classic motorcycle forum

Looking good though.
Where was the meet?

Thanks! With the short-track tank it's a bit of a looker, it's different to most Featherbed specials (Tritons, Norvins) because they almost always use the big Manx tank (or something like it, Lyta etc) for the extra capacity (and almost all of them are silver or bare metal these days).

Down in Selsey, West Sussex, I think it was a bit quiet tbh, propbably because there was a lot of other meets going on along the South Coast (including the bike jumble at Ardingly which is popular)

Today, after a bit of car booting, (found a large Elora spanner that will hopefully be useful, 1"W & 1.1/4"W) and wandering around town, I popped back into the shed to carry on prepping the bike.

First I drained the old oil, it turned out to be C40 from the last time the bike was run.
It's bloody hard to see into the oil tank...




I've got a couple of litres of new Morris C40...


And I also have these....


The Morris is nigh on transparent when it's clean...


One tin of Castrol is obviously used.... Euuuw


Will have to get rid of that some how... Dad would have just chucked it on a bonfire!

The other tin was still sealed, and is nice and clean.


It looks like the still plenty of room in the oil tank, so I'm going to get some more C40 and top it up to about 3.5 - 4 litres.


In the meantime time I added a dribble of the R30...

After that I messed around for a bit making sure the bike was ready, and prepping a toolkit to carry on the bike, before nipping inside and putting my gear on.

I also remembered to pour some more petrol in the tank!

https://youtu.be/6wWpO-eVKDg?is=A56xX3vfWmoTR-Xr

The first ride was, to be honest, both exhilarating and a bit of a let down!  :lol:

I did a couple of loops around the triangle of roads near the house, and it runs fine, handles fine (the something odd, tyre pressure, a bearing or something), however it's pretty gutless. I wasn't expecting a rocket ship by any means, but it still felt a touch underwhelming. It pulls ok up to about 60-65 then seems to completely run out of wind.

I was going to carry on a bit further afield, but looked down at the engine and realised that the cases were covered in oil, so, I returned home to check things over.






That's after just a couple of minutes back on the work ramp




This is main feed pipe to the pump, dripping wet




This push rod tube is loose enough to be rattled, and is definitely one of the sources of the external oil.


There was so much oil it was pouring over both sides of the cases, although sitting it on the side stand for a few moments would have caused that.


This is somewhat concerning though, a pool of oil by the rear left head stud, seems an odd place for it to be, unless the base gasket has gone already..


The exhaust "was" nice and shiny...


The plug actually doesn't look too bad if you ask me.
It's not quite right, but I've definitely seen worse!



I left it to cool off before I clean it up, then may look at reducing the amount of oil being pushed to the head, one of the books says it should be " a drip for every 2 pulses of the pump" (you can see the pump pulses through the window on the pump), but that's a rate for racing WFO, so I think I'll reduce the feed to a drip every 3 or 4 pulses, and try to do some mitigating of the leaks!

There's also lots of other little niggles, the gear lever is a bit high, the nose cone isn't straight, the left fork leg seal has gone, etc etc.... nothing insurmountable though. But some things are fine, the rear brake works perfectly, the front is okay etc. So I need to do a few more things before it's fully ready...

That said... It's the local classic club monthly show tomorrow, and that's only about a mile away from the house...

Good stuff.
I know you believe it to be the fuel filter lip, but on most recent new carbs I've bought the very thin fibre washer is too stiff to flatten and seal, but after a night of soaking and swelling, a quick tighten the following morning sorts it.

I can see the fuel weeping from the upper part of the banjo union, the upper part is wet when the lower part (where the washer is) is dry.

The only other explanation i can think of is that the metal banjo union itself has a flaw, it's the next thing i intend to look at.

It's a nice Thursday afternoon - I really ought to be enjoying the sunshine.

Hey ho, back to the shed.

First thing I did was have another go to see if the mag was producing sparks: It was, they're not huge, but they're there.



So I pulled down the tank, after pondering which needs to be fitted first - seat or tank. 
It's a bit easier to fit the tank first.
Here's the first problem...


Petrol hose is about 2-3 inches too short now.

Luckily I had grabbed Dad's filthy bag of filthy hoses last time I was at the old folks home.


Found some nice unused braided fuel hose, which matched what was already in use, and there's plenty of it.
I still trimmed it a short as I thought I could get away with.
(The whole bike is built up "as if" it were a race bike, lightweight, minimalist etc, so I may as well carry on that theme where I can).


Re-fitted the oil lines.


I then tried to get it spinning enough to check the oil was flowing, which proved a thankless task. I even pulled the feed off the pump to check there was flow from the tank, which there was.

So, I stood looking at it for a bit....

Then realised I may as well give it a kick, so splashed some 98Ron E5 into it...



https://youtu.be/uREKeUSCjrE

HOLY $%^&&ING SHIT!!!  IT'S ALIVE!!!!

MUWAAHAHAHAHAHAHAHAHAHAHAAH!!!!!!

I genuinely swear to any deity you choose, that was the 2nd time I kicked it with the plug in!!

I will admit, the first kick was promising.... there was a "crack" of a very definite ignition, it just didn't catch.

I am SOOOOO $%^&&ing chuffed right now!!  When I stopped the video I was laughing manically and couldn't stop myself for a minute! 

  :banana-wrench:  :banana-wrench:  :banana-wrench:  :banana-wrench:  :banana-wrench:

I still can't believe it fired up so easily!!

There's still a fair bit to do before it's road-ready, but most of it is tinkering, then tuning the carb a bit and making sure it's the ignition isn't "too" advanced - but $%^&& me... I am gobsmacked.

Well, they say you never know until you look....

So today I took a spin in down to Selsey, where I'd seen a large JAP branding on one of the small garage-type buildings.  What do you know, right by the sea there's a guy who builds and raced JAP grass-track bikes and Formula 500 cars. 

I'd spotted the place when we first moved here, but today was the first time I'd actually walked through the door.  Face to face really does make a difference. Lovely guy, very very knowledgeable and he pulled a oil union from one of his old rocker boxes and let me have it!  In turn I gave him my details with a promise that if he needs a pair of hands in a rush, I'm only 10 minutes away.

Turns out the union was still BSP, but i was able to adapt it, running a die down the thread does seem to have worked (and I needed to clean the thread in the rocker box too, obvs),  but the union has fitted beautifully now.

Seeing as I was on a roll, I fitted the oil line from the pump to the head while I was at it.

(yes it needed 3 copper washers....)



Pump end.


Then I removed the two large bolts that hold the rocker box down, and fitted the head-steady, this is why I needed the oil union before I could get much further - you can't fit/remove the oil union with that head steady in place.


My Dad never learned to weld....

(mind you, I haven't yet either! )



I even got as far as wiring up the Mag to see if there was any sparks!


And there were! 

but they were pretty small and weak... so it could be a shite plug, or well, we'll see...

Took the timing wheel off and put the primary gear cog in place, but haven't done anything up yet.



Next time I'm in here... it's just a case of bolting on the front engine plates, and doing that nut up TIGHT (with Loctite)....

And....

I can put it in the frame....

Well.... first I have to figure out where the bits I still have left over should have been fitted....  worryingly... one of them is a rather large diameter, but shallow, nut.  IE it seems like a specific use-case nut....  oooo-er...

Back in the shed of prevarication....

Well, actually.... progress has been made.

As promised, I tested the cam lobes by the simple mechanism of throwing the cam shaft into the pillar drill and setting up my magnetic stand for a dial gauge.

i tried the digital gauge first, but it was just too hard to follow, so I dug out the needle gauges.


First try, but then I realised that the gauge wasn't being held very well, so there was a hiatus of sorts while I fecked about with the gauge clamp on the stand...

And eventually gave up and used the other needle gauge which isn't as reliable... but should be ok for this.

Here's a couple of lovely little videos...

Ignore what I'm wittering on about in the video re which lobe I'm looking at, I got confused.
This is for the exhaust lobe
https://youtu.be/i2biE-Sa9tY

And this is the inlet.
https://youtu.be/N-WmMQ_Oddc

It might LOOK like the inlet would be the first lobe that's activated when you look at the camshaft... but note that the cam followers are not inline with each other, they're either side of the camshaft, so as the camshaft rotates, the exhaust follower is actually the first one that's actuated.


Anyway - the cam seems good.

I also rotated the timing chest with some oil drizzled over the actual gear-teeth of the camshaft and half-time pinion.... which I realised that I hadn't done yet!  the click-clack was definitely reduced when I did that... so I think it's just the backlash that is inherent in the system, and I'm being way too anal about it*.   

So i also checked the backlash again (at a point where both valve springs are partially compressed), and it's no more than a degree, if less.  Which is inline with expectations, so I pondered while I took a drink, (Fever Tree Mexican Lime Soda if you're interested), and thought.. $%^&& it.

So I assembled the timing gear for the final time and also decided to make a new timing cover gasket, because the one I'd been using had got very oily and I wasn't sure if it would take the 3Bond very well.

So - here we go again:
Cut the a blank bit.


Leave it under something heavy for a short while to ease the bend .


Basic outline and as many screw holes as I could get the pen to work with.


Half way through the dinking.


So - new gasket.

I also remembered a bit of advice I'd seen and found  a short length of "wire" to make sure that the oil-feed quill is inline when the timing cover is fitted.


(yes, I spotted that bit of gasket paper...)

Fitted the push rod tubes



Fitting the cover, making sure everything is aligned



Timing cover buttoned up tight.  New gasket was fitted with 3Bond.  The  gasket is so thin, I just spooged out an excessive amount of 3Bond from the tube and brushed it onto the gasket paper thinly with my fingers.



remember to pull out the guide wire....  do NOT want that to wander down the crank shaft....


Then placed the Magneto, fitted the sprockets and chain.


There's no keyways on either of those sprockets, they're held solid by the nut pushing the sprocket onto the taper.  I messed around for a bit getting the camshaft sprocket done up - eventually got it done up "tight" by putting the plug into the head and working against the compression, but it wasn't ideal.  So once the Mag was tightened down with chain tension, I had another go at it, working against the locked mag spindle.

 Mag chain in and tensioned.


With some movement, but not too much.


The combined backlash between the timing disc on the crank output, and the locked magneto spindle is about 10 degrees!!   So ignition timing will be approximately correct at best....

I timed it to 34degrees  before TDC, which... according to one of the books, is correct for a 350 at 15:1.... but this bike is about 400cc... running a much lower compression (estimated 9:1) so none of the ignition timings mentioned in any book will be correct, so I've chosen a starting point and will work from there.

This is the "drive plate" for the Pilgrim Pump.


It drives that little thing there.


Don't forget to cover over the Mag's spindle lock hole



Just showing here that even with the chain cover on, I can still get at the mag spindle to make ignition timing adjustments.


And the little cover in place


I didn't bother trying to seal the chain cover, I expect it might come off again reasonably soon....

Fitted the upper valve covers.


And, while I was at it, the return tube for the sump-return pump. (I expect that would be a pain in the arse to fit once the engine is mounted.)


I also, luckily, remembered to fit the mag-platform brace.

The next thing I need to do is sort out the Rocker box oil feed union, which really is absolutely knackered, not only are the hex-flats nearly gone for fitting it, but the thread for the nut that holds the banjo fitting on is absolutely $%^&&ed.

I managed to talk to another JAP expert the other day, and got a bit of a dressing down for not being pro-active enough, eg not having my own lathe, to be working on old bikes and engines.  He also said that I was making a mountain out of a mole-hill with this banjo post business. 

Which I thought was a tad harsh, but he did have a valid perspective at least, so I need to find localised "mate down the pub" for some of the more engineering-ey work.  With any luck....


One other thing he suggested though was taking the 1/8" BSP 28tpi oil union and running a 3/8" BSC 26tpi Die down it.  His thinking was that the thead is only about 3/8" (if that) and over that short distance, the thread-form is close enough that the die won't destroy the BSP thread, but will cut a usable BSC thread-form.  I'll hold that thought and if I can't find a BSC union then it's an option to try with a new steel post from the suppliers (who are adamant that they only have the BSP unions).

Could it be the backlash in the cam gears when the torque on the cam is reversed as the follower goes over the peak ? This would be more noticeable when turning slowly.

The current thinking is that its something along those lines.

What's got me confused is that the guy who has done 100s of these engines has not experienced this noise before. If it was something expected like that backlash you'd think he'd have seen it at some point in his career.

More tinkering today....

I'm still trying to figure out where this clacking noise is coming from, and after a bit of fiddling about, it occurred to me to try rotating the engine within the timing cover off again.  I was trying to figure out if there was a worn interaction in one of the ball joints (either end of the pushrods).

With the timing cover OFF, the clickety clack is NOT there.  Whatever is causing this is only in effect when the Timing chest cover is fitted.

So - I continued trying to figure out what could possibly be happening.

I dug out a 1/2" length of rod so I could assemble the timing components in the cover, rather than the cases (to see if anything was interfereing)

First the rod needed a tad of tidying up. (No idea what it was originally)


It just needed to allow the cam-followers onto it, so rough was good enough.

I can confirm that there's nothing interfering due to the timing cover.



So - with more investigation... we get more information.

And here's a video explaining what I believe i have discovered.
https://youtu.be/HmQjgWlt1uA

So my choices are:
Order a new pair of bushes and in the meantime, strip the entire thing down again, with no guarantee (despite what I believe) that this is a solid fix;
Or:
Accept this slight looseness and carry on, knowing I'll need to strip the engine again at some point soon(ish) and accepting that there'll be a tad more wear happening in the current bushes. I don't know what that movement will do to the rest of the components: ie. what extra wear (above the usual) would be caused by carrying on.

Difficult decision. (I'm currently waiting to see if I can get a chat with the Guru to se what his opinion would be). Stripping the entire engine down would be somewhat demoralising at this point, even though I now know how simple it actually is.  It's more the faff of stripping and cleaning the sealants and re-making gaskets etc that puts me off.