Newest Member with a few questions

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Hello everyone...I have been absorbing as much of the excellent information and advice on this forum over the last two weeks. I have the opportunity to purchase a '72 Combat Commando, and am well aware of the issues with the Combat spec engines. Engine had a total rebuild ten years ago, with appropriate Superblend replacements. Transmission had a complete over haul and upgrade two years ago. Isolastics will probably need replacing, of which I should be able to do, except for the rear I understand it usually involves a teardown of the engine and transmission from the frame. There was some post somewhere by someone that I read, where the chap removed the final drive chain and was able to sling the frame from above his ceiling, allowing the swingarm to swing below the engine cradle, thus allowing access to the rear isolastic, and he posted that it was not difficult. Well, it's worth giving it a go, if I get the bike I am interested in. The only other issues with the bike is the right exhaust header is bluing, with what appear to be burn spots on the bottom just before the silencer. The current owner says the primer (tickler) on the right carb is not functioning. I would think that that carb is running too lean a mixure causing the bluing. Also there are no chokes on the carbs, but that's what the primer is for. The other concern is that when looking at the bike from the rear, the rear tire appears to line up fine with the center of the bike, as does the rear mudguard. However, the top rear mudguard support behind the seat and the seat are cocked over to the left of the bike off-center. Now it does look odd, but I wonder if this is normal. I would like to post a picture of the rear, so you lend me your opinions. How do I post a picture? There wasn't any instructions in the FAQ's.
Thanks, looking forward to becoming a Norton owner soon.
 
You can always tell when people say that they read everything but miss this part. :D

Depending on where you live it might make a difference on if you can go without chokes. You do want to get the carbs sorted sooner or later (as you can guess, sooner might be better).

Unless the bike handles funny or vibrates badly you might be able to put off the rear isos. If not, well, you sure seem to have a handle on the fix.
 
Hi Singring,

Look at the avatar on the right. This is the rear of my '72 750 combat roadster. Everything should line up. Suspect you may have some frame bent.
 
It is possible to change the rear isos without removing everything. Check the archives on the INOA Yahoo list. There is an excellent explanation by Mike Taglieri.

Russ
 
OK, I hope I am doing this correctly. Here is a photo of the rear of the bike...tell me what you think

Newest Member with a few questions
 
Somebody doesn't have a tape measure, or much of an eye for what's straight. Personally I'd need the bike in front of me and some measuring tools and equipment handy.
To start with that rear fender is not even close to centered.
You ought to get that looked at by a pro if you are not familiar with these bikes. What's up with that hose clamp from the header to the frame?
 
Here is a shot of the blueing exhaust header. The left side is starting to get a gold color to it.

Newest Member with a few questions
 
batrider, could you please provide me with a link to the isolastic replacement procedure that Mike Taglieri posted at INOA Yahoo list. I'm not familier with that forum.
Thank you
 
I looked it up earlier...go to yahoo...then groups...type in inoa. Once you join it's in the files section. It tells you how to get them out, but not how to get them back in. :shock:
 
Hi Singring,

Nice photos :D

There is a "U" clamp that goes around the rear frame tube and holds the fender and tail light in place. Loosen this and push the fender to the drive side, it's adjustable. The seat cover is not on straight - pushed to the drive side, so makes the whole thing look worse. The issue that really troubles me is the rear wheel seems to be leaning to the drive side. That's not adjustable and could indicate a bent swing arm. If it is bent the next question would be how did it get that way and what else got damaged.

As Cookie mentioned "what's up with hose clamp holding the right side exhaust pipe to the frame"? Could be the exhaust port threads in the head are stripped so the PO needed to hold the pipe in place. This can be fixed.
 
I was wondering if they had tried to compensate for the possible bent swing arm by misaligning the fender. That's why I thought it would be good if it was looked at by a pro.
It used to take me a long time to check frames with a level and a plumb bob, nowadays a laser would make that easier.
 
The first photo certainly seems to show something is out of alignment at the rear?

The second photo shows a metal band or pipe clip holding the exhaust pipe to the frame? You need to find out why it's there, because it shouldn't be necessary, if the pipe is tied-in too tightly against the frame, then it is eventually going to break.
 
Here's a repost on the rear isolastic removal/replacement. Credit goes to Mike Taglieri. I added the stuff re Alternate Method.

From: Michael Taglieri
Date: Mon, 3 May 1999 01:30:01
Subject: Easier Way to Rebuild the Rear Isolastic

* See note at end re: alternate method I used on my 74 Roadster.

 The standard workshop manuals for the Commando generally tell you that
the rear Isolastic mount can be rebuilt only by removing the engine, or
even the entire power train. Today, helping Chuck Contrino rebuild the
rear Isolastic on his '72 Interstate. I was finally able to test a
procedure I've been contemplating for a long time that lets you rebuild
the rear Isolastic without significantly dismantling the rest of the
bike. It worked very well, and this is how you do it:

1. Remove the tank.

2. Remove the primary (optional -- see below).

3. Remove the horn (optional -- see below).

4. Remove the air filter(s) and the exhaust pipes.

5. Put the bike on the centerstand and fasten the centerstand with safety
wire, electrical ties, bungee cords, etc., so it cannot possibly
collapse. Do not fasten it to any part of the frame, but only to the
engine plates or some other part of the bike that hangs on the Isolastic
mounts.

6. Slightly loosen the nuts on the large central bolt that runs through
the rear Isolastic, and also loosen the nuts on the headsteady.

7. Put a small hydraulic jack, etc., under the middle of the left frame
tube (with padding to protect the frame) and slowly raise the side of the
frame until the left foot of the centerstand just leaves the floor. At
this point, the weight of the frame does not rest on the central bolt of
the rear Isolastic, and you can remove it easily. Using a suitable drift
(a 1/2" socket extension works well), tap the big bolt loose, catching
the various metal parts of the Isolastic that fall free when it's out.
(By the way, using a hydraulic jack this way is also useful for getting
the bolt back IN when you're done, and you can look through the hole with
a flashlight and move the frame until the parts are exactly aligned).

8. Lower the hydraulic jack. Now the frame is hanging on the powertrain
by the front and top Isolastics, and the top Isolastics show it by
twisting slightly under the weight. Lift the rear wheel (with a 2x4",
brick, etc.) until the top Isolastics are no longer twisted. Now, remove
the side plates of the top Isolastics. (You do not have to remove the
engine steady from the top of the engine).

9. The powertrain is now resting on the floor, held up the centerstand,
but it's attached to the rest of the bike only by the front Isolastic.
Now, put more stuff under the rear wheel to raise the frame until the
centerstand almost comes off the floor.

10. At this point, the frame tubes are out of the way and the rear
Isolastic is completely exposed on both sides for rebuilding.


 THE "OPTIONAL" STEPS: If you didn't remove the primary, the Isolastic is
completely exposed only on the right side (see Alternate Method below: on my bike it was only partially exposed), and you will need some kind of
hook to pull the rubber parts out. If you didn't remove the horn, the
frame tubes will be partly out of the way but not entirely. I recommend
taking off both of these items if you're removing the original Isolastic
rubber parts, because if they're truly stuck in there, it's a %$#@ of a
job to get them out. On the other hand, considering how awful a job it
is to remove the horn, you may want to try this first with the horn in
place and remove it only as a last resort. (By the way, if you pound on
the central rubber with an ordinary drift to get it out, the rubber
absorbs the shock of the hammer blows before they get transmitted to the
edges. The best way is to pound on the edges of the rubber by using a
very large socket on an extension as your drift).

REMOVING THE HORN: As anyone knows who has tried it, this is one of the ultimate bastard jobs on the bike. You can do it with the rear wheel in
place by unbolting just the front part of the rear fender (two bolts near
the top, two nuts on studs near the bottom), and flexing the fender
enough to "pop" it off the studs and move it down. These studs turn out
to be the bolts that hold the horn mount, which you remove (teaching
children in the area several new words in the process). Finally, you can
squeeze the horn out of the space between the frame and the fender --
moving the rear axle as far back as you can will help.

Once you've got the rear Isolastic exposed, the manual explains the way
to rebuild it. Chuck decided to install Mick Hemmings' vernier Isolastic
conversion collars on his bike, and I may wind up doing the same -- it's
astonishing how well-machined these pieces are. I almost wish I could
afford to buy an extra set to frame and hang on my wall.

Alternate method I used on my 74 Roadster
Rather than using the centerstand, I had my bike (a 1974 850) on my lift with the front wheel locked in the wheel vise, centerstand up. (No worry about tipping the bike over when jacking it off the centerstand and it is a one person operation.) No need to raise the rear wheel as described above, but it still requires the preparation described in #1 thru 4 above. Put a hydraulic jack under the engine plates with a piece of 2” X 4” wood on top of the jack to push on the engine plates. Jack it up so that slight pressure is placed against the engine plates. This will hold the engine/gearbox up when you remove the rear Isolastic bolt. Remove the Isolastic bolt. The end caps, PTFE washers, etc. will come out at this point. Remove the head steady side plates. Loosen the front Isolastic bolt, but do not remove. Now the only things holding the engine/gearbox in place is the front Isolastic and the jack.

Slowly lower the jack and the engine/gearbox will pivot off the front Isolastic, drop down, and the rear Isolastic will start to clear the “Z” plate. I left my primary on. The rear Isolastic would not completely clear on the right side as described by Mike Taglieri above on my bike as the primary case rested on the left frame tube preventing it from lowering any further. However it was low enough and exposed enough (about ¾ exposed) that I was able to get all the rubbers and buffers out of the rear Isolastic tube with little effort. In fact the right iso rubber was a very loose fit and almost fell out. The center and left ones were snug and appeared to be in good condition, but I replaced all three since I don’t want to do this job again anytime soon.

Installing the new isolastics was easy. I cleaned out the tube, greased it with silicon grease and greased all the isolastics. I put the left iso in from the left side. Then from the right side I put in the spacer, center isolastic, another spacer, and the right side iso. I had to tap the center iso in using a long ratchet extension as a drift. You do not need the Norton special tool to get the isos in—you just have to work them into the tube with your fingers. The grease makes it pretty easy. Then you have to add the end caps, PTFE washer, collar and boot. Now jack it back up to line up the hole. The hardest part was putting the long stud back through all the various spacers, Z plates, etc.

I use Mick Hemmings vernier adjusters. These can be used on pre 1975 Commandos without any modification. I understand the Mark III style is easier to use though I have never seen them.
 
Wonder if the clamp is an attempt to fix the kickstart hitting the pipe problem, its fitted at the point I hold the pipe and press it towards the frame when I am tightening up the exhaust ring to make sure the kickstart clears the pipe.
 
Singring — I recently replaced the rear isolastic mount on my 850 with the engine in the frame. What you want to do is just about do-able. I read Mike Taglieri's article before I did mine. But eventually, I decided that it was too awkward and I took the gearbox and cradle out. In any case, you would really have to remove the primary drive completely, so removing the rest after that is not so bad. Having the cradle on the bench means you can check if the ends of the tube holding the mount are flat, so that you get an even clearance all the way round. It's also much easier to install and centralise the mount in the cradle (assisted by some rubber lubricant). If you need more details on how I did mine with engine in frame, email me.
 
I would be very concerned about the bike from the look from the rear. I also believe the fender has been mis-aligned deliberately to line up with a rear wheel which looks out in both the vertical and horizontal planes.
The bike looks rideable.....have you ridden it? Can you let both hands off the bars when coasting?
You should be able to coast down the road with no hands and use your body to go round corners.
I would line up the rear wheel to the front and see what it tells me.
I bought an Iron Head Sportster a few years ago with a rear end shunt and stripped it and had the frame re-aligned for 40 quid (and a lot of my own time stripping and rebuilding!). Didn't even need to paint it after. Harley still handled like a bowl of jelly in a paper bowl, but the frame was straight. :?
The bike looks great but it could be a serious load of work if the frame is twisted. Also look for signs of an impact elsewhere on the bike.
Stu
 
I have been in contact with the owner via email and phone, the bike is located a couple of days drive away. I plan on testing the bike in person before purchasing, but want to get as much info, expert opinions, and such before I bother to make the journey. Bike has 14k miles on the speedo. After the responses from you fine fellows, the owner confirms that bike rides true, and handles fine. Bike engine was rebuilt 10 years ago, transmission rebuilt 6 years ago, has a recent new clutch, original points ignition system, but have been recently replaced. Owner says in the last ten years he averages 100 miles use per year, as he also owns two Harleys that he rides everywhere. The Commando is mostly ridden in town, not above 4000K revs, engine not de-tuned as it has a wollap for compression. Owner seems above board with all questions, but dealing over the phone....well, you know how that can go the other way. So, it would appear that the Combat engine overpowers the tranmission and clutch. It's an engine that shouldn't be wound out, even with the Superblends installed.
Many thanks for all your advice.
 
That might be the case, I also assumed it might be fixing a stripped exhaust nut. In general I see things on this bike that would worry me a bit. You can fix anything, but there should be no need to pay top price and then have to change something big, like say a frame.
Pictures can only help so far on something like this.
 
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