V50 Help

[Scout63]

My new to me ‘80 V50ii is acting funny.  When riding at 3/4 to full throttle it suddenly gets much more powerful, just like a two stroke coming on the pipe.  It kicks in and out of this mode.  I just rebuilt the carbs and cleaned all passages and jets carefully and set the valves. It starts and idles well and throttles up the range well except for this issue. Pipes are Bubs. I put a timing light on it and the ignition appears to advance on both cylinders properly in neutral and not under a load. I have two theories:  1. Float levels are too low. Both were about 25mm whereas the shop manual calls for 23.5mm. Theory 2. The electronic ignition is cutting the advance in and out.  Is this possible?  I wouldn’t think the advance would cause such an abrupt and significant increase in power.  Any input will be much appreciated.

My other issue is that the clutch plates stick fairly significantly.  When first using it for the day I have to break them free with several drops into first while holding the brake on.  When riding, I have to pull the clutch in and rev the throttle several times to get them to free up when coming to a stop or down shifting. It’s not an adjustment issue as I adjusted the cable with some free play. I think it may be the result of the bike sitting for about 15 years before I got it.  Any input on this also appreciated.  Best to all.  Ben

[pehayes]

Regarding the sticky clutch plates.  It is likely from oil contamination.  Use it for awhile and you might get lucky.  Otherwise, the oil source would be transmission oil getting past the throwout shaft seal or engine oil getting past the crank seal.  Most likely the former.  If so, you're in for a lot of work.  Disconnect and dismantle everything that isn't a transmission in order to get at the seals.  Sorry.  :-(

Patrick Hayes
Fremont CA

[jacksonracingcomau]

Clutches  with oil on em only slip down here
More likely is adjustment at rear of box, on the actuating arm, easier with swinging arm off but doable on
Back cable off completely, adjust at arm, readjust cable.
Very frequent topic on this forum , SB clutch adjusting.

Re advance, i can’t remember if v50/2 had electronic ignition std, certainly the /3 ran points, commonly replaced with a Dyna electronic. These use the original mechanical adv/retard .
If you have this, they can stick, doesn’t sound like the problem but if you have one, a clean and lube should eliminate it as cause. Should spring back nicely, move freely etc.

[Frenchfrog]

Your v 50 probably still has the electronic Bosh system common to Ducatis etc on it...they do work but it must be getting old by now.Mine had a hole at around 3500 and that seemed to be consistent with all of them..nothing that you describe though. Check the wireing and the earths..if you could replace it with an alternater mounted Sachse de  ignition unit if it is that..I had cut outs that were due to the ignition swith breaking up on mine so that's worth checking...at that age there are so many possibilities that the only way your going to cure it is by going through every single possibility with a fine tooth comb. Pleas post the results as that can help someone else!!

[Scout63]

Thanks for the help.  I’ll work on it and report. It has the Bosch electronic ignition. I’ll adjust the float levels first then dig further.

[Antietam Classic Cycle]

Just went through some of this with a customer's V50. Air gap between the magnetic pickups and the "trigger" can change advance dramatically. Set it as close as possible. If you can find one of the factory tool that slips onto the crankshaft in place of the trigger, that's the best way to set gap and timing. Even when everything is set correctly, the advance is still not a gradual curve, more like a sudden spike at 5k rpms.

[Scout63]

Thanks Charlie. It also has a hole in the breather elbow.  I’m going to replace that first, set floats second, check pickups third, with some test riding in between. What a sweet sounding and handling bike.  Everything about it feels right.