Classic engine temp,again!!

[johnbirchjar]

Hi guys,It's not a new toppic realy,just wondered if anyone could sugest why the engine temp on my Classic has progressivly got hotter as the miles have clocked up over the years,bearly reaching 90c when new,now mostly 140/150c,(irrispective of the weather) and as stated previously,a worrying 160,(52,000+ miles at the time of going to print,)in antisipation,J.B.

[Richard Negus]

John,You know the answer really.Almost time for an engine overhaul. It might just be sticking side or pin seals allowing hot gas down the sides of the rotors to mix with the rotor cooling air. Take the air transfer ports off and see what you find inside them.R.

[johnbirchjar]

What!! engine overhauls! after just a measly 52,000+ miles,(quick,a brandy to help ease the shock) I know of a number of Commanders with well over 90,000 miles on the clock and still going strong,(or is this one of the down sides of the air cooled bikes?)anyway,I shall take off the transfer ports and look for what? and will I need some sort of shoofty scope so I can look at the innards? a very glum J.B.

[Richard Negus]

John,I suggest taking off the left port first; wipe a clean finger inside the air passage of the left hand engine plate and study the result:a. if it is clean (but oily of course) then there's probably nothing amiss inside the engine so look for the problem elsewhere (air filter, carb settings, etc..)b. if there are a few specks of hard carbon in the oil, not a cause for concern.c. if the oil is dirty black, suspect stuck side seals and a sooner-rather-than-later engine strip to investigate. Not urgent, but it won't mend itself.d. if the finger has a greyish sludge, that is aluminium mixed with the oil and a sure sign that the end plates are being scored.Results a. and b. should be double-checked by looking at the right side too.If c. or d., then there's nothing extra to be learned by removing the right hand port. Although this was on an F1, it shows a typical dirty finger from the air passage.

050207-02.jpg

R.

[johnbirchjar]

Thanks for that Richard,I shall carry out the inspections soon and report back,ride safe,J.B.

[Mick Taylor]

For what it's worth John, my newly Moly'd Classic doesn't actually run completely cleanly until it's reached just over 100° although it's only done about 70 miles since the overhaul so that may well change.Riding it today, it was nice and warm out, about 17° and it was running just below 120° while I was on A roads.Going through town traffic it briefly crept up to 150°, cooled down quickly once I got going again and then later showed 150° while I was stuck in 1st gear behind a very slow moving lorry on a steep hill.Once we got going again it was straight back down to just below 120° and it seems very happy to me at this temperature although my Norton experience is near zero. Mick.

[johnbirchjar]

Thanks for that Mike,your bike runs more or less the same as mine exept the temp on mine dos'nt drop down again,(exept when I slow right down in traffic or poodling around in town) I went for a bit of a ride Saturday(about 40 miles,mostly duel-carigeway)and the temp didn't go over 150c once,just stayed at 145/148 on BOTH gauges don't know what the air temp was though,not cold, anyway,I shall pull bits off the old girl tomorrow and have a look-see,ride safe,J.B.

[Mick Taylor]

When I got my Classic, despite the very low mileage the distinctive 'chuffing' in the air box on idle was very evident even to my untrained ear. Richard advised removing the inlet ports to see if there were obvious carbon deposits. I didn't get very far, as soon as I loosened a few screws a dribble of jet black fluid came out and I took that as evidence enough.When Richard later stripped it down the outer side seals in each chamber were stuck...it seems the first owner had taken it too easy, probably allowed it to overheat too and it had caused carbon build up...everything else reflected the low miles.Now, with it's newly Moly'd engine it is a treat to ride.....have you listened to that air intake?Mick.

[johnbirchjar]

Hi Mike,I didn't think of listening for the "chuffing",next on my "to do" list?all else is failing.Looked inside the ports today Richard,left one not as black as the F1 in your picture,quite a bit of carbon though,right one not as much carbon and decidedly "less black",thankfuly no sign of the dreaded "grey sludge".I think the carbs are about right,end of the exhausts a sort of(matching) very pale brown.(they used to run almost white after a long fast run until I richened the mixture a tad)checked the air filter,seemed ok,oily damp? I am at a bit of a loss now,the only "glitch"I can think of is when starting from cold after being stood for a couple of days the old girl fires up instantly, but on one pot for about 3/4 seconds before the other one chimes in,instant fire up when hot/warm/cold,both pots,idles at 800revs,instant throtle pick-up,everything seems as it should be except the b****y engine temp!!most frustrating. Adding to my woes the voltage regulater I fitted in May has gone on the blink ,just over 2,000 miles (am I pleased I fitted a volt metre )this one from Electrex World,£66-80+p&p,went from charging at 13.5volts to 12.5,barely enough to charge the battery.E.W said to send it back and they would either send a replacment or refund me.anyone reccomend a good v/regulator?in antisipation,J.B.