classic motorcycle forum
Motorcycle Discussions => British Bikes => Topic started by: dynamic on March 04, 2019, 05:32:54 PM
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I have just started my T 100 after a 5 month lay off repainting frame new rims/spokes etc
it went second kick no problem but I cannot see the oil returning to the tank,
I removed the return pipe and forced oil down it till it was coming out of the end another quick start and still no oil return ?
engine wise before the strip down it ran fine ,I have changed both oil feed pipes and rocker feed pipe for new items with fresh new oil
and replaced the valve springs nothing else was touched engine wise I hope someone can help me out with this serious problem
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I forgot to mention when it first started there was a lot of smoke from the right cylinder I did smear fresh oil around each bore before I replaced the head and my bores are score free , while the engine was out I took the sump plug off and gave it a clean.
I am running + 40 pistons with the left bore measuring 68.54 mm. & the right bore 68.85
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If there is nothing in the crankcase then it won't pick up. fill the rocker boxes up with oil and let drain overnight, if you can get at the oil return pipe inthe tank try a squirt of oil down that, to enourage it.
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thanks for the reply mini me I will do the rocker tip this morning, am I right in thinking that if I'm getting no oil return then the oil is not circulating around the engine at all ? I just don't want to risk any damage to it .
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You may find it will take a couple minutes for the return to get to the tank, which, if you have a lot of oil in the case will be a steady stream which will settle down to random spurts, that is how it should be.
whatever you do, first make sure the pipes are connected the right way round.
After that you have to bite the bullet and have alook at the oil pump, not a difficult task.
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thanks for the reply MM I am going to reinvestigate and will post my findings …………
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I had left the oil poured down the rockers (exhaust./inlet) overnight, so this morning I removed the return pipe and placed it as low as I could & gave it "50+ prime kicks" ign. off
upon start up I placed my thumb over the end of the return pipe and felt a bit of pressure removing my thumb I get an eyeful of 20/50 but even better a steady hiccup of oil from the engine
reconnected the return pipe and starting up I now have a constant hic hic hic of return oil to the tank
thank you all for your input "very relived of Criccieth"
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steep learning but never forgotten.
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indeed never forgotten MM I am educated for the moment thanks for your input
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I nevr had interwebby thing when I started, but I did have a lot of dud bikes :'(
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Yes, we learned about bikes by taking them to bits and putting them back together. If you didn't get them running, you couldn't go to work.
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I have had a slight setback on my machine, I noticed a slight oil weep on the front left cyl. head
so I undid all bolts (in sequence) and went to re torque the head to 25 ft. lbs.
upon torqueing up the top left exs.bolt I stripped the threads "ouch"
so head & barrel off I discover a 3mm gouge at least 1 mm deep & about an inch long this was below the rings so I did not see this when the head was off
so I have now bit the bullet and purchased a new cylinder/piston kit as this was very close in price to having a time sert and 2X new liners + pistons
I am not sure how to stagger the rings when I re fit the new pistons, I read in the manual (not Haynes) just space the rings 120 deg. apart where do I start with the ring gap from the top ( compression ring) ?
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As soon as it's run for a few seconds they will have moved so in my opinion just put the gaps anywhere.
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But to minimise any potential localised wear caused by sharp ring ends space then 120' apart.
I always put the oil ring gap at the back and the two compression ring gaps at the front.
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thank you Ian and Rex I am waiting for my parts to arrive I will post soon on all "progress"
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I've never heard of or experienced wear caused by ring ends.......
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Maybe not, but the little marks are sometimes visible to the naked eye. A sharp edge will always wear more than a continuous curved ring surface.
It's like so many things in engineering, it's reducing the risk of potential problems by following a simple rule.
In the past, people used to say that to have the gaps in a line would "let the compression escape" which really was tripe.
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Hi All,
Recent thinking is that the rings rotate on the pistons as the engine runs, so does it matter where you place them?
I was shown / told to place the ring gaps on the on thrust areas, ie to the sides towards the gudgeon pin
many many years ago ::)
John
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Assuming that all three rotate at a similar speed, then no, other than the initial spacing.
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Hi Rex,
I often wondered how they found out that the rings rotated unless they did multiple assemblies and dismantling?
When I served my time another thing I was told when removing electric motors for repair that had multiple belts on the drive was to mark each belt so they would be replaced in the positions and locations that they were removed and have the same alignment
A while ago I did this when I rebuilt the motor on my lathe (4 belts)
After the first run the alignment marks had all moved by a considerable amount and the marks continued to drift all over the place ::)
John
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Looking after some huge four belt driven vent fans many years ago you could see that only some of the four belts were driving and others were running a little slack.
I put it down to manufacturing tolerances in the belt lengths.
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Hi Rex
When belts are mismatched they can set up horrible chatter and vibration
Matched sets of belts are expensive,
I would think that my lathe belts were the originals but have no way of knowing
John
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Hi Rex,
I often wondered how they found out that the rings rotated unless they did multiple assemblies and dismantling?
https://www.highpowermedia.com/blog/3954/rotation-of-piston-rings
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Hi Ian
Thanks for the link Ian
John