CARBONE IN THE ENGINE

[johnbirchjar]

Hi guys,I have read somewhere on this forum of our rotory engines being somewhat cloged by carbone deposites only discovered when they are striped down,are there any early warning indicators of this? and is there anything that can be done about it?(I remember as a teenager in the late 1950,s that we used to give our bikes a "lasymans de-coke" by getting one of your mates to "ride shotgun" and squirt Redex through the carburator bell mouth while blasting off down the road at a high rate of knots,the clouds of smoke that accompanied this manouver was quite impressive!) do'nt suppose that I dare do that to the Classic, allways assuming that the old girl is in need of a "de-coke" anyway,Regards J.B.

[MrB]

Running the motor at a healthy speed so the carbon doesn't have a chance to stick works for me Johnny

[graham]

There's always some carbon around but it's rarely a problem. If you're laying the bike up for winter, leave the plugs out and squirt some oil down both plug holes. Leave it in top gear and give the back wheel half a turn now and again. Most of the carbon will mix with the oil. Firing up next spring will remind you of those Redex days :-).It's certainly true, the best solution for a bike in daily use is a once a month high speed jaunt of 50 miles or more, that will certainly keep the engine fairly free of carbon.However, an engine with worn seals or damaged endplates will build up carbon regardless, simply because of inefficient combustion. Now and again, I've come across 'carbon seized' engines. This can happen over winter or occasionally overnight. The cause is a lump of carbon falling off a rotor and becoming wedged between rotor and housing. The solution is simple: Turn the engine backwards.Graham.

[johnbirchjar]

Thanks guys, I tend to run the old girl 12 months of the year anyway,and I don't class myself as a slow rider, so I dont think that I shall have any carbon problems,Re; the smearing of the end plates,are there any early warning signs to look out for? so that one can pull the engine appart and have them machined and re-mollied before they are beyond repair. (I have been led to believe that it is the left hand end plate that usualy smears,any idea why this is so?) Regards J.B.

[johnbirchjar]

a P.S. Some years back when I was new to the rotary scene,I had the "carbon wedging" problem,(that had me panicking I can tell you!) but a quick phone call to Dell Boy had me putting the bike in gear and pulling it backwards(like you said Graham) solved the problem,I'm off to see that nice Mr Cameron tomorrow,to relieve him of some of his Rotella 40,(I know that the Silkolene Comp-2 is supposed to be the best thing since the invention of the wheel,but it's still a bit pricy for this old pensioner) safe rotoring to all,J.B.

[gripper]

Hi Folks,I've just stripped my IP2 down with 35,000 miles on the clock. Richard has just moly'ed the plates for me after the RH side had smeared though the damage looked like the tip seals had picked up for about 1/4 of a revolution of the side plates. The transfer ports were covered with a good selection of carbon granules and a lot of these are now in the frame, (to be cleaned out before re-assembly) The end plates inside the lemon shaped port were pretty filthy as was the stationary gear and the main shaft bearings and the ing fins of the rotors. In fact all of the inside bits were not nice. I've estimated the engine rebuild will cost me about £1000 with new bearings, powder coating, moly'ing etc and thats me doing the rebuild. I will be changing to silkolene comp2 because hopefully it will reduce the build up of carbon and I wont have to do the engine again. Incidently, there is a web site devoted to Shell Rotella, with people raving about it, Americans of course. and none of them rotary orientated. worth a look but most of the references are for multigrade Rotella. yoursGripper

[johnbirchjar]

Hi Gripper,Your IP2 dos'nt appear to have done enough miles to have the engine in such a sorry state, are you sure the milage is genuine? unless of corse the bike has done mostly town work, which may (in my limited experiance)explain things. as an asside,can you tell me at what tempreture your bike ran at? I've asked elswhere on this forum for other air- cooled rotary owners to part with this information but they seem a bit reluctant.Regards, J.B.

[Dell Boy]

I had my 1st. air cooled in 1988. It was disposed of by the police at 4 years old/22,000 miles. The engine was smeared. Subsequent experience with it showed in those pre moly days & running on Rotella 40, 28,000 miles was about how far the engine would go. I did commute to London each day & ride around North & central London all day which did it no favours particularly on hot summer days. Meeting up with R.A.C. Interpol riding patrolmen showed they were suffering too & they had a big car battery to jump start members cars in the top box which could spin the rotary in fine style. I too installed a car battery in my top box otherwise with all the stopping & starting the standard battery would go flat. I was a past master at the 3 yard bump start in London traffic & was as fit as a butchers dog. Did anyone at Norton developments ever ride the early air cooleds in Birmingham say for a full day rather than round M.i.r.a. or the local roads. If they did what did they report back? Over to you Richard. Derek.

[Malc]

With reference to the eng running temperature on the air cooled bikes, I think 140 would be typical on a good engine. After the police bike was rebuilt (and before it was back in police trim), I wanted to run at 70 mph on the motorway but every time I ran to this speed the temp would rise to 170 degrees, drop the speed back down and the temp dropped back to about 150. After a couple of hundred miles it settled to 140. Another IP2 which I did a 500+ mile trip to Scotland many years ago used to run cooler at about 130 but when used on very cold days would stay just over 100.The factory used to say that 200 was time to switch off and allow to and 250 was meltdown!The 2 track bikes run about 150 to 180 but dont run very well below 140 so if kept waiting in the assembly area, the other riders did not appreciate the engine being kept running an chucking smoke out when keeping the temp up.To keep the battery charged on the police IP2s, the factory supplied 'on board battery chargers' which were bolted inside the pannier so while parked up at the stations, they could be plugged in and charged when not in use. This helped a bit but it was known that riders would wedge the throttle if at an incident to keep the engine at a very fast tick-over to keep the lights working. This often cooked the engine.

[Malc]

With reference to the amount of engine re-builds, Smearing was not a problem and none of the engines I have are molyd. There were other problems and if I were to put the anorak on and look at my service notes, there would be things like broken engine studs before they were changed from 6mm to 1/4 inch and sticking side seals and tight rotor bearings. This along with all the gearbox problems and again for a while, broken g/box mainshafts until they were modified.Four out of the five single rotor bikes were converted to twin rotor idle while in police use, these are easy to remember, YCH 107Y (Derby city) YCH 108Y (Alfreton) YCH 110Y (Matlock) and A631 CRB (Glossop) were all converted. Only AAU 244Y (Long Eaton) went for sale as a single rotor idle bike.As for Commanders, could not keep them on the road for constant smearing, one bike smeared several times. In the end, even though I was not supposed to be doing work that was under warranty, as the factory were busy molying the privately sold Commanders and F1's, the police bikes were lower priority so I would be given exchange plates by the factory to rebuild them and get them back on the road.The police driving school instructors Commander was given a Molyd engine early on for evaluation and I was told by the factory that I had to make up any excuse possible so that the bike went back to the factory before it went for sale. Well, it did have to go back for some reason! I saw the molyd engine when stripped while taking another bike back for warranty work the following week, perfect inside.There were exceptions though, with some bikes not smearing!

[Dell Boy]

YCH 110Y was the one I bought for £1,500.00 from some sort of dealer. The deal took place in a motorway services!! F736 FEA was my Ist. watercooled bought in `90/91. I ran that to just over 90,000 miles & never opened up the engine. It was never moly treated but from about 50,000 I used a lot of spark plugs to keep it starting. It was totally Knackered when I eventually took it off the road after a ex police Commander came along to replace it. I never got around to looking into it & sold it as being worn out. Derek.

[Malc]

I wondered where 110Y had got to. After spending 5 years maintaining each bike it is interesting to know what happens to them. This bike was ridden by a Seargant Stevenson who used to ride it very hard and eventually went on to instruct on driving school. This bike came in ringing and dinging just as it was wanted on royal visit duty.The 6mm eng studs had broken and were catching the back of the flywheel. This is when it got converted to twin rotor idle.I have seen 107Y for sale at Rugely a while back. 108Y is one I bought at the auction at the same time as A631.I went to buy 107Y but as it was the fist to go for sale it made silly money and it was ready for a complete overhaul.I waited and wanted to buy A631 but thought it may make too much as it had been fitted with the eng out of a later D reg bike and had the black covers. I bid on 108Y and got it but then bid on A631 and got that as well!Got home and the wife asked if I had got the one I went for, said, well yes but bought another as well! A631 is the red track bike.Sold 108Y to a chap in Aberdeen who came down on the train and rode it back. This did a big mileage travelling between Aberdeen and Portsmouth on a regular basis and never had any more engine work done, again putting paid to the theory that they all smear.He sold this on to another chap in Scotland and I think it is still up there. AAU 244Y is still around as seen at Rugely being serviced.

[johnbirchjar]

Hi Malc,Thanks for the info; on the eng;temps.I recall traveling round the M25 on the way to Portugal for the international rally of the N.O.C in 2006, and the weather being very hot,when the engine temp; went past 150c I begane to worry,so I pulled over on the hard shoulder and got on the phone to Graham, and he said much the same as the factory,stop at 200c and let the engine ,250 and it would be knackred!! I thought about it for a while, and seeing that we had only just started our journey and had many more miles to go I decided to raise the oil pump delivery a tad,theorising that a touch more oil in a very hot engine must help?or at least do no harm,anyway,the upshot was that by the time we reached Portugal the bike was very low on oil(even though I poured in the 1ltr that I carry on long journies)fortunatly Peter(him with the nice white Commander that (I think) lives in Yorkshire)allways carries cans of spare oil and sold me some.Needless to say I had by then re-set the pump back to the correct setting,and the bike seems none the worse for it.Who knows.

[Interpol2471]

I find some of this hard to follow as I have fitted a brand new thermocouple and temperature gauge to my bike because of this. I keep reading stories of high engine temperatures so I fitted everything new as my engine normally runs at about 100c, I have never had it go above 150c yet, thus I thought everything was under reading. At the toy run in Reading yesterday on the run there my bike averaged approx 100c on the A33 at about 80mph and then on the run which was all 1st and 2nd gear slow work thru the town the bike only went up to about 150c as said. When are people experiencing these really high temeratures as I cant My bike was moly coated at Shenstone and I run on Silkolene oil if these give any clues as to why I dont get the high temperatures, and I do use the bike quite regular in all conditions. The only other thing I have done is put cooling vents in the lower fairing and I found this also made quite a difference and you can feel the hot air being drawn out when on a run.CheersPaul

[Malc]

From what people have said, and it is quite logical, the molyd engines do run a bit cooler. I would think the extra ducts in the lower fairing panels on yours, Paul have also helped as you have said. The very high temps that the factory were concerned about were on the police bikes such as city of London and others when doing town work or herding footbal crowds. Also escort duty on wide loads on hot days. Mile after mile at walking pace and the rider just can't stop if the eng gets too hot. Plus, as said, wedging the throttle open at an incident to keep the battery charged to run the lights. The sorts of extremes made a good proving ground for the bikes. Even BMW used to acknowledge, that many faults found on police bikes would not generally appear on civillian models until three times the mileage. It was not just Norton that had problems, when the K series (8 valve) BMW's were replaced with the K1100 (16valve) models, 1 clutch failed at less than 20,000 miles and some had burnt valves at 40,000 miles and the first few were all sent back under warranty because they sounded like they were running on too lower octane fuel when under load. All problems were sorted eventually but this tainted their reliability compared to the older 8 valvers.

[Interpol2471]

Thanks Malc I shall worry no more I was worried on the toy run that the bike was getting up to 150c on the slow crawl thru the town waving at everyone watching the procession of biking Santa's but I guess 150c is not too hot then.

[wust588]

Yes, as I remember the air-cooled bikes had a reputation for running rather warm. In fact they were affectionately known as "mobile furnaces".I recall an Ip2 coming in from Notts police (I think) that was claimed to have reached near to 300C! It had run that hot that the air-box had melted. As can be imagined, the engine was shot, and the gear cluster was changed as a precaution. The old cluster was not thrown away though, I rescued it. I still have the scrap note! I often wonder that the air-cooled bike engines would have run a lot cooler ( aside from the benefits of reverse flow etc) without being powder coated.In fact I got the the powder coating chemically stripped off my air-cooled many years ago and it DOES work.Kind regards to everybody, John.