cooling probs.

[johnbirchjar]

Hi guys,here is a problem some of the more knowledgable amongst you may have the answere to.Just over four thousand miles ago my Classic had a COMPLEAT engine re-build,everything was renewed exept the crankshaft.At first the engine ran a tad warm(150'C')on local roads in Darbyshire,OK, things are a bit tight,it will run cooler after a few hundred miles,no such luck , The miles clocked up and it ran no cooler.On the way to Cadwell on Wednesday,(The first long journey since the re-build) riding into a strong head wind on the M11 I increased the speed to 75/80mph and within a couple of miles the temp rose to 175/180'C' so I slowed down to 65/70.Off the A1M at Peterborogh and the temp drops down to 160'C' and stays at this all the way to Cadwell(no M ways or duel c/ways)A blast round Cadwell on the Thursday,temp stays at 150.On the way home all is well untill I get on the A1M at Peterborogh,(I now have a following wind) speed up to 75/80mph and within 3to4 miles the temp is up to 190'C'!! I have to slow down to 60mph to get the temp down to 160'C' I had to stay at this speed all the way to Stanstead.(as you can immagine, 60mph on a motorway is well scary ) I tried several times to increase the speed to 70 but the temp shot up immidiatly.once I came off the motorway the temp droped within the first mile,and by now it was well into late evening(19-30hrs?)so the temp stayed at 160.On the A130 (a fast d/caridgway between Chelmsford and my humble abode)I cranked the speed up to 75/80(my normal speed on this stretch of road) and the temp stayed at 160,(the time is now 20-30ish and quite )So unless someone comes up with a cure for the over- heating I will have to stay off M/ways or only ride the Classic at night ,rgds,J.B.

[fogrider]

Basics, either too much heat being produced, or insufficient cooling, or both. So, mixture too weak, ignition too retarded or too advanced, brakes binding ?, all will create extra heat. Cooling; poor airflow over the fins caused by changes to mudguard/fork shape,added horns or lights for instance. Even low tyre pressures can add to the heat generated. Even the carbs not perfectly balanced can go towards heat generated. Spark plugs too hot in the heat range.? Even all these little things put together. Just a few items to check. Better than having to slow down !

[gripper]

Does the bike feel like it is running hotter than it did before the rebuild? i.e. is there noticeably more heat coming off the engine? The temperature sensor may be faulty or the gauge. There are old threads on here about other temperature measuring methods. Did you have the engine powder coating renewed when it was rebuilt?

[johnbirchjar]

Hi Fogrider,in answer to your sugestions,fuel mixture looks about right,(exhausts that nice sort of light brown/greyish colour) and both the same.Same plugs that I have allways used for the past 50+thousand miles.Spoke to Boyers about the posability that the timing of the ignition box being"off" and they reconed that it was "highly unlikely" allmost akin to "winning the Lottery" ,No binding brakes,and I tend to keep an eye on the tyre preshers, Interupted air flow?Well I do have the fairing from the Triumph 900 Tripple on the bike,but that has been on since 2006 and didn't make any differance to the running temp before, I did run the bike "naked" for about 5/600 hundred miles after the engine rebuild,didn't seem to make any differance,the bike still ran b****y hot I thought the temp might drop as the miles progressed,but it hasn't,and as stated previously,the first journey of any distance on fast roads and the temp was way up in the high hundreds,thanks for your input,rgds,J.B.

[johnbirchjar]

Hi Gripper,The reason for the rebuild was the build up of carbon restricting airflow,and it ran pretty hot(175/180c)compleat engine rebuild and it's no better, infact the engine seams to get hotter quicker, It dosn't feel like it's running hot and seems to run fine, so today I fitted an electronic temp guage to check the accuarasy of the one on the bike,the original one fitted to the bike is spot on,so the problem remains,and what to do about it? ,J.B.

[johnbirchjar]

ps,and no the engine wasn't re-powder coated,

[kanonkopdrinker]

What plugs are you using John?Is it the C9Es? Or the 'hotter' C8Es?Most watercooled Nortons will use the '8's - while the hotter running air-cooled seem to prefer the '9's.Just a thought ....DC

[wust588]

What is your oil consumption like? Perhaps a bit lean?I've always felt that the air, the air cooled engines take in is somewhat restricted by the closeness of the coil cover, and coils,and two thick filters.I binned one of my filters years ago, and also removed the powder coating from both housings.

[johnbirchjar]

Hi Wus,oil consumption?300 miles to the pint(same as the old engine) one of the first things I tried was to dump one of the air filters,made no differance.While on the subject of oil consumption,I was having a chat to Tony Page,(him with the IP2 that has covered allmost 500,000 miles)and asked him how many engine re-builds his bike has had in all those miles? ONLY TWO!!! his bikes oil consumption?500 miles to the pint!! and he reconed that the reason my bike was so carboned up after only 57,000 miles was that the bike was using way to much oil,(but this would not make the bike run hot,) so this is not the problem,back to the drawing board ,rgds,J.B.

[johnbirchjar]

HI Dave,Iv'e allways used the 8s,and never had a cooling problem in 47,000+miles on the old engine before she carboned up,(may try the 9s as I am getting pretty desperate and clutching at straws )rgds,J.B,

[wust588]

John,I'm sorry you are still having trouble.When you say you checked your temperature gauge by using a different type, where did you pick up the value from? Were you using the original sender wire?Bear in mind these engines have always run very hot, as have the water cooled bikes. Have you felt excessive heat coming off the engine?I've often wondered if the air cooled temperature wire positioned where it is, reflects a true engine running temperature.Just a few thoughts.John.

[johnbirchjar]

Hi John,the pick up point on the "other" temp guage was from the spark plug,(the "sender" is a copper ring that re-places the ring on the spark plug and is screwed back in place)now how accurate this is I know not ,and you are not the first person to think that perhaps Norton's should have located there sender some where else?Thinking about "Heat comming off the engine" strange that,not noticably so!!Now theres a thought .I wonder if BOTH temp guages are wrong ?A means of checking this would be if any of our readers has in there possesion one of those "Ray Gun" type thingies that one points at the engine and gets a temp: reading,(or what they are called so I can sorce one)I await a response,rgds,J.B.

[Joe]

Hello JB, I have one of those Infrared non contact thermometers and could call round Monday afternoon to assist you if you like. In an ideal world I should probably bring my Classic for comparasion but I don't think I'll have time to get it out from the back of the garage by then, too many things to do. Regards, Joe.

[johnbirchjar]

Hi Joe,Monday afternoon would be great .How do's 14-00hrs sound?rgds,J.B.

[Joe]

Hello JB, Sounds good to me. I've got your number, I'll give you a ring in the morning. Regards, Joe.

[johnbirchjar]

Hi Joe,If you can phone between 09-30 &10-30 that would be ideal,(only I have a bit of running around to do before meeting you in the PM.)I know it's a bit of a cheek ,but do you have a 7mm box spanner I could borrow?I have nothing that small and neither do any of my biker buddies,(I have a new Thurmo Coupling to re-place the old one if it is on the blink)See you tomorrow,ride safe,J.B.

[johnbirchjar]

Hi guys,panic over, using Joe's magic "ray gun" revealed that the temp guage on the bike was reading 30c fast!!(so 160 was really 130)which made me a very happy biker .I will fit the new Thermo Coupling and report anon,ride safe,J.B.