looks nice

Oh bo##ocks!

Years ago, a very good mate of mine was rebuilding a Honda CJ250 engine. He buttoned up the top and and went out to make us a cup of tea. I spotted an old piston circlip on the floor, grabbed it, cleaned it up and put it under the engine. It was worth it to watch the smoke and fireworks - I cracked up just before he took the spanners to the cambox and legged it out of the garage before I was followed by a spanner.

Now THAT, is my kind of humour 

chris846 wrote:Now THAT, is my kind of humour 

Dirty dirty dogs!

I have a flat slab of silicon about 6" x 6" in size that looks an awful lot like a fresh, wet oil slick. It's heaps o' fun to chuck it down under a new bike and watch the smiling rider proudly return to the bike with his keys or coffee in hand. Smile turns to frown turns to worry turns to anger in a hurry. I have not been hit yet.

Boringly back on topic, well nearly anyway, this aspect of lithium iron batteries always makes me smile. When the battery is cold i.e. around freezing, it'll never crank the engine to start with, even fully charged. But if you try a few times, and leave a few seconds inbetween, it'll heat up and its internal resistance or something drops. The battery gets stronger the more you try and drain it. Totally counter intuitive. I videoed it when I started it earlier today. Ambient was around 3' Centigrade and first attempt the battery only cranked it over five times before giving up. You'd think it would never start after that. Yesterday it was minus 4 in the workshop and the first attempt wouldn't even turn the engine over once, still started though.

https://youtu.be/D7nKYVLhchk

Oh, and the bike has also started to communicate in morse code. 
https://youtu.be/WfPb9qtJQLk

Took me a while to realise it, but it translates as "keep your sodding spanners away from me, you know nothing about bikes you moron"

I have personally had two different experiences with Li-ion batteries. My first, and you always remember it, is with a 9amp version which I fit to Big Block. I used it initially for its compact size, but was always wondering whether it would be enough to turn over the K1200 lump which sees relatively infrequent use. On cold days it does as Chris describes: slow crank leading to no crank, then, left for a minute with key and headlight on, cranks as intended and off we go. I rarely use a charger on it. Mainly I'm looking to see how long it takes for the lithium-spec charger to reach solid green all go - about five minutes each time. I never leave it plugged in as in 'tender' mode. It's been in the bike since early 2015 and shows no sign of karking it. I checked it a little minute ago and at rest it read 13.05 volts.

The other version (same brand - Bikemaster) was a 19amp replacement for the typical smaller version we use in K bikes, of the two sizes. I put it into my K1300GT which gets more frequent use than BB. I checked its charge as I do with the Big Block version, only once in a while. After less than a year and a half of use it began to crank slowly so I'd leave the key on a minute. This technique worked fine for a month or so, then it just plain refused to start, the voltage dropping to 9 or so. A quick check with the appropriate charger and it would rebound right up to over 13 volts static in no time. Place a load on it and she'd balk. After 19 months of use it was useless, and out of warranty. I kept it as a test/booster/ornament/I don't know what to do with it battery.

I've been selling lithium batteries on and off since prior to 2012 and recall the old, weak Shorai batteries, many of which we returned under warranty - about half, a dismal record. Shorai are no longer as unreliable as they once were, as I can see from our return rate at the shop. They appear to be as good as any old AGM for reliability and customers who buy them often return for them or other brand lithium for their other bikes. They do seem to drop off, leaving a rider stranded rather more suddenly as compared an AGM or Gel. But man-o-maneshevitz, are they ever light in your overweight K bike!

I have needed two new batteries for two different bikes recently and bought AGM versions in both instances. I suppose I might buy another lithium if I was building a hot rod and trying to hide a compact version under bodywork where I needed to lay it on its side or something or other. Otherwise, nuh, not so much.

Time to swap engines. So a quick compression test of the 'old' engine before removal showed an identical super-healthy 10.75 bar in each cylinder, which kind of confirmed that what I was about to do was a completely unnecessary waste of time.


Not to worry, let's carry on eh? So in proper K tradition I parked this to one side:


Which left this lump:


The ancillaries went on the replacement engine, and it'd "glide through the air with the greatest of ease, that cronky old lump on the flying trapeze"


Shame really. Cos the 'new' engine shows 5.5 bar on lung No.1, and 11.75 bar on 2 and 3  . Might be something to do with that shonky-even-by-my-standards reused head gasket. New one ordered 

Well the new gasket's arrived, turns out that when BMW's marketing department were prattling on about that big and clever "ninety percent parts compatibility between the 75 and 100" they maybe should have pointed out that the HEAD GASKET wasn't on the list. Just another disappointment.

Chris, can't you trim one of the two center cylinder portions out and use it as a two piece gasket? This would add to your collection of fun tails I enjoy hearing.

Just decidin' whether to have the spare bit sticking out of the front of the engine, or the back...

Apparently, a three-pot version of the head gasket is indeed available. The things you learn eh?
So here goes:


It fits really well, what with having the right number of holes n'all.
Which then took me to the next step: valve timing for slackers (previously reported). Just to prove this isn't a laughably unworkable figment of my uncontrolled imagination, here's some piccies:




Dunno where anything was with regard to top dead centre/middle barely alive centre/sideways rather poorly centre, or anything really. Wasn't paying attention. Just threw it back together  .

Next: how to straighten bent valves by eye. Only kidding 

chris846 wrote:Just decidin' whether to have the spare bit sticking out of the front of the engine, or the back...

Wouldn't that mess with water jacket?

"Dunno where anything was with regard to top dead centre/middle barely alive centre/sideways rather poorly centre, or anything really. Wasn't paying attention. Just threw it back together   ."


Now I just want to put a spare part on your bench or floor!


I have too much faith in you to think that valve timing and common sense will not let you figure the solution to your dilemma. If you would "show your work" for my dunce mind.


Also what was the weight of the completed madass?

The Madass, fuelled up and ridden is almost exactly 100kg front & 100kg rear.

Then this fat pig climbs aboard...

Well the spangly new head gasket was fitted, and the first thing I checked was the cylinder compressions. And I kicked myself when it read 6bar, 10bar, 11bar. Because, cyl 1 was was the defective one that led to me taking the head back off and replacing the gasket in the first place. So it looked as if I'd wasted my time and needed to look elsewhere for the problem. Or did it.....

As it happens, Einstein (rubbish bike mechanic) allegedly defined madness as 'repeating the same thing and expecting a different result'. So it made sense to keep cranking the engine and expecting the problem to go away. Which it did   Cheers Alb.

I guess that it might have been the new rings or something, but things improved to 10bar,11bar,11bar. Still not great, but worth carrying on and actually firing the engine up. After a five minute run and LOTS of black smoke (more  )  I let it cool down fully and rechecked the compressions: 12bar,11.75bar,11.75bar Yippee!

....apologies Caveman, just re-read your post 61: I'll post up a more sensible explanation of 'valve timing for slackers' soon