What goes in this hole then?

[Mosin]

Chin up Simon, its not all bad, you only have to fit it now! Do you have the special comb? can be done without... just.

Do make sure the tappets are undone so they are completely loose, dont make the mistake of tightening the cover down against the springs as your likely to damage the corner studs. There is a lot of spring pressure there. Give us a shout if your unsure of anything.

Good luck! You'll be riding in no time.  

I bought one of the comb things off ebay while I was at it. I figured that it was probably worth it or they wouldn't sell them would they? Thanks for the reminder about slackening off the tappets beforehand. I've never fitted anything like this before, but realistically, I think it'll be fine. I mean, what could possibly go wrong...?

[chaterlea25]

Hi Mosin,
Two Thoughts!!!!
When reading the thread firstly I thought it sounded like there was some water in your BSA's carb, it would suck it through every so often and the power would return????
Then at the last posting you said that all the oil had worked its way to the sump!!!
How long has the bike been standing?
The smoke your friend following saw could be from excess oil in the crank case
This oil would also lead to the lack of power!
Now I think more than likely that you have a problem with the scavenging side of the oiling system!!
Also maybe the cap in the rocker box was missing for some time and only when there was excess oil in the engine did it leak there???
You should have heard the engine huffing and puffing if the plug was missing?????
My ?0.02 opinion
Regards
John O R

[Mosin]

Hi Mosin,
Two Thoughts!!!!
When reading the thread firstly I thought it sounded like there was some water in your BSA's carb, it would suck it through every so often and the power would return????
Then at the last posting you said that all the oil had worked its way to the sump!!!
How long has the bike been standing?
The smoke your friend following saw could be from excess oil in the crank case
This oil would also lead to the lack of power!
Now I think more than likely that you have a problem with the scavenging side of the oiling system!!
Also maybe the cap in the rocker box was missing for some time and only when there was excess oil in the engine did it leak there???
You should have heard the engine huffing and puffing if the plug was missing?????
My ?0.02 opinion
Regards
John O R

The bike had only been standing for two or three days since it was last run.

It is possible that the plug had been missing for some time, but I had never noticed either the hole itself or any excessive gasping from that area, and I have spent plenty of time recently listening to it. So I am guessing that whatever was filling the hole was still there.

[chaterlea25]

Hi again Mosin,
Theres no way that the bike should have wetsumped in a couple of days,
presumably this had not happened before???
Look carefully at the oil pickup in the sump, make sure its clear,(there is a ball bearing inside this)
was there any gunge on the sump filter?
Before you run the bike again, I would drain and clean out the oil tank
disconnect the oil pipes at the engine and check that they are clear and not collapsed inwards
I would also be sorely tempted to remove the timing cover and remove the oil pump and check the crankcase oilways, especially if you find any muck in the sump or oiltank
Regards
John

[Mosin]

Hi again Mosin,
Theres no way that the bike should have wetsumped in a couple of days,
presumably this had not happened before???
Look carefully at the oil pickup in the sump, make sure its clear,(there is a ball bearing inside this)
was there any gunge on the sump filter?
Before you run the bike again, I would drain and clean out the oil tank
disconnect the oil pipes at the engine and check that they are clear and not collapsed inwards
I would also be sorely tempted to remove the timing cover and remove the oil pump and check the crankcase oilways, especially if you find any muck in the sump or oiltank
Regards
John

*Gulp* That all sounds a bit worrying. Especially as it has never wet sumped before.

[Mosin]

This is all getting a bit daunting.

What I think I will do is sort out the rocker box first (I picked up a new one off ebay and have bought a new gasket set to go with it). Once all this is back together, I will have a look at the oil situation. The pipes too and from the oil tank are virtually new so it is unlikely that they will have collapsed. The oil tank doesn't need draining as it's empty now anyway! I think that I will fill it up with the old oil and leave it standing for a day or so with the sump plug out and a container under it just in case. If nothing comes out, I might replace the sump plug and have a go at starting it briefly. Am I right in thinking that if I do this and I can see the oil being pumped through in the tank that everything is working ok? If all goes well at this point I will divert my attention to the timing as suggested.

Does this sound like a reasonable plan or is there anywhere else I should be looking?

Simon

[RichardL]

Looking back through this topic, I didn't see where anyone mentioned the possibility of a really bad ball check-valve behind the oil pump. Maybe I missed it.

[chaterlea25]

Hi again,
Simon, from your previous message I take it that you have an aftermarket sump plate with a drain plug
While these are great, some lazy sods dont now bother to remove the sump plate every so often to clean the gauze filter sandwiched between it and the crank case!
This is a fine gauze and can  become blocked by crap, this will stop the scavenge side of the pump
returning the oil to the tank,
One time I saw a gauze blocked by engine oil additive, this is so gooey that it clung to the gauze and would not let the oil through!!!!!
Other than that your plan sounds OK, remember it will take a little time for the oil to get all around the engine and enough to gather in the sump for the scavenge pump to return,
Remember there will be bubbles of air in the return oil as the scavenge side has a greater capacity than the pressure.
I never reuse the oil drained from the sump, it is inevitable that some dirt has fallen into the drain tray from the under side of the bike!!!
Best of luck
John O R

[Mosin]

Update:

I have now fitted my new rocker box (what a fiddle that was) and poured the old oil back into the bike. This is just a temporary arrangement until I get it sorted, I have some fresh ready to go in as soon as it is all fixed, but I didn't see much point in putting the expensive new stuff in while there was still the possibility that it may just end up all over the road.

Anyway, plugs in, tank back on and to my not inconsiderable amazement she fired up! I quickly checked the oil return in the oil tank and it seems to be pumping oil through fine which I believe means that the oil pump/lines etc must be ok?

I didn't ride the bike, but just allowed her to warm up. However, once warm, there was a noticeable amount of white smoke coming from the left hand exhaust. There was no smoke at all coming from the right hand pipe. Could this be something to do with the timing being out as previously suggested, or is it likely to be something more sinister?


Simon

[bsa-bill]

'They all do that sir'

Well not all of them but many A10/7s do, it will clear after a couple of hundred yards or so, many theories as to why.
not sure myself just what it is (I suspect guides on mine)

All the best - Bill

[Mosin]

'They all do that sir'

Well not all of them but many A10/7s do, it will clear after a couple of hundred yards or so, many theories as to why.
not sure myself just what it is (I suspect guides on mine)

All the best - Bill

My concern is that she never used to smoke from either pipe prior to the difficulties of last Sunday. However, I shall go and give her a quick run up the road now and see how I get on.

Simon

[Mosin]

Ok, so I have now done a couple of miles on the old girl and the left hand cylinder is blowing white smoke worse than ever through the exhaust pipe. I also notice that there is quite a bit of oil on the left hand side of the cyliner, but I cannot see where it is coming from (certainly not the rocker box though with its lovely new gasket). My initial thought was that it must be a head or base gasket gone and that the left hand pot was over heating and nipping up, but that doesn't explain the fact that I still have pretty good compression on both sides. Or why all my oil drained out of the sump. How had it got there?

Confused and frustrated.

Simon

[rocket man]

i think you should strip the engine down and see if there
is an internal problem cheak pistons and rings and valve
seats i wouldent run her again till you find the problem otherwise
you may be doing more harm than good as for the hole something might
 have dropped inside the rocker box
and may be still in there so i would cheak that first
as it seems youve only had the problems since you noticed the hole
good luck

[chaterlea25]

Hi Simon,
Check that the breather from the bottom rear of the crankcase is blowing out ok, start the engine and you should be able to feel the puffs from the hole!
If the head gasket is leaking into the pushrod gallery there will be a lot of crankcase pressure and oil leaks
Unfortunately it looks as if you will have to strip down the top half of the engine at least
It still doesnt answer why the oil leaked down into the sump though?????
Have you checked that the breather on top of the oiltank is clear?
On the first photo you posted, the links for the head steady are missing, did you take them off for the photo?
Unless the timing was badly out on the left hand cylinder causing overheating / or burnt valves, I dont think timing is the root cause of your problems??
Regards
John O R

[RichardL]

Simon,

And, once you get a look at that head gasket, check it for leakage paths between oilways and the cylinder (they would show as dark pathways). Considering other issues with your engine, it is very likely that the former mechanic (I don't recall that being you) did not thoroughly anneal the head gasket before putting the head on, then, did not torque the headbolts down to their proper tightness. Both topics, anealing and headbolt torque are good for about two hours of reading herein.


Having noted the above, there is still a good possibility that the problem is valve guides. Base gasket? Seems doubtful.

Gents-at-large, what is a good test to determine worn guides? Maybe, fill the ports with thin oil with the head off, wait some time for it to slowly seep through, quickly empty out the ports, then, find some way to exercise the valves to see what comes out? I really don't know and have never tried such a thing, so any known procedure would be good to learn.

Richard L.

Richard L.