IOM issues with Rotary Norton when hot?

[David Brown]

Hi all,My Norton Rotary Cafe Racer was running fine until I went to the Isle of Man. I had it shipped over to Tony East's museum in Kirk Michael in April and I then went over in June on my ZX7R. I then had two bikes to play with which was a dream come true. I collected it on the 6th June. It hadn't been charged for over a month, but thankfully my Gel batteries had enough juice to start it. It sounded great and always drew a crowd.My bike proved very popular everywhere I went and had loads of people wanting to take pictures every time it broke down. Which was generally each petrol station. It started on the button (when cold), ran ok but whenever I stopped at a petrol station, it wouldn't restart. It would turn over fine, but just would not fire. At one point it wasn't sparking too well so I found a bike shop and fitted 2 new CR8EA's which worked great. Big sparks. I even got it started once cooled and made to the Laxey Bike show, 3 hours late. But they let me in - just. And it generated much interest. It was Molyd about a thousand miles ago. Everything else seems ok.Each time fuel seemed to be getting through, judging by the amount it was chucking out the exhaust. I even took the plugs out several times and in the plug caps cranked the engine over and caused a huge fireball, to gasps from the bystanders as the unburnt fuel nearly took out at least 3 petrol stations in the IOM. That would have got me and my Norton noticed but for the wrong reasons. I explained it was a Rotary. Ahh they said.I met some lovely people all trying to help. You meet the nicest people in petrol stations.When everything was ok again.Someone suggested crap IOM fuel but my Kawasaki was fine so I think unlikely.Only made it round the Mountain once which was disappointing. It even stopped in the main Ramsey corner layby and it would start. I didn't like to be rude to people who were interested in talking and taking pictures of the bike but I just wanted it to start and was getting very frustrated.Any ideas anyone?It is on its way back from the IOM, I hope to have it back in sunny Sandhurst by this Sunday, at which time I intend to get to work on it.Maybe even make the Norton Owners gathering at Brooklands Museum early July.Please let me know if anything sounds familiar and anyone has any ideas.Many thanksDavid Brown

[wust588]

Hello David,I can't quite make out what sort of Norton rotary your cafe racer is, ie Classic / Interpol or Commander based, butit seems likely from the number of petrol stations you visited, that the engine is running very rich! In fact it sounds like it is flooding. A faulty fuel tap can cause flooding, and a sticking choke or damaged choke "O" rings or worn float needles can cause richness.How far does the bike go between fill ups?Do you get neat fuel dropping from the joint between the silencers and manifold?

[Dell Boy]

I got rid of my F.1. because every time I pulled away from a stop or traffic light it cut out in the middle of the junction & then after a couple of seconds it would burst into life on an open throttle & hurl me back into the traffic at high speed. I put this down to the Mikuni carbs being mounted directly above the extremely hot exhaust collector box resulting in almost total fuel vapourisation in the carbs leaving nothing to call on when the throttle was opened.I never had trouble starting as I recall, hot or cold. Another reason I disposed of it was I got fed up with the endless onlookers wanting to talk rubbish about it. I used to park up & run away. I did see one in Peel by the lifeboat station this year. Had damaged indicators.I actually bought mine from a millionaire in the Island. It had a smeared engine despite having had a recent rebuild. I had it rebuilt at Shenstone.I didn`t get enough smiles per mile when out riding it so I sold it to a guy from Gillingham, Kent.Derek Fox.

[Wayne]

DavidI had similar issue to Derick, however as I owned my f1 from having only 600 miles on the clock in 1992 knew it was not a designe issue, I change to a new ignition new carbs but no difference at all, it would stall a traffic lights once warm, occasionally refuse to start in this scenario, after 2 years of getting worse and needing longer and longer to down after I puled up some wear before it would start again, I was at an end as it was becoming dangerous cars behind expected me to set of and I just stalled.Finally the mysterious faulty component gave up the goast, the ballast resistor, everyone I spoke prior to said it was not this what was causing the issue, and I would agree until I change it, however problem stopped when I changed it. I changed over £400 on parts when a £20 part was at fault. I should point out with the top bodywork off on the troublesome Lucas ballast resistor the bike would not stall, heat was affecting the ballast resistor with the bodywork on. My f1 sport ballast resistor failed all of a sudden with the normal symptoms for this component, so I understand if people dispel my f1 experience, but it happened.note for f1 owners your vacuum pipe elbows will be leaking by now, I blanked of my own off with high temp silicone blanks no issues att all now and a f1 that ticks over despite been mollyed in 1995, total cost of parts £25 including a new ballast resistor.Derick how many times when you went out on your f1 did you have oil drips on your collector box leaving the tell tail dried run marks?Regards Wayne

[Dell Boy]

Hello Wayne,I dont recollect any oil stains on the collector box but, as people who know me will testify, i am not much of a cleaner/polisher of motorbikes so I rarely looked at it & it wouldn`t have bothered me if it was stained. This was all about 20 years ago so memory is hazy.I have had ballast resistors fail on Commanders & have mounted them up in the nose cone to get a cooling breeze over them.Derek Fox.

[Dell Boy]

Just thought. If the bike did actually cut out & not chime in again I only had to hit the button & it would fire instantly & I would carry on until the next set of lights where if there for any length of time I went through the same scenario. Derek Fox.

[Wayne]

Hi DerickIf you had no oil marks you were not riding it hard enough, and the less you clean the more noticeable it wold be. Its the first think I look at when I see a F1.I have a Nrs gearbox and it has a plate inside to try and stop the oil leak from the breather.Regards Wayne