The Combat Question

Thought I'd bring this Combat issue up again since it's something that regularly gnaws at the back of my brain and haunts me at irregular intervals, (until I'm forced to think of my old girlfriend Andrea's hooters... her only good quality... long enough to make it go away). My bike is a 72 Combat that was built in April of that year, with serial number 206,267. I know as far as Combat's go, the later the better, and it appears to me that mine is kind of borderline as to whether it should be considered early or later. Was wondering if anyone can tell me where my bike stands as far as changes in the case etc. from the early hand grenades, and if in fact mine falls into that portable explosive device category. I read a thread on here where someone mentioned that they had purchased a 72 Combat brand new, and opened it up to find it already had superblends in it from the factory. Anyone have any idea when they might have started doing that?

A couple things in my favor, the jugs were painted black when I got it, which I've heard may indicate that it's been rebuilt or at least taken apart? Also the bike's got about 12K on it, which I'm also told it wouldn't have made it that far without having the factory recall done on it. The PO said the bike was running before it was put away a decade and a half ago... but he got that knowledge 2nd hand, having bought the bike from the original owner, who is the last one to have ridden it. As far as the bike's status right now, it starts and runs pretty rough at high RPM, like over 3500 or so. I'm waiting for new plug wires to come in the mail before I finish timing it and balance out the carbs... but it runs strong and usually starts on the first kick... feeling positive so far that I've got a good motor. Also, I'm looking for any special operating practices that might pertain specifically to the Combat. Just looking for some food for thought.

As far as the case go, if yours has the mag face casted over than you probable have the later reinforced cases. If you have a cover over your mag boss then they might be the older type with the motor mountings machined too deep. This is not absolute and you should check your cases for these faults by scrolling down a page or two at Dyno Dave's site, below, to see what I am talking about. If you have the mag boss casted over then you may have the improved set.

http://atlanticgreen.com/engcases.htm

Bearings on the other had are a little harder to validate. If you have some rumbling and grumbling in these areas you may want to take it down to see what you have. This of course would beg for new anyhow.

My old cases with the cover over the mag boss, had a roller in the drive side and a ball in the timing side. This is normal and can be considered a viable option on rebuild. I put sd's in both sides of my newer 210xxx cases. These are the newer reinforced cases

I believe all Combats had black cylinders and is one of the indicators of a Combat, although, again, not absolute.

Robb2014 said:

Also the bike's got about 12K on it, which I'm also told it wouldn't have made it that far without having the factory recall done on it.

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This.

Ms Peel is a March issue Combat in 203### range and if yours make it past 10-12K miles then its been gone through enough to trust it from just blowing up from original factor over sigths. Both of my Combats came with high mileage on original non superblend rollers in such good condition - only wanting to start all new required replacing. Main issue of Combat is the mess they make if run into the 2S cam wake up range and then some for a while, wet sumps but don't phase em other wise but sure does surprise the hot shots sport bike if you are willing to be as hard harted as real racers and don't mind rebuilding tranny more often than engine. OldBrit site has mods to oil sump re-location but I didn't bother on my current all factory Combat and just have my way with her now and then and clean up the road sex mess afterwards while still in after glow.... I'd limit to 7200 is not upgrading the valve train or tends to float just as ya expect to zing around the semi pass in time in lower gear.

I have a later one, 208946, I was told by the PO that the warranty work and bearings were done by TC Christianson at sunset motors,
When I rebuilt it I found ball bearings on both sides, .040 over slotted pistons and a host of other scary things.

Don't trust anything, open it up for yourself and put it together right. A few dollars now will save problems in the future.

I feel a Combat is cool to have, the factory hot rod. And will live if properly taken care of. I just finished the overhaul of mine this fall,
and after 8.6 miles i'm hooked. I rode it 1 mile after I woke it from it's 25 year slumber. I was amazed at how quick it was.

I bought a Combat nearly 2 years ago and mulled over the decision for some time......add to this I bought it sight unseen.....from the other end of the country....
Flew down and rode it back, mechanically it runs fine, easy starter and goes like the clappers.
The motor number is 208600, 32 mm carbs, C on the head and get to 5000 rpm and the tone changes to a growl and it wants to go faster...... in my head I visualise all those 40 year old parts flailing around so never go much past 5000 rpm.....I used to worry.......
I would like to know the full story though, heard things like they found the valves touched the pistons, backed off the tappets and out the door they went..... the ports are hogged out too much and its really just the cam/carbs/comp that make the difference.
For me its a keeper like the Ducati Darmah with its equally notorious crank/desmo/electrics stories.....I used to worry about that too........ but after owning it for 25 years it still seems fine. Love this forum its awesome.

I have a later one too, 208018. Found in a drafty Ottawa garage after a 25 yr. slumber. 10,000 Kms. Named her Crazy Combat. Replaced the T.S. ball and D.S. roller, with superblends first thing. Noticed the brass camshaft retaining washer had the bendover- tab cracks so fit 828 cc. type bushings to avoid problems. Detuned her with a standard cam which I now regret as that mean- nasty sound is gone... future reversion project. She attracts comments all the time .

All '72 cases are the re informed type with breather at the base of the left side. Mine is an early example 201xxx with 52,000 miles and of course all the upgrades. if properly build, the combat threat is only a myth. Shame on those that detune a combat.

Arredgedly , first COMBATS had valve tangle . dimensional issues re Lift/guides , pushrod length & IT WASNT just the combats that shat main bearings .

ANY Combat was Black Barreled , that was the Identity wotsit .

Full Whellie , full rpm , try a fast hard cearchange . You may sense the clutch assy trying to bounce around . The Hows it Ridden , came into it .
The odd one was thrashed mercilously . The odd one was riden hard/ flat; as in till it ran ovewr the top of the powerband . This isnt at 7.000 rpm . :?

like any well oiled piece of well adjusted machineary , it will run like a swiss watch . or the Flying scotsman .Or suchlike . If the school boys havnt been at it .

My ' favourite ' is the W&S Valve springs and BSA 30 degree advance unit .

The issues were all resolved by October ? ? ? leaveing only mongrel riders & maintanance as issues .
As the spec was generally in advance of the early P R Commandos , I presume they ( Norton ) dropped it
to avoid numbskulls overreving , bounceing of cars , and knocking over streetlamps . As anyone can ride like Barry Sheene , with a little practice . :shock:

Matt Spencer said:

Arredgedly , first COMBATS had valve tangle . dimensional issues re Lift/guides , pushrod length & IT WASNT just the combats that shat main bearings .

ANY Combat was Black Barreled , that was the Identity wotsit .

Full Whellie , full rpm , try a fast hard cearchange . You may sense the clutch assy trying to bounce around . The Hows it Ridden , came into it .
The odd one was thrashed mercilously . The odd one was riden hard/ flat; as in till it ran ovewr the top of the powerband . This isnt at 7.000 rpm . :?

like any well oiled piece of well adjusted machineary , it will run like a swiss watch . or the Flying scotsman .Or suchlike . If the school boys havnt been at it .

My ' favourite ' is the W&S Valve springs and BSA 30 degree advance unit .

The issues were all resolved by October ? ? ? leaveing only mongrel riders & maintanance as issues .
As the spec was generally in advance of the early P R Commandos , I presume they ( Norton ) dropped it
to avoid numbskulls overreving , bounceing of cars , and knocking over streetlamps . As anyone can ride like Barry Sheene , with a little practice . :shock:

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Don't know about you, but my experience with an early combat is the one I bought new 201123. It ran the wheels off any other machine I encountered and at 5000 miles when I sold it had no problems that a tune up at Bill's Motorcycles in San Bernadino didn't fix. The auto advance unit needed to be replaced with a '73 unit.

I've owned mine from new & it's in the 203XXX range. It had pretty much all the combat problems. If yours has done 12K miles I'd say the main bearings have been changed as my originals only lasted £4K miles. If they haven't been changed, the worse that will happen is that it will start making a rumbling sound. It will still ride ok & get you home without drama.
The thing that you really need to be sure of is that it doesn't still have the slotted pistons fitted. I can't remember when the top came off mine but it was out of warranty & I was stuck with a damaged engine a long way from home. If you just want to be sure about pistons (& please do be sure), you could take off the head & barrels as one unit to get access to the pistons. A lot less dismantling that way. While you have the barrels off have a look at the cam as they wear too.
Enjoy riding it. They are a great ride.

Ian

Got to get rid of them Combat tab camshaft 'thrust' washers. Pre-Peel processed her's thought the oil pump. There were a handful of bad design and production errors at the very begining so average blow up mileage was 4000 miles. The sloppy ignition was the main issue, then the bearings etc. There's a forum post that has a 2 page detailed blow by blow disection-history of how The Combat blew Norton down. It wasn't the final straw but blew reserves so bad they never really recovered.
My Trixie Combat is 210xxx range a Sept '72 IIRC. She ran great after years of storage so just decided to baby her till something needed attending to... a seizure-fracture of .040+ comma oil slot pistons rubbing on a smooshed into bore Al head gasket comedy of Norton good idea errors. Ya pays ya's money and takes ya's chances on just riding off into the sun set but shoot just putting rump in the saddle is risking life and limbs and bike, so just see what happens till the soup to nuts mood strikes or more sudden show stopper.

I don't understand the bad opinion of Combat's 2S cam, especially that it lacks some low end grunt, pashaw as even this post's initiator says 5000 is growling enough, my research reveals a sense of a 3rd piston kicking in as fast swing tach needle crosses 6800 and as Matt says 7000 aint nearly the end of its rising pull. It was the Combat that brought the disc brake to market and the Go Farther Faster poster of Interstate version so to me its the Cream of the Commando Crop. I can attest that if the elite hi horse power balloon tire squadrons are limiting their top speed to 120, which vast majority do, then a Combat using all its got will not be delaying the pack nor left out of sight, must to the displeasure of said superior non Commando road appliances. If you wring the neck out of 1st and 2nd its not uncommon to float the front. A Commando is harder to wheelie than a modern sports bike so can actually accelerate harder in the tights than the newbie on the block.
Not for long mind you as that's what horse provides but torque is King when handling real turns is involved, way over get a ticket speeds too. BUT un-tammed Commando's can kill you entering turns that get a big rougher after apex so creep up on THE Hinge, best done with low air tire practice and never ever forget that sense of Hinge onset or guess what goes Boom.
I like 20T ratio in factory Combat tune.

I have not thoroughly read the posts here so may just be echoing somebody else. But before you freak out about your motor you should ask yourself how you plan to ride it. Are you going to cruise around at 3000 RPMs with an occasional push above it, or are you most likely to see sustained high RPMs at 5000 or above?

Take cap off the oil tank and rev up the bike while watching the return flow of oil. Most likely there will be a point at which you stop getting oil back to the tank. Say 4500 RPMs or so. That is the line you don't want to cross for sustained riding. If the bike has never been ridden much in that zone it is very possible for it to have lasted 12,000 miles without blowing up. Although I have to agree with Bwolfie that you will never know what is insidethe motor until you look. Personally I would be more comfortable knowing nobody had been inside the motor than wondering what some idiot might have done ahead of me during the first 40 years of its life.

Russ

By 'sustained' do you mean maintaining those revs for extended periods -high speed cruise-wise, or just regular full powerband rev-range usage through the gears?
I find it appalling to read that some would own/cherish/covet a Combat yet not ride it in the manner most rewarding as a period visceral muscle-bike, surely an Enfield [dum-dum] Bullet would suit those not wanting to really feel that eager camming bite/growling aural urgency/adrenaline surge signal of a true Combat, or would that spoil the pose of [basking in reflected historical macho aura] pseudo glory-boy types?

O.K., like that super-radical high lift cam goes back in . Original pistons so will check for those slots too. If so will be saving for JS rods-pistons. Can't say when ,as we are saving for the big Thailand -Myanmar trip.

My first Combat was bone stock and famous for being the shop demo sales bike that sold to hot roder that didn't baby it but conitnued its fame for staying on it a lot. I've run in factory state at 5000 rpm 20 T sprocket keeping up with turnpike traffic a couple of hours a leg. They just get wet sumped enough to blow oil out but various breather devices handle the bulk of that. i've had long discussions with the UK crowd and others to be told Commando's can do 5000 rpm all day long no problemo. Combats are easy as reliable as any other model for same reasons and easy corrections. Another thing the wise old ones conveyed was Combats mainly wear trying to lug em so keep em spun up within reason for longest wearing. Its does take a while to get past all the noise and commotion runing in top over 6000 but its not hurting them compared to short shifting all the time.

hobot said:

My first Combat was bone stock and famous for being the shop demo sales bike that sold to hot roder that didn't baby it but conitnued its fame for staying on it a lot. I've run in factory state at 5000 rpm 20 T sprocket keeping up with turnpike traffic a couple of hours a leg. They just get wet sumped enough to blow oil out but various breather devices handle the bulk of that. i've had long discussions with the UK crowd and others to be told Commando's can do 5000 rpm all day long no problemo. Combats are easy as reliable as any other model for same reasons and easy corrections. Another thing the wise old ones conveyed was Combats mainly wear trying to lug em so keep em spun up within reason for longest wearing. Its does take a while to get past all the noise and commotion runing in top over 6000 but its not hurting them compared to short shifting all the time.

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spoken like a combat owner, I agree.

I stand corrected on my earlier position. Apparently the Combat motor's oil return problem is a myth that I have fallen for. Another example of a solution to a problem that doesn't exist. I have to admit that I have watched my oil tank while running up the throttle and witnessed that fact that oil stopped returning to the tank at high RPMs. I mistook this as confirmation of the mythical oil starvation. That's the problem with the internet. You just can't believe anything you read.

Russ

Is the problem described as oil 'starvation' actually a scavenging issue? Or a non-return to the [dry] sump/top end retention/internal air pressure pumping/breathing matter?

Duh Dudes... the Combat breather returns way more oil to tank in wet sumped conditions than wimpy gear pump pushes back, so on wet sumped starts there should be a pencil thick breath jet until 1/2 min later its pumped below breather return and just the oil pump air/oil spittle comes out spread against the tank walls by the baffled exit. At speed the breather return also returns oil the uncovered front drain can't. There is no disaster lurking to run the oily snot out of factory Combats but the mess to wipe up and check oil during or after a day or weekend long Combat 2S neck wringing G force glee. Ms Peel with the oil pick up moved to rear and Krank PCV inline was oil tight and clean to whit glove test inside the big breather tube of TS case. I swear and promise not to kick up heels on each mild ride but dang it just when ya think whoa that's enough that 3rd piston starts to kick in so its so easy to use up last rpms so fast I can't resist and just mop up the road sex evidence later.