Surging

User avatar
PaulD738
Posts: 3962
Joined: Thu Sep 25, 2014 6:57 pm
Location: Warrington Cheshire

Re: Surging

Post by PaulD738 »

Alan H wrote: Thu Aug 05, 2021 11:42 pm Not if the carbs are set properly. GT550s don't surge and they don't have cv carbs. Dunno about other models as I haven't ridden them, but the 750 is the only 2 stroke with cv carbs.

Low tickover and non cv carbs is the answer. People tend to forget that we used to ride 2 stroke more aggressively ,'back then' and now most of us think ££££ when YOU ride them. 2 strokes like to be revved, bolox to fuel economy at less than 4k rpm. If you drive like that, get a 60s BSA..
My old GT750 J had Mikuni VM32 slide carbs and suffered no surging whatsoever, my T500 is also fitted with the same VM32 carbs (a kettle is just a T500 with an extra cylinder) and again no surging. As Alan says correctly balanced carbs set to a low idle shouldn’t give any problems. Both my kettle and 500 idle at a tad less than 1000rpm. I’ve found a low even idle is achieved by ensuring the slides are set at exactly the same height from bottoming out then turning the idle screw until the slides just start to lift, I then turn both/three screws the same amount half a turn at a time till the bike idles smoothly. Simples like me
This is done prior to synchronising the carbs.
They're rubbish them Jap bikes lad they won't last five minutes! you want to get yourself a nice Royal Enfield!
A quote from my old dad 8-)

I started out with nothing and I’ve got most of it left!
willowden
Posts: 167
Joined: Thu Nov 16, 2017 3:10 pm

Re: Surging

Post by willowden »

When I fitted the Accent ignition kit to my GT750 the surging was eliminated. There must be a connection to the three spark plugs firing at the same time . Maybe burning off any unspent fuel ? Who knows , but it cured my surging & the timing was spot on previously as well.
User avatar
Dutch
Posts: 756
Joined: Thu Jul 28, 2011 8:28 pm
Location: St Helens Merseyside

Re: Surging

Post by Dutch »

Thanks for your prompt comments guys.

I will definitely have a go at the wiring Teazer to get my idle speed down because it frustrates me having to keep the throttle open when stationary, but I have a new wiring loom on mine, do you know if this will be any different from the original?

I don't fancy fiddling with the carbs to be honest Paul because the surging isn't that bad and if I successfully carry out the above mod to get the idle speed down it may remove the surging completely so let's see. It's going to be a couple of months anyway and more questions may follow so will keep you posted.

Thanks again
Jeff
GT750A
User avatar
Alan H
Posts: 12104
Joined: Fri Aug 05, 2011 6:38 am
Location: Wombwell, Republic of South Yorkshire

Re: Surging

Post by Alan H »

Dutch wrote: Sat Aug 07, 2021 10:48 am but I have a new wiring loom on mine, do you know if this will be any different from the original?
Some of the after market wiring harnesses have thinner wires & smaller plug socket connectors, so even though they are new, might not be any better than the old originals as fitted in the factory.
Proof that four strokes are over complicated
Post Reply