New member and new owner

jsedacca · Oct 9, 2011

Hey guys,
I'm the proud new owner of a 75 Commando 850. It has around 10k on it, and is in great shape. The tank has been recently repainted, has a boyer ignition and a single Mikuni on it. I take delivery of it tomorrow and am curious as to what I should do to check everything over. I plan on changing the fluids (oil, gearbox, brake fluid) Any recommendations on oil, and gearbox oil? Any help is appreciated. Attached are some pics of the bike. Thanks guys and look forward to some advise.

DogT · Oct 9, 2011

Holy Cow, looks like a gud'un. Check everything you can and ride it. Welcome.

Dave
69S

jsedacca · Oct 9, 2011

DogT said:
Holy Cow, looks like a gud'un. Check everything you can and ride it. Welcome.

Dave
69S

Thanks for the welcome Dave. I'm looking forward to riding it after checking/changing all the fluids and performing a nut/bolt check on it. The seller is including a BUB 2-1 exhaust, stock Amal carbs, turn signals and all other factory parts he has. Any idea on how rare the BUB 2-1 system is?

DogT · Oct 9, 2011

Not my specialty, I'm sure someone will reply.

Dave
69S

bwolfie · Oct 9, 2011

Not all that rare.

MikeM · Oct 9, 2011

Welcome, nice bike. Lots of good information here.

MikeM

goo · Oct 9, 2011

new member also and looking for something similar.
if i may ask, about how much did yiu spend on it?
thanks,
ed

grandpaul · Oct 10, 2011

jsedacca said:
I'm the proud new owner of a 75 Commando 850... I plan on changing the fluids...

Welcome to the forum. The bike looks very nice! Was the previous owner not up to the maintenance schedule, or is it time to do the fluid change? The bike looks like a very clean regular rider. I like Castrol GTX motorcycle oil per the book, but you are likely to get at least 6 different suggestions on that subject.

Welcome to the ranks of Mark III ownership!

speirmoor · Oct 10, 2011

Snap!.Enjoy the Bike I'm sure you'll love it.

steveyacht · Oct 10, 2011

Greetings and Welcome! I am sure you will love it! Suggestions on oil are as varied and different as most personalities you will encounter. I went with the recommendation of the man who rebuilt my bike.

Changing all your fluids, to include the forks, are a good way to establish a baseline for future maintenance schedule. That way YOU know for sure where you are and when it is due next.

Hobot · Oct 10, 2011

Wow chromed tank and side cover highlights,cool. The only really dangerous thing to keep an eye on next 1000 miles is to check front brake fluid level at each gas stop to make sure there is no hidden leaks being blown away and missed till you have NO brake at all from one hard fine pull down to absolute terror no Brake the very next instant of need. The factory piston and puck in the brake are plain steel and rust up to foul seals. If you fill to full manual levels engine oil and primary and gear box you may find it spills out to its real innate levels with a mess until it does.

DO NOT over tighten primary chain when cold as tightens way up at road temps so keep an eye on that lesion to learn. Only takes one over tight event to tweak the whole drive train. We can only hope it didn't happen before you got it. Another more minor thing to check on is the cush drive cushions tend to get chewed up and the rear drum paddles get loose and twist so need weld and grind back to fix right a long time.

Only place you should put in more fluid than manual lists are the forks, aim for 175 ml per leg but not any more or hydro locks up after a 1/4 mile fine till air pocket pumps out, wheewhooee.

On yeah start shopping now for rear tire sales as C'do love to go though them in about 4000 miles even taking it easy on C'do torque glee. C'do's are tire and air balance sensitive, I like 2 lb less in front regardless of over all PSI inflation for the surface conditions. Harder the tires aired the smoother the isolactics isolate but then gets too harsh a ride on rough stuff.

Pull links out of rear sprocket valleys to see where they bare at speed to access chain wear state, chain tension has no effect on this. Sprocket teeth begin to wear down fast after links lift out ~1/3 valley depth.

Wellcome to the never ending attention and joys of Commandos.

Brooking 850 · Oct 10, 2011

welcome, make sure you keep the gearbox oil at its correct level , I use Redline shock proof gearbox oil, (blue in colour) and Penrite HPR 40 for the engine. (Penrite is out of Australia, you may find one with similar properties) Dont be scared to change your oil and oil filter often either.
Make sure there is no sludge in the oil tank, as they do produce a lbit !!!
There are many owners who who run different weight oil in the primary chaincase,( if it has belt drive that will not be necessary) I haven't done that mod as yet but am going to in the meantime I run the same as my engine oil, with no issues with stiction on the plates or slip.
Enjoy as I am
Regards Mike

Matt Spencer · Oct 10, 2011

Get yourself the ' C ' spanner and lean on the exhaust Rings after coming in from a ride , they take a few heat cyles , or a week of regular use before the copper O rings have settled in .
If fitting the 2-1 , copper cote or some graphite lube on the threads isnt a bad idea. Nobody should cross thead them , these days . use the fingers and give the pipes a wriggle tightening them with your hand
as far as possible , many turns .Before getting the spanner on the solid fin for the last few tuns .

Id have a bit of a yarn with the builder , to see where he's at with it . You dinnae wanna do more harm than good . Theses a list of LINKs at the top of the site , with a lot of usefull information .

Castrol used to do a ' CRI 40 monograde . petrol / diesel / turbo oil . Good stuff , but requires considerate use till warm . Was a std. oil for V-8 raceing , similar large internal componentry .
Oils for revvy little whizz bangs is seldom applicable .British stuffs generally , 30 wt. snow. 40 wt. normal . 50 wt, sahara , death valley etc .

Id assume it hasnt been thrashed , may need bedding in , generally 1/4 throttle , first 500 mile . retourque . 1/2 throttle to 1000. avoiding prolonged rpms steady , vary em a bit .Avoid past 3/4 throttle,
and Do Not sit throttle fully open , till past 2000 miles . Air Filtration is important . race bikes dont nessesarilly abide by this , but had been known to do a retourque @ ten miles , again at 50 , and be taken
for a quick spin to 500 to 1000 miles before raceing . Avoid heat soak or prolonged idleing, stationary . Traffic Lights and suberbia. Best to get out in the wildes for a familiariseation ride , when its cool .
Not in the recent heat wave weather .

If theres smoke coming of the ends of the footrests in the bends , shorten them .

KSUWildcatFan · Oct 12, 2011

Beautiful bike! Congrats!

jsedacca · Oct 12, 2011

grandpaul said:
jsedacca said:

I'm the proud new owner of a 75 Commando 850... I plan on changing the fluids...

Click to expand...

Welcome to the forum. The bike looks very nice! Was the previous owner not up to the maintenance schedule, or is it time to do the fluid change? The bike looks like a very clean regular rider. I like Castrol GTX motorcycle oil per the book, but you are likely to get at least 6 different suggestions on that subject.

Welcome to the ranks of Mark III ownership!

The previous owner had the bike for 10 years and put on approximately 500 miles. Figure a changing of the fluids is a good idea since it has been sitting, and I get a baseline for the scheduled maintenance. Thanks for the recommendation on the oil as well!

jsedacca · Oct 12, 2011

hobot said:
Wow chromed tank and side cover highlights,cool. The only really dangerous thing to keep an eye on next 1000 miles is to check front brake fluid level at each gas stop to make sure there is no hidden leaks being blown away and missed till you have NO brake at all from one hard fine pull down to absolute terror no Brake the very next instant of need. The factory piston and puck in the brake are plain steel and rust up to foul seals. If you fill to full manual levels engine oil and primary and gear box you may find it spills out to its real innate levels with a mess until it does.

DO NOT over tighten primary chain when cold as tightens way up at road temps so keep an eye on that lesion to learn. Only takes one over tight event to tweak the whole drive train. We can only hope it didn't happen before you got it. Another more minor thing to check on is the cush drive cushions tend to get chewed up and the rear drum paddles get loose and twist so need weld and grind back to fix right a long time.

Only place you should put in more fluid than manual lists are the forks, aim for 175 ml per leg but not any more or hydro locks up after a 1/4 mile fine till air pocket pumps out, wheewhooee.

On yeah start shopping now for rear tire sales as C'do love to go though them in about 4000 miles even taking it easy on C'do torque glee. C'do's are tire and air balance sensitive, I like 2 lb less in front regardless of over all PSI inflation for the surface conditions. Harder the tires aired the smoother the isolactics isolate but then gets too harsh a ride on rough stuff.

Pull links out of rear sprocket valleys to see where they bare at speed to access chain wear state, chain tension has no effect on this. Sprocket teeth begin to wear down fast after links lift out ~1/3 valley depth.

Wellcome to the never ending attention and joys of Commandos.

Appreciate all the plethora of information. I noticed finding neutral is kind of tough and figure the primary chain needs some adjusting. I'll pop the cover off and check the chain and get that squared away along with adjusting/lubing the clutch cable. The brakes feel fine but will flush them with fresh fluid. New tires are definitely a must. The current ones have some dry rot and don't want to tempt fate. Thanks for all the help. It is greatly appreciated.

Hobot · Oct 12, 2011

Forgetabout the tires for now, just don't play racer in the rain or try stoppies is all, so apply your time/money on getting more vitals under control, by then you will be ready and able to use the smoother higher traction of new tyres. I'm been at Norton daily for 12+ yrs and still learn daily what I've missed out on, ugh, or must repair in learning curve balls. C'do even mildly ridden go thru rear tires in ~4000 miles, barely a month of average good time riding.

dynodave · Oct 12, 2011

jsedacca
MKIII?
Seems like all or most of the advice came from owners that DO NOT own a MKIII Electric start.
Clutch problem is typical of non sorted MKIII clutch which requires different treatment from 68-74 commando.
Old analog boyer on MKIII... very bad....another problem to be examined/sorted before reliability is assured and you cause expensive damage.
Has this bike gotten a new cam. MKIII are extrememly notorious for bad soft cams. A high percentage died by 10K, very few went 20K. Some, but not many, went longer.
With Electric start the higher 180W alternator is marginally adequate, it will probably not keep the battery up if you run in a headlight state.
I like the MKIII a lot (I've got 3) but they need to be sorted out to make them trouble free. Which begs the question why did the previous owner drive it only 500 miles?

swooshdave · Oct 12, 2011

dynodave said:
jsedacca
I like the MKIII a lot (I've got 3) but they need to be sorted out to make them trouble free. Which begs the question why did the previous owner drive it only 500 miles?

Not everyone who has bikes has a lot of time to ride them. I wouldn't automatically assume the bike has issues.

jsedacca · Oct 12, 2011

dynodave said:
jsedacca
MKIII?
Seems like all or most of the advice came from owners that DO NOT own a MKIII Electric start.
Clutch problem is typical of non sorted MKIII clutch which requires different treatment from 68-74 commando.
Old analog boyer on MKIII... very bad....another problem to be examined/sorted before reliability is assured and you cause expensive damage.
Has this bike gotten a new cam. MKIII are extrememly notorious for bad soft cams. A high percentage died by 10K, very few went 20K. Some, but not many, went longer.
With Electric start the higher 180W alternator is marginally adequate, it will probably not keep the battery up if you run in a headlight state.
I like the MKIII a lot (I've got 3) but they need to be sorted out to make them trouble free. Which begs the question why did the previous owner drive it only 500 miles?

Care to share the fix for the clutch? Like I said, any help would be appreciated. I downloaded the commando repair manual off the internet and have one coming in the mail for good measure. I've heard bad things about the old Boyer ignitions and will eventually switch to a tri-spark once all the maintenance is complete.

New member and new owner

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