Do I need a refresh?

[Oldhaven]

Where will I get a blanking cap for the chain oiler up at the base and back of the oil tank on the UFM? I will keep the cadmium plated copper tube for another owner in the future, should they want it, however, I would prefer to use a proprietary chain wax and not have oil everywhere over the frame, rim, tyre etc.

Kenny.

Over here in the US these BSPP fittings are hard to find, but I ordered a couple of 1/4 BSPP Hex head high pressure plugs that have a rubber sealing washer from McMaster Carr, item number 4936k177 for $3.06 ea. I also got a 3/8 BSPP plug 4936k178 for the return port so I could completely block up the UFM for cleaning. These stood up to acetone and other noxious chemicals, and I will be using one to block off my chain oiler/tank vent port just as you mention. They are designed for 3500 psi so should be quite leak proof. I am sure they are easier to find there. As I type this I can hear Big Sid in my ear cautioning to make sure the vent hole is clear in the oil tank cap.

Ron

 

[Oldhaven]

I also got a 3/8 BSPP plug 4936k178 for the return port so I could completely block up the UFM for cleaning.

Ron

That should read " for the feed port"

 

[KennyNUT]

Hi Chaps,

Many thanks for your different suggestions including the offer to send a petrol union nut. I didn't have anything to hand and I liked the idea of the cadmium pipe remaining in situ.

So here is what I did (I can hear you all cringing now ), I took the end of the cadmium plated copper pipe and flattened the last inch of the pipe in a vice and folded it over and flattened it again, checked it was air tight by trying to blow through it (it was) and re-fitted it. It looks like the oiler is in place, but its not visible that it is sealed off (that part is hidden behind the chain guard).

So how do I know it didn't leak oil - well I had the Comet engine running this morning and no oil leaks.

I replaced the timing chest washers, refitted a new gasket and cured the thinnest smear of sealant on the cover side, pieced it together after replacing the old pushrods with new ones and adjusting them, added glaze-busting oil from Millers (20wt) and it started second kick - great news.

The bad news is its still smokes , however, it has great compression (from the foot and knee gauge). It definitely feels a bit more of an effort to turn over, but it caught nicely and restarted a couple of times thereafter, without choke.

I have decided the best thing to do now is fix up the other stuff that was on my "to do" list over the winter and then just ride the bike, and hopefully, one day it may become a non-smoker.

Any thoughts on the smoking part would be appreciated, however, I am less worried about that now I have seen inside the engine know that it is all pretty new and the head has been given a clean bill of health and the barrel has been deglazed, new rings carefully fitted etc etc.

What's left to do:

1. Devon Rim Co are doing my new stainless pinstriped wheels end of January (very busy)
2. I just want the brakes chamfered to see if they can perform better (surely that's possible) and I will get the hubs and drums 2-pack painted
3. Downpipe re-chromed along with oil and petrol caps
4. Tank repainted

and to finish off;

RIDE THE BIKE!

Turned out to be a bit more than just a refresh, but great fun, nonetheless.

 

[Mark Fisher]

Hi Chaps,

Many thanks for your different suggestions including the offer to send a petrol union nut. I didn't have anything to hand and I liked the idea of the cadmium pipe remaining in situ.

So here is what I did (I can hear you all cringing now ), I took the end of the cadmium plated copper pipe and flattened the last inch of the pipe in a vice and folded it over and flattened it again, checked it was air tight by trying to blow through it (it was) and re-fitted it. It looks like the oiler is in place, but its not visible that it is sealed off (that part is hidden behind the chain guard).

So how do I know it didn't leak oil - well I had the Comet engine running this morning and no oil leaks.

I replaced the timing chest washers, refitted a new gasket and cured the thinnest smear of sealant on the cover side, pieced it together after replacing the old pushrods with new ones and adjusting them, added glaze-busting oil from Millers (20wt) and it started second kick - great news.

The bad news is its still smokes , however, it has great compression (from the foot and knee gauge). It definitely feels a bit more of an effort to turn over, but it caught nicely and restarted a couple of times thereafter, without choke.

I have decided the best thing to do now is fix up the other stuff that was on my "to do" list over the winter and then just ride the bike, and hopefully, one day it may become a non-smoker.

Any thoughts on the smoking part would be appreciated, however, I am less worried about that now I have seen inside the engine know that it is all pretty new and the head has been given a clean bill of health and the barrel has been deglazed, new rings carefully fitted etc etc.

What's left to do:

1. Devon Rim Co are doing my new stainless pinstriped wheels end of January (very busy)
2. I just want the brakes chamfered to see if they can perform better (surely that's possible) and I will get the hubs and drums 2-pack painted
3. Downpipe re-chromed along with oil and petrol caps
4. Tank repainted

and to finish off;

RIDE THE BIKE!

Turned out to be a bit more than just a refresh, but great fun, nonetheless.

Kenny, not the best time of year I know but, if the bike is rideable I would try and get at least a hundred miles on it. You might find that once everything settles down and the rings have a chance to seat/ bed in etc, your smoking issues may well disappear. Then you can take care of the other issues safe in the knowledge that the engine is good to go. Don't be too gentle with it but don't go mad either, running with a bit of load and a few heat cycles should be good for it. The bike won't be fully broken in but it should be enough to deal with the smoking, if it doesn't then you have another issue, over oiling, breathers etc.
good luck

 

[Alan J]

Well., Kenny-don't worry about breakdowns! It is accidents you have to worry about! My old "outfit" has carried me and my family over 180,00 miles and only once been taken home by breakdown truck! p.s.- what's a"mobile phone?" [only joking!!"]

 

[nkt267]

Don't be too gentle with it but don't go mad either, running with a bit of load and a few heat cycles should be good for it. The bike won't be fully broken in but it should be enough to deal with the smoking, if it doesn't then you have another issue, over oiling, breathers etc.

I found with my Comet that under 40 mph was a little too slow for running in and found that the bike was a lot happier at 45 with brief trips up to 50 for the first 100-200 miles. once I knew that it would not nip up I brought the speed up to 50-55 mph for the rest of the running in period with occasional bursts up to 60. Don't let it 'slog' uphill, better to drop a gear or two and increase the revs to make it comfortable..You will soon feel where the bike is happiest , it's not the speed that counts but how happy the engine is whilst running in..John

 

[KennyNUT]

Thanks all for your encouragement and "running-in" advice. The bad weather is moving in now, so I will focus on getting all my other jobs that I am outsourcing ( ie beyond my technical capability, available time to learn etc) shipped off before Xmas and put those finished items back on with care and start the process of riding the bike in early Spring. I hope those smoking issues go away, as suggested.

Merry Xmas everyone.

 

[greg brillus]

Kenny, just a short point regards to your smoking issue, and this is a good one.....It may be that the smoke is from the left over residual oil built up in the exhaust system, which will get hot and burn when the exhaust heats up. If this is the case, once you do manage a couple of descent rides.....you may find it disappears, as it looks as though your engine is in a good state now, Cheers and good luck.......Greg.

 

[KennyNUT]

Many thanks, Gregg.

A quick update on progress (for those interested) is that

1. the hubs and flanges are all now powder coated after dismantling the wheels as they were on the bike
2. the brakes have been relined and the drum facings have been skimmed to make good contact across the face of the shoe, something that was not evident from the wear patterns on the front shoe linings
3. brake plates and drums are all off to be powder coated now, not two pack coted as I was thinking earlier. The powder coated finishes that I have received back have been very good indeed, glossy and smooth
4. I await an update from the Devon Rim Co on my painted SS rims and spokes, however, I don't expect that till later this month
5. Tank is in progress with "The Finishing Touch" to be stripped back and refinished and again I don't expect that till later this month

So, today after a discussion about my carburettor with a mate, Rob (Black Shadow owner and nearby/supportive VOC member), I had been looking at potentially replacing it later in the year as I was not experiencing a steady idle. I checked the slide and it rattles inside the carb body, so I am assuming that air can whistle past and the air/fuel mix can be inconsistent. Further up the rev range the bike runs fine, though not with startling performance, but probably right for a Comet. The carburettor shows a lot of wear on one side as per the image showing the shiny and scratched brass slide below inside the carburettor body. This is presumably because of due to the suction forces from the piston on the inlet side.

The other side of the carb (bell mouth) is dull and presumable is not where there has been so much wear.

So after a discussion with Mr Martin Bratby this afternoon, he will bore out and re-sleeve the carburettor body and either replace the slide or machine it for a snug fit for me. Whilst in his possession he will check over the rest of the carburettor and replace anything that is worn or unserviceable. His pricing seemed very reasonable and he had about 50 carbs before mine to fix up. He quoted a 6 week turn around time which I think is just fine given the time of year and for me there is other work I can get on with.

I think that should see to the inconsistent idle that I experienced, sometimes ok, sometimes fast and free up some attention at junctions rather than listening to catch the revs before pulling out, not too bad and not all the time, just a small nuisance.

One final note, I don't endorse anyone's work that I may have mentioned, only that I have received excellent advice from VOC members and friends. I have no complaints about any work undertaken by those mentioned during the work on my Comet. There that's that said!

Cheers, Kenny.

The next update is likely to be in February, so in the meantime, I wish everyone a VERY HAPPY & HEALTHY NEW YEAR!

 

[Bazlerker]

I had my carbs sleeved with steel , and the body bored about 25 years ago...best thing I ever did..