Popping and surging at higher speed.

Hi all, I bought my 95 with 25k miles on it a year and a half ago, had issues at the time so did a rake of bits to it. including a copper plate to the back of the RR and a direct earth to same. Stripped cleaned and rebuilt carbs in ultrasonic bath, including a broken joint, new fuel filter , oil filter air filter, new starter motor. Checked the full charging system and battery was good, alternator putting out 5.5 v per wire, RR distributing 12.3V out to battery. All this is still the same charging wise.
My issue is when I rebuilt the carbs I only had the idle mixture screws at 2.5 turns, this resulted in the bike dying when I came to a stop. So I recently turned the idle mixture screws out to 3.5 and replaced the exhaust collector and downpipes. I still have the laser exhaust on it. since these two changes the bike hasn't cut out any more but it has started to surge and backfire on acceleration , the backfiring is constant but the surging only occurs if I am pushing past 6k rpm past from 90mph, or if I am taking off again after cruising above 60mph. I thought first a charging issue but tested RR and alternator and battery and getting good results from that. charging at 14v battery above 10v at turn over and 12.3v at idle. Alternator still outputting 5.5v on each lead and RR still putting out 12.5V at idle. I took apart the fuel pump to check the fuel delivery which is 2400cc the solenoid in the fuel pump seems to be firing with no issue. My thoughts initially was fuel pump but now I'm stumped. I've searched the forum for this problem and found one discussion about it from 2012 but no follow up. Any help please?

 

FYI European model so no Cali crap to take off it.

 

I'm going to say Carb Synch.

 

I wish, Carbs were bench synched and then synched while running. although not synched since I turned out the idle mixture screws, would they change that much from idle mixture screw adjustment.

 

If you have to go more than 3 turns out on a pilot screw, you need to go up one on your pilot jet. I'm not saying that's your problem, but when you go back in to the carbs to verify your work, consider it. Especially with an aftermarket exhaust.

 

Right so. I thought standard position for idle mixture screws was 3.5 out?

 

you have popping, surging & backfires - We can all safely say its carb related.. lol
I'd start with the synch as that can be done on the bike. Could pull all the plugs first to check the colours

 

Coolio, I'll get to that this weekend and let ye all know how it goes.

 

This may (or may not) help. You can make each cylinder the same, which is the general advice on here. Or you can follow the manual and set the mixture for each carb. But you'll need an accurate tacho'.

I've had better behaviour after following the manual, ymmv.

From the Honda manual:

 

How're ye all, Simon thanks a million for posting that. I didn't see it until now. I eventually got my carb balancing kit after getting a box of nickers and bras instead from ebay. Anyway got the carbs balanced on saturday and rode the shit out of her sunday.... and monday..... and today. She's running like a dream now and thanks all for the advice, i didn't buy the carb screwdriver and burned the bejasus out of my hand to get it right, but it's all worth while.

 

I didn't get one for 10 years.. Burnt my hand the first few times, wore gardening gloves for a long time. Since I got the tool I can adjust at any time with zero pain and it works pretty well - wish I'd done it 10 years ago....