Forum

[m1ks]

OK, sit back and relax while I recount a tale of B****rd the Bullet, (I don't normally get the urge to name a machine, but I did last night!)
After rebuilding the top end, MOT'd Monday with a decent 60 or so miles and a few good short runs since, I went for a ride last night, (Saturday), to escape the missis's current olympian viewing and after being stuck at home with Kids TV during the day in between fitting the new rear tyre.
About 10 miles down the road, stopped at a friends for coffee and bike talk, left him to his dinner and carried on.
5 miles further up the road, had that, 'something doesn't sound right' feeling, almost like it was struggling for fuel, just contemplating switching to reserve, (though I knew there was plenty of fuel, thinking starvation through a blockage maybe), and as I throttled off to switch over, rattly chug and stop, pushed into a layby/parking area and checked over, looked OK, tried to start, no compression, none at all, just like the problem I had just after getting the bike and prior to stripping the top end for helicoil, decoke etc.
Checked the plug, decomp, tappets, all OK.
I suspect that on strip down i'll find the rings aligned again as they were previously.
Got recovered home and checked a few things today, oil level was low, (about 1/4 between L and H, from 3/4, drained sump, oil is clean and under 100ml, pumped through well when kickstarter was operated, took off the rocker feed and with some vigorous kickstarter operation was getting a feed to the rockers.
That satisfied my worry that there may be an oil feed problem to the crank or top end though I'm curious as to the loss of the oil, plug is showing a clean burn, nice chocolate brown colour, no oil fouling.
Drained and checked the breather catch tank, about 100ml of milky, (condensation clearly), oil, what are peoples experience, is this a normal amount over 150-200 miles, (with a good bit of starting and running to set up after rebuild of top end prior to MOT etc)
-- I guess i'm looking at a cylinder hone and new rings, hopefully the bedding in of new rings will prevent the rotation in the bore, (anyone any thoughts or experience of this, it's not something i've ever encountered and i'm fairly sure that's what the problem will be given it happened just the previous time)
Pics of oil from catch tank below.

[m1ks]

OK, getting quantities mixed in my head, about 30ml of oil from the catch tank.

[Norm]

So what appears to be the problem, no compression? Don't worry about the oil this happens. Rings lined up unlikely and not a great problem if the do, it happens.If the gaps are ok no big deal.Check the tappets, worst case remove the rockers and see if compression returns. If not decomp is suspect possibly adjustment is too tight.

[simon]

Yes I had this after a rebuild. For some reason one of the rockers became sticky and the inlet wouldn't close properly. Never happened since the second re assembly. Good luck!

[simon]

Oh and make sure it's not the decomp valve propping open too.

[Mark M]

If the rings are re-aligning it could be an indication of a bent conrod or mis-aligned bore. Both have been known on Indian Bullets! Stick with it, you'll get there!
REgards, Mark

[Bullet Whisperer]

It might be as simple as a blown head gasket, like I had recently on a 350 fitted with a composite type. The bike was running very well, then, a sudden loss of power was accompanied by oil being blown into breather catch can and R.H. toolbox. I managed to 'limp' the machine home and after I stopped the engine, it was very reluctant to start, with no resistance to speak of at the kickstart.
Removing the head showed a piece of gasket had been blown out between the cylinder barrel spigot and one barrel stud hole, the 'compression' then leaked down into the crankcase causing oil to be blown out through the breather outlet.
Tightening the head nuts [prior to removing the head] restored some compression, but it was not right and I knew the head would have to come off. You could have a simillar, easilly sorted problem, with any luck. -- Paul.

[another Allan]

Bernard the Bullet.....I like that!

[Midge]

Overtightened rocker studs? common on alloy ones. I doubt total loss of compression is due to aligned ring gaps. I hope your piston is still in one piece! Gunge in the oil catcher is a red herring I expect.

[m1ks]

Update, whipped off the exhaust and carb, (just received my lovely shorty stainless silencer today too, and can't hear it running, darn it), and with the aid of a bright light looking for leaks into the combustion chamber pointed through the inlet and exhaust accordingly, all seems airtight, (or light tight), as I suspected, decomp Is fine, it was lapped in, (along with the valves) and is not cabled so no possibility of it being wedged open.
Thanks for the replies but re the likelihood of the rings aligning being slim, ordinarily i'd say so too, however, just after I got it, having started and run it a few times, it suddenly lost compression, (theres a tiny amount there with your thumb over the plug hole but nowhere near enough), on a strip all was OK head wise but the rings were aligned, the top two were ok gap wise but the bottom oil control ring was outside spec.
So given it's feels just like before, i'm leaning towards this possibility.
Of course, it could yet be the head gasket, piston itself or some such but we'll see when I get the head and barrel off again.
Mark, how would I check the conrod for centralisation and alignment?