2003 Royal Enfield 500 Deluxe

I have no idea what kind of ignition is present on the '03 Bullet, but I've seen carbies blown out of the boots on several XS650s when the following conditions were present: Points ignition, advance curve stretched due to worn bob weights in the advance governor, timing set at full advance with retard timing left to fall where it may, with said retard timing falling close to TDC (way too retarded). I have never seen XS650 carbs blown out of the boots without finding severely retarded ignition at full retard and worn weights as described.
So you're saying retarded to the point that we go through power stroke, through exhaust... and arrive at intake with the charge still burning because it fired so late?
In my full advance scenario you'd expect (require?) the kick starter to kick back pretty severely. Lacking that kickback, I'd say that too retarded is the more likely scenario.
 
Got no theory, Jim, only experience. Every time I've seen carbs pop out of boots on XS650s I've found retard timing to be too retarded due to stretched advance curve due to worn bob weights. Of the many methods for restoring the curve I like gggGary's best (shimming the tabs on the governor body). I like it better than the method I used to use (beating the tips of the bob weights until they expand and take up the slop in the slots in the disc.)
 
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Best to just jump in. On a scale of 1 to 10, I'd rate a points system as "stupid simple."
My peepers ain't what they used to be either. I've got various el cheapo reading glasses scattered around. For small stuff such as points, grab the strongest pair at hand.
With you there Jim; I have ready readers everywhere about the workshop and home ( £1.50 pr @ Bargain Basement).
Sometimes I wear two pairs to magnify even more!
Just like Steve Fletcher the genius repair horologist on the Repair Shop program. It really does work!
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Genius Adam - Steve Fletcher already came up in conversation with Mrs about trying to see what I'm doing with the points. Trip to Poundland for more sets of el cheapo specs. Or might borrow Mrs' embroidery magnifier, has a bright light too, this sorta thing:

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Meanwhile, investigation delegated to a shade tree mechanic:


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The points set up, after I pulled the adjusting screws out:


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Could have called this a pointless picture, ahem, the advance mechanism:


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After I wiped it out - there was quite a bit of oil in there.

It rotates freely and appears to snap back when released but bearing in mind what has been said about tired springs I'll take a look at what can be replaced. Going to have a read at Pete Snidal's book and see what he has to say about points and advance mech.

I suppose it's fun to have a bike for tinkering and learning about stuff I haven't done before. There's no rush and there's two other bikes in the garage to make the best of this Summer weather.
 
Thank you, JP, I will watch the vid. Not too sure about the presenter's understanding - he says the spark occurs when the point close, I thought the opposite, but will watch to see the practical side of how and what he does.

The figure you quote of 0.8mm btdc is one I have become very familiar with. Perhaps I have over-thunk this but 0.8mm btdc seems a very small distance and hard to read accurately.

You put the tdc tool in through the plug hole, turn the engine - in gear and rotate back wheel - till the tool is at the top. Read the mark or make one with a pen. Hmm, yes but surely hard to locate exact tdc by this method. Then rotate the engine back till a second mark 0.8mm above is level with the edge of the hole. Again, I cannot see how to do this with any accuracy. It's a small distance and factors like parallax as you look at the spark plug hole & tool and even the thickness of the marks will make it very approximate. Which must surely add up to quite a few degrees of crankshaft rotation, especially in the tdc region?

0.8mm is supposed to be 10° btdc and full advance is 8.5mm or 32° btdc. I wish RE had put these marks on the rotor so I could check with a strobe. Would mean draining the primary but, hey.

Proper shade tree mechanics in India are said to time the ignition accurately enough using a bit of stick placed in the plug hole . . .

I'll give it a go tomorrow.
 
Checked the tappets - easy-peasy. One nut to remove the tappet cover:

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gives excellent access to the tappets:

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To check them, just take the hex part in your digits and twiddle, they should turn freely but not move up and down. Engine needs to be near tdc on compression, obviously. I adjusted them a few hundred miles ago and they're still fine. If the inlet valve was not closing, the tappet wouldn't turn. But as they are fine, that is not the cause of the backfiring.

Tried to establish tdc with the tool :

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and once again, not happy that I can do this. Apart from the scale being hard to read, it is difficult/impossible to make the engine stop at tdc. Bike in gear, turn the back wheel, you can make small increments until, just when you think is this the top, the engine rolls on a bit too far.

So I'm thinking, might need to pull off the cylinder head and the primary drive cover. Put a socket on the rotor to turn the engine under better control and see when the piston is 'up'. Then, take the opportunity to paint a mark on the stator, and marks on the rotor for tdc, 10° & 32° btdc. The marks can then be used for static timing or strobing.

Seems like I'm making too much of a meal out of setting the timing? Probably. But at least with this, uhm, antiquated design, the head is easy to remove with engine in frame, unlike our XSs.

Today, while thinking about that, remove and clean the carb. Expecting new points, condenser, advance springs from Hitchcocks. Oh, and a throttle cable - the one on the bike is a bit skanky, looks like the original Indian one and if so it's twenty years old. Hitchcocks supply a UK made, HD, nylon-lined replacement for £15. No expense spared, eh?
 
Thank you JP. I could use a dial gauge and I'm thinking about buying the brass one I mentioned yesterday.

The head gasket is copper so it should be OK if annealed. But a new one is £12 from Hitchcocks. Or £6 on ebay - probably from India which means waiting . . .

I actually have a plastic degree wheel, which I haven't used yet, because it would mean taking the primary cover off which is messy - there's no drain plug so it just floods. But if I take the head off, I'll open the primary both to turn the engine with a socket or spanner/wrench and to mark the positions on the rotor for future reference.

It just seems a lot of work to set the timing, though it would be less work next time. Apart from the messy bit.
 
Hmmm. Well, haven't pulled the head off yet.

Found that with the primary cover off and 1" socket of the crankshaft nut, it was a lot easier to turn and hold the engine. So with squinting at the tdc tool, fiddling to and fro, I kinda found a Top Dead Centre that is probably close enough.

Marked the rotor & stator with blobs of white paint:

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Marked tdc with a bit of masking tape laid over where I felt it was about right. Used a calculator to work out the offset for the others - easy as pi. Sorry.

Those are supposed to define 32°, 10° and tdc.

Approximately. Hell, the bloody marks must be about 1½° wide. But hopefully, can use these to set the timing now and in the future.
 
Approximately. Hell, the bloody marks must be about 1½° wide. But hopefully, can use these to set the timing now and in the future.
You could take a square block of something for a guide, rest it over your paint marks and use a scribe to scratch a well defined line into the paint blobs marks.
 
Checked the tappets - easy-peasy. One nut to remove the tappet cover, gives excellent access to the tappets:

I have never seen such an arrangement, where the tappets are adjusted down low on the motor by the pushrods.
It sure looks easy to get to!

it is difficult/impossible to make the engine stop at tdc. Bike in gear, turn the back wheel, you can make small increments until, just when you think is this the top, the engine rolls on a bit too far.

I have had that same problem at times, so I like to put a long breaker bar on it, it makes it easier to make small precise movements.
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Hmmm. Must be getting too fussy in me old age.

Playing about with the tdc tool, moving the engine to-and-fro, to drop the tool till it was just resting on the O-ring one way then the other. The mark I painted for top was not quite in the middle between those points.

Brought out the tdc tool I made a while back, see https://www.xs650.com/threads/2003-royal-enfield-500-deluxe.60842/post-745181

Obviously, the concern is, will it interfere with the valves? But the TDC tool doesn't so it oughta be alright.

Wiped the paint marks off. Turned the engine very gently till the tool stopped the piston, marked with a felt tip. Then turned backwards till it stopped again, another mark. Surprisingly, the marks are not very far apart - the tool is only just about long enough. Third mark halfway between - that should be tdc.


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I think I am making a meal out of this.

Never mind, might head out for a Sunday jaunt on Mis November after lunch.
 
Well, I went wrong somewhere along the line.

Using my newly established tdc, made further marks for static and advanced. Black indelible marker instead of paint this time. Used the static mark for my first attempt at setting points. Engine at tdc, set the points gap to 15 thou. Not too happy, 'coz the new points don't line up very straight - not so much they're out of parallel, more they're quite a bit more offset than I would like. However. Then used a test lamp to determine when the points opened. After a lot if fiddling, thought I had arranged it so they opened 10° btdc.

Decided to try it out. Primary cover back on and filled, tank back on, etcetera. Kicked the bike and third kick, engine started and immediately began to rev like a banshee. Pulled the decompressor, but still kept running so I had to switch the ignition off.

Wondered if fitting the new throttle cable I had left too little slack and the slide was being held too high? Checked and that was fine. Wound the throttle stop out some and kicked her over again. Same thing, revs heading for the sky. Shut it down again.

Out of ideas for now, another attempt tomorrow.
 
Oooh.......multiple changes in equipment; just helping your thoughts:

Removed slide to attach cable - maybe it's not in the bore correctly and not fully dropping. You checked freeplay.

Didn't completely follow points setting procedure (unfamiliar), but could be too advanced.

Still considering the dial gauge?

Thinking.....a light bulb may illuminate - at some point........
 
Removed slide to attach cable - maybe it's not in the bore correctly and not fully dropping. You checked freeplay.

Didn't completely follow points setting procedure (unfamiliar), but could be too advanced.

Still considering the dial gauge?

Thinking.....a light bulb may illuminate - at some point........
Thank you JP. I'm hoping for that light bulb moment too . . .

The way I checked the slide - ah, the upside of riding an anachronism, everything is just so accessible - simply pulled the filter off, used a mirror and had a look to see that the slide comes all the way down.

Most likely is that I got confussed and messed up on setting the timing. Maybe too advanced would lead to soaring revs?

Unfortunately, if I want to refer to those timing marks, the primary cover has gotta come off again, might try and keep the ATF this time. Yup, been thinking how I can usefully deploy that timing disc.

Bloody motorbikes . . .
 
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After a faint glimmer during the night, couldn't call it alight bulb moment, the theory I have been working on today is trapped throttle cable.

The return on the throttle seems a bit stiff. Could the cable be kinked or squashed under the tank, or as it passes through the nacelle?

You got to admit, it's a good theory. Took a look at the Unofficial Royal Enfield Community Forum and did a search on throttle cable routing. Bingo! Loads of results.

. . . bike has a hanging idle . . . you need to check the throttle cable routing . . . throttle is reluctant to close . . . likely the cable is being trapped under the tank tunnel . . . bike revving its' nuts off . . . need to re-route the cable ensuring no tight turns . . . etcetera

So that's what I've been doing today. Wasted hours trying to find an official cable routing, or just any diagram of where it should go. Nada. Never mind, let's just re-route the flaming thing so the throttle closes freely.

Done that. All back together. Kick the engine over. Three, four kicks, it starts. And the revs skyrocket. Ignition off.

Thinking cap on again.
 
Back to take another look today. Surely, the bike revving must be a carb/throttle cable issue? I can't believe setting the timing can cause that?

Mentioned above that I rerouted the cable - it seemed free and shutting the throttle, you could hear the slide hit bottom. But today, looking at it again:


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the area to look at is the brass adjuster at the top of the carb. The cable has jumped out, which will I imagine hold the slide up enough to cause the problem.

There should be a rubber cap - my bike had a perished vestige which did nowt.

Looking at tank off, re-route the cable again, maybe devise some jury rig with plastic tube & insulating tape, tank back on, try again . . .

Weather today, drizzle, so probably rather be in the garage anyway.
 
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