Hi all
Recently I did quite a bit of work on my bikeb(M20) as it misbehaved badly in France in June
After this I have covered nearly 600 milesvwithoutbso much as a missed beat - until yesterday on a local spin it refused to start
I had just refuelled (98 octane - texaco) after a trip of approx 10 miles or so from home - I rode 500 yards to local riverside tea house, it was closed, so went to start - nothing - not even an effort to start
Items checked
Fuel at carb
Fuel at plug
Spark at plug
Changed plug
Checked ht lead
Opened fuel cap in case of blockage
Good compression - can stand on kickstart
Points gap good
Timing accurate
No evidence of head gasket blow - solid type
Valve clearances within limits in shop manual
It has never let me down so badly before so I had to resort to the dreaded Carole Nash recovery - while I was waiting I tried once more & on a 10 attempt or so it caught & fired - cancelled the call out & rode home. When I got home I started & stopped her 5 times effortlessly even with the old plug fitted. I suppose I had been pulled in for 1.5 hrs, so cooling will have taken place during this time
2 things here
I fuelled up with new fuel - a good brand & a busy outlet in maidenhead - have used 98 before with no problems - unlikely to be a problem ?
Magneto - could ths be the start of a condenser showing its age - although it has performed faultlessly for many years I know it has a time limit - does this breakdown of the condenser occur very rapidly, is it a gradual worsening process or could it happen like for me yesterday just out of the blue
Am just keen to learn of other rider experiences, I must somehow avoid the shame of being loaded onto a breakdown wagon
Would appreciate your feedback
Best regards
Job
email (option): Jonnyob1@googlemail.com
Hi John,
I would definitely say it is a magneto problem, all my old M20s had this problem start from cold no problem after a good run and a short stop they would not start, a good bump start down the road with the engine spinning and they would start. If you leave them 15 mins to cool down they started.
On all of my restorations i fit reconditioned armatures, the new capacitors that are fitted now are far superior to any lucas condenser, even if you find a new old stock lucas armature stay clear as the condenser will have perished with age.
Use a good well known magneto expert, if you feel confident in striping your mag down just send the armature but if you do you may have to re shim the end cover if he fits a new slip ring, and don't forget to fit a keeper to the body to keep the magnetism, an old armature will do this.
You will me amassed at how a good magneto will change your bike.
Tim W
email (option): t.j.walker@btinternet.com
Hi Tim
Thanks for your reply
I have had a magneto redone recently for my new m21 motor and fitted with a brightsparx external condensor, it's incredible the spark produced
As until now, I have left the magneto on the m20 motor believing in leaving well alone - it seems I have to get this one done too
It's most unusual as it took almost 1.5 hours for it to restart again, like you I have seen a cool down of 15 minutes or so to allow restarts but yesterday seemed an excessively long time to kick back to life
I will most likely connect a new condenser to try and for the experience of doing it,my feeling is the windings are in working order,
Best regards
Job
email (option): Jonnyob1@googlemail.com
Hi John,
The problem is that if you tried to fit a external condenser to try your M20 the faulty one will still be connected.
I have looked at the brightspark ones and they seem a good idea. But if you fit one you have to cut out the old one and re solder the connections together, looked at the web site it gives full instructions and looks easy, but i like a fresh start with a rewind new slip ring bearings etc it's piece of mind and it's worked well for me.
See how you go and let us know.
Tim W
email (option): t.j.walker@btinternet.com
A river-side tea house eh, John ? Did you cross the bridge without saying 'Good Day' to the little people ?
I use 98 where I can as it is supposed to be less likely to contain ethanol. I've seen no signs of fouling but I am still on NOS KLG plugs which may ? have glazed noses and be less susceptible to tracking.
Aah Rik
When in the RBWM - royal borough of Windsor & Maidenhead, there are no Caffs - just tea houses - what what what :-D
I fuelled up with 98' I find the bike runs better on it, at least I feel it does
I do feel,in this instance it's the magneto finally beginning to shout for help and a new condenser
It's just happened so suddenly and 1.5 hrs before I could start her again
Time to dig deep for a rebuild methinks
Job
email (option): Jonnyob1@googlemail.com