbitz]

Thats really kind of you matey. I dont mind paying you for fuel/time etc, i'm at a point now where i want to get the bike up and running ready for an mot. I've sent a cheque to Rick Oliver for a set of inlet rubbers today as the others on closer inspection are probably past their best and look worn/deformed in places. As soon as they arrive i'll probably be dropping you a pm. Thanks again to everyone for their help.

[Neosophist]

The revs do hang a bit when the throttles shut and wont idle at less than around 12-1300 rpm even when warmed up off choke. The bike bogs when the throttle is cracked open as you say and slowly returns to idle speed, doesnt drop below and pick back up again. Would the bike running lean make the plugs really clean looking as when i took the rear 2 out they look like brand new. They are brand new but i'd expect to see something on them by now and theres no deposit of any kind.

Is it actually running on the back two?

You should get deposits straight away.. are the exhaust pipes hot? (DONT touch them) touch a wet cloth to them.. if you dont' get tonnes of steam wet your fingers and tap them to asscertain temp.

And hanging is a sign of air-leak (lean mixture)

Perhaps its not running on all 4 and has an airleak!

[beemerbitz]

It's definately running on the back 2 ( i touched the exhaust to see if it was firing on all 4 , wish i'd seen this post before i did ). I'm going to re trace everything i did to the carbs and check and double check any seals and o rings. Also going to replace the inlet rubbers and see how i get on from there. I spoke to Rick O last night and he seems to think i've missed something silly. Probably have as this is the first time i've rejetted multiple carbs.

[beemerbitz]

Inlet rubbers arrived today, and i've fitted them to the bike,refitted the carbs and tank and retried running the bike. The bike is a lot better but still not right. Its bogging low down when opened up and still seems like the ignition is retarded and struggling to come on song.I havent got a clue what i've done wrong to the carbs. They've been stripped and re checked several times now, I'm starting to wonder if it could be electrical.

[Neosophist]

Inlet rubbers arrived today, and i've fitted them to the bike,refitted the carbs and tank and retried running the bike. The bike is a lot better but still not right. Its bogging low down when opened up and still seems like the ignition is retarded and struggling to come on song.I havent got a clue what i've done wrong to the carbs. They've been stripped and re checked several times now, I'm starting to wonder if it could be electrical.

It sounds like it could be too rich / too lean.

What did you change in the carbs?

[beemerbitz]

I changed the rear jets to 122 from 118, the fronts from 115 to 120, drilled the slides to 2.5mm and turned the screws out to 2 and 1/4 turns from fully in. Would you suggest returning the carbs to standard or maybe using smaller jets?

[Josh312]

arite mate i think ive got the same problem as you ive put bigger jets in and cleaned the carbs 5 times now with an air line goner start looking for air leaks at the weekend if i find out what it is before you i shall send you a msg

[Josh312]

arite mate you had any look

[beemerbitz]

I've not yet matey. I've had a break from it for a couple of days, my head was battered. If you can sort yours i'd appreciate it if you could let me know what it was.

[Cammo]

The bike is a lot better but still not right. Its bogging low down when opened up and still seems like the ignition is retarded and struggling to come on song.

Silly question perhaps, but have you let the engine warm up properly before revving it?