Combat fixes

There was a Combat for sale at a swap meet a couple of years ago, good price, think it was around 5K for a cosmetically nice looking bike. I was aware that there are fixes for the Combat but the owner did not know much at all about internal condition or changes made to the motor, nor did I really know what the fixes involve, so I passed on it.

What exactly are the changes needed to make these engines good for longhaul riding, here I mean 400 - 500 mile days sometimes two up with luggage?
Or is it a pipe dream to use the bike in that way?

The change to Superblends seems to be the main change, but what about dropping compression and changing cams?

Anything else?

thanks
Glen

some of the changes I make to make more workable with today's fuel's ( USA ) is to shave .030 off the piston tops to drop the compression a little and still use the 2S cam. If you want less camshaft than you will need to drop the compression even more. I DONT like the plate's that some recommend as it is already a week joint, instead I would find a low comp head and go from there. the next mod is the oil pickup and NOT THE OLD BRITTS way by butchering the case's. from there the rest is like any other Norton. Breather mod, tach drive seal, head studs fixed and the list can go on. A great start is the INOA tech digest ( wrong on the combat oil pickup ) but has a lot of info.

Quite frankly, the more pure you keep it the close to a pipe dream it is.

You can make these reliable. Ignition system, charging system upgrades, a good single carb conversion, Oring chain (debatable), sealed bearing in the wheels......I could go on, but these are all things that improve on dependability.

As far as the cam and compression go, a .030 to .040 plate under the jug and a standard cam will definitely smooth things for the long haul. There are cams that improve on the standard cam, but really, the standard cam is truly proven to run well. That being said, the after market cam can be super tough.

I have the JS stage 1 with BSA lifter kit. This produces performance AND reliability. If you go this way you may want to leave the compression plate out of the equation or maybe go to a .020 plate. Also, tuning for for this cam setup will be difficult with a single carb. It like to GO.

Quite frankly, the more pure you keep it the close to a pipe dream it is.

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Amend to that wisdom I agree with w/o going nutzo away form basic Norton Commando as Combats are the peak and cream of the whole crop and more of em make and sold than any other plus put the long range ease ability of Cdo's on the cross continent map.

I run factory Combat all year now on 87-91 octane boozed and no boozed gas no issue at all on sanely non race like throttle use up to the easy ton on 19T, just to stay ordinary set up, though 20T is better for real life ease and pull w/o detonation.

Lowering compression shoots 2S cam in foot and Combats are famous to ping/knock when sticking a 1S cam in 10:1 CR. As rpm builds there's less tendency to go bang but do have to dial in timing just so creeping up on it as may run better a big advanced with the newer faster learn burn gasoline but is leaner to begin with so may have to diddle floats to needle to richen up over factory settings.

Early head steady plates tend to fatigue crack and often the swingarm gets
switched for more braced 850 type and adjustabe iso's. Easy standard fix ups.
Oil return only matter on long held throttle that keep blood in head and oil in case pushed to the rear off drain sump so oil shows up running Combats in their on cam power band. Breather help this but Combat have secondary higher flow oil return path in the breather hose so no big deal but the mess afer embrassing sports bike up to the ton. If hard hearted enough to whip Combat to maximum.

hobot

"Anything else" would have to include the bronze washer with the stoopid bend over tabs that are to fit into a hole in the timing side case camshaft end and the tab that is to fit into the hole usually has a micro-crack in it so it may or may not fall apart and get slurped into the oil pump and destroy your motor lickety split. Whew !. Fit the 828 c.c. timing side cambush as a fix and ream to fit the O.D. of whatever cam you decide on using . Whew!

And the pistons. If it still has the original "break away" Hepolite pistons those should be replaced.

The Combats come into power at high RPM, for this reason they also were equipped with 19-tooth drive sprokets. I "assume" (since I don't know for a fact) that this was to make it easier to keep the bike in the power band. Mine pumps return oil just fine to about 4500 RPM but after that it starts to collect in the case. This is not a big issue in my local riding but if I were going to be doing a lot of highway miles and had NOT changed the oil pick-up in the crank case, I would be going to a bigger drive sprocket so that I could keep the cruising RPM lower.

I don't know how the bike would feel set up this way riding two up. My feeling is that if you are going to lower the compression and change the cam, you might as well just shop for an 850 to begin with. Otherwise why have a Combat motor?

Russ

Just modernize it like has been mentioned but don't de-tune it.

I bought a new Combat Commando in Vancouver in 72 in around May of that year. After a gentle break in I drove it like an absolute maniac, shifting at red line often. I took it on back road fishing trips to the Coquihalla Lakes before the hiway was put in and it was just rough logging roads with 20' streams crossing it (I'm talkin real Hobot stuff here). I had fishing and camping gear and grub for a week strapped on the Norton. I rode it to Prince George, Kamloops at different times and when I was in Prince George I rode it to Houston, Peace River over the pine pass to the Alta. border and other such trips. I fried the top end coming back from Kamloops one time when the oil tank drain plug loosened and was only held in place by the outer cover. Since all you do is pass cars at high speed through the Fraser Canyon I didn't notice it till it was too late. Motor didn't seize but it scored the cylinders, pistons rings and had to haul the bike home. When I tore the engine down I found it had superblends already in it. So the Combats in western Canada already had superblends by that time.

2 up with luggage is another thing. I always found the Commando lacking for caring payloads. My big beautiful black and bouncy babe used to bottom out the Norton on just an average bump. Together we weighed in around 325 lbs or so. The thing I envied about Harley riders was their ability to pack a big mama on the back and why (I like to think) said babe left me for a harley rider. The Norton still hauled ass no problem but the bumps were the killer for 2 up riding I found anyway. Yet I've heard accounts of others doing long trips 2 up on Commandos so maybe others can share their experiences.

The several 750's I've had since were combats and I wouldn't try to de-tune them for any reason. You can always ride them like a pre-combat if you so choose.

No need to upgrade to 850 cam bush, just break off the thrust washer tabs, ugh if not missing already processed though engine and oil pump, file even and stick back in on TS as that's the side the cam is drawn to by the tack drive.

A Combat likes 20T better than 19T as allows freeway cruise 80 mph 4000 rpm and ups 2nd gear zone into the 80's too near redline power band front lifting passing gear on rising 2S torque curve. Main thing a Combat needs is a rev limiter.

I've had my Combat since new and would ignore some of the above. Superblends - probably already have been replaced. Electronic ignition - to replace the sticky AA unit. Nothing against points - it is the AA unit that sucks. I went to a Pazon Altair but used a Boyer Analog for 35 years before that and it was fine. The Altair is much better though. A link rod headsteady on any Norton Commando to me is a must for safety. Other than that just ride it. You will be diddling with the Amals but no big deal and a single carb on a Combat is just wrong. Leave compression as is please. Mine runs on piss lawnmower gas just fine if I have to but normally I just use premium.

Actually even superblends not needed if the Combat not lugger nor over rev'd their flat roller on one side and ball on the other last and last decades and still be about pristine. Its risk taking not to know if the oil slot pistons still inside and there was a period around Combats that Norton came up with Al gasket which is TABOO and I found out the hard hard way why, as didn't look in deep as my 2nd Combat ran great after decade stored - for 3 wks then total engine rebuild resulted w/o ever being hard on throttle just blew up at level legal 55 mph.

First Combats were so bad d/t factory over sights and mistake none lasted but 4-5000 miles till break down so any that exist past the point have basic survival upgrades done already in ignition AAU and case machining and bearings.

I've only been into Commandos for a year....had all the books and mags for over 20 but never the bike. I bought a Combat off our local auction site, flew down to get it and rode it 800 kms home. I've done about 3000 miles on it so far and its great. Love it when it comes on cam. Bike had been restored at some point but the history is pretty vague.
Electronic ignition and Tri Spark voltage regulator make this an easy to live with machine.
Posing at a recent Vintage Run here in Auckland :roll:

Hey RennieK ,Hobot not be the only wildlife hitting fishermanny backwoods exploring Nortoneer here. Have Destination Highways Motorcycle Enthusiast's guide to the Best 185 Roads in Southern B.C. in my hand now with notes. Used it for 5 1/2 weeks this summer , never rained on us once too. (not in the book).Salmon river fishing ,Uclulet,Vancouver island etc. Now this is the way to travel.Lunch in Atlanta Ga.in a few hrs. Having sena in Mexico city tomorrow aft. Then hunting down big ones on the pacific coast. Swordfish n' tunas. Yum. Update - Crazy Combat in pieces ,stanchion tubes shot, Paint shot, primary apart to fit R.G.M. kit on spring return .Enjoy.

hobot said:

A Combat likes 20T better than 19T as allows freeway cruise 80 mph 4000 rpm

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Steve, Windy put a 21-tooth on my Combat in place of the 19-tooth...best thing I ever did since 80% of my riding is in the 80 MPH range. I think you should count your teeth (or look at your tach) as 80 MPH will read approx. 4600 rpm at 80 MPH....not a huge difference, but something to consider at extended times / rpm's at that speed.

I'm pretty sure at some point this spring the combat and I will be traveling thru my 14 acres of woods and 1/2 mile long grass drive to it. I used to drive it with my 75 CB360 regularly. Just because I can, and from what i've seen because it can.

RennieK said:

The thing I envied about Harley riders was their ability to pack a big mama on the back...

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The thing I like about the Norton is the harder you twist the throttle, the tighter the babe sticks to your back.

Dave (dirty old man)
69S

Thanks for all the replies

As someone said above, if you detune it enough the 850 is probably a better choice. Sounds like the Combats can be made reliable and left at 10 to one tho, which is encouraging.
I guess for twoup with gear riding, which is close to a 500 pound load with my 160 lb wife, 230 lb me, two sets heavy armoured leathers and luggage, the low and midrange torque of the 850 is better suited to the job. The 850 Mk3 I have now works quite well for this type of riding.
If I find a good deal on a Combat, as sometimes happens here, Ill plan on keeping it as a hooligan bike or for mostly solo riding.

Glen

Combat is for selfish self pleasing solo riding. Bwolfie break a leg and save us a little property venison.

There is a lumbering sloth of a 18 plus pointer in our woods. It is so large it has lost the graceful gate of a deer and now lumbers like a cow. It has been marked and will be dispatched by bow, gun or combat!

Sounds like a nuisance animal that has been eating all your apples and blocking the entance/exit to Combat access to said property. Check your regulations concerning nuisance animals on private property. Then report the kill to wildlife officials. Then freeze some for us.