[Blaqkfox]

And that’s very interesting Adrian! Could I not simply measure the degree off the flywheel while the bike isn’t running?

I also saw a thing that looks like a relay on my bike but found it on hitchcocks listed as a “spark delay unit”. I’m assuming this is factory? But the listing discription made it sound aftermarket. In any case, I have one on my bike and I’m wondering if that could be the issue…

[Adrian II]

The spark delay unit was a bit of an afterthought to try and preserve the electric start sprag clutch, early examples of which started making the dreaded bang-crunch noises quite early on. It would allow the electric starter motor and extra second or two to get the crankshaft spinning properly before allowing the ignition to spark. The initial voltage drop caused by the starter motor flashing up could affect the timing of the TCI's electronic auto-advance momentarily, thus certainly used to be a thing on Norton Mk3 Commandos fitted with certain aftermarket electronic ignitions, which could wreck their sprag clutches with a misfire. In this context it's also vital to have a really healthy AGM battery with plenty of CCA to spin the crank well.

AFAIK the spark delay unit doesn't affect the ignition timing itself, it's to stop the TCI having a momentary fit, and I wouldn't have thought it's the cause of any overheating. I understand the later GREEN TCI unit (early ones were black) has the spark delay built in.

The other thing you can try is an alternative TCI box, the slightly bulkier one off a GS 125 Suzuki will work well with the Electra-X. These have a greater advance and retard range, I used an OEM one successfully for a number of years, though tooseevee tried a pattern item off eBay on his AVL Classic, and this never really worked. Fortunately I don't think they're horribly expensive, if you want to experiment.

A.

[Paul W]

Bearing in mind that the AVL engine is designed to run lean, that plug probably isn't too far off correct. The best answer is to get a lambda probe up the pipe and check it properly.

[Blaqkfox]

Adrian you are a wealth of knowledge bud! I think I actually already have the green TCI unit! There’s a big green box under my seat next to the regulator/rectifier. Which is confusing since I also apparently have the black box on the side of the battery that is the spark delay unit… so is my spark being extra delayed?

[Blaqkfox]

Bearing in mind that the AVL engine is designed to run lean, that plug probably isn't too far off correct. The best answer is to get a lambda probe up the pipe and check it properly.

I have wondered about just installing a bung in the exhaust for a air/fuel ratio gauge. Since it’s a single cylinder I think it would make tuning very easy.

[Adrian II]

It has been done, there's a bit of a write-up in the previous issue of "The Gun", the magazine of the UK Royal Enfield Owners' club. I think the guy welded a M18x1.5mm boss onto the Electra-X for the lambda sensor downpipe somewhere near the top and fitted a gauge mounted on the handlebars, although he was using a PWK34 carb instead of the original.

A.

[Blaqkfox]

So I ended up removing the shim we had under the needle.

Feels better coming out of 1st from a stop now.

Also accelerates noticeably faster through midrange (as expected)

Top speed has also increased by about 4mph (unexpectedly because the main jet is still the 118, granted its about 20 degrees colder today too)

The header however continues to turn all sorts or purple and blue and gold...







Im starting to question having the larger main jet...

everything is stock on this bike except for deleting the PAV system and pulling that baffle out of the header.... so im wondering if a larger jet is even necessary after removing the baffle in the header pipe?

perhaps it is and ive just gone too large with it? The spark plug doesnt appear to be too rich. in fact it almost looks like im somehow running both too rich and too lean??? just guessing by the super white ceramic, but then the "a little too black" sooty ring around the base here...



I also notice the ground strap is burned a little more than halfway back so this plug might be a bit hot. supposedly its an equivalent to the B9ES NGK (I ruined that NGK when I put the 118 in it and it was super rich, hence why I pulled the baffle out, then put this autolite plug in and it seemed happy but still slightly rich, hence removing the shim we had on the needle now).

So idk im thinking I should just put the 110 back in but now im not sure with the baffle removed if that'll be too lean... maybe like a 115 would be better? I need to order a jet kit...

at any rate, this running slightly rich and at higher rpms for long periods of time is the only thing I can think of why my pipes are turning color, but I mean they are super BLUE.

[Adrian II]

Running leaner = running hotter.



I apologize if I repeat myself, free breathing exhausts need jetting UP to compensate. Yours obviously isn't totally free while you still have the stock muffler on, but clearing the lean-burn stuff out of the downpipe will have had some effect. There are stories of owners of 70's(?) Triumph Bonnevilles back in the day replacing their by then already more restrictive mufflers with open ones, but failing to jet up and wondering why the engine had overheated and seized up. Having an alloy cylinder barrel will have helped your engine.

That picture was around Spring 2006, my son grew up sadly without digging motorcycles of any description. That was a Hitchcocks' un-restricted downpipe and Goldie (pretend) muffler, Dell'Orto PHF32 carb on a 130 main jet on my old Electra-X, in case you were wondering...

A.

[Blaqkfox]

It is up jetted to a 118.

It acts like it runs rich at WOT.

Pilot jet is still the 15 though.

I read the thread on here labeled “successful carb tuning” where they were running a 120 and a 17.5 on the bs29 but they also drilled out the holes in the slide and had a full exhaust and intake.

Idk I just need to order a jet kit and play around with it at this point. This is my first ever attempt at re-jetting a carb so I have no idea what I’m doing really lmao. All I know is I’m supposed to “go up a size” but what’s a size? 2? 5? 10? I’m sure it’s application specific and just requires playing around with it to find that sweet spot. Which would be a lot easier if my plug was easier to read and I was more versed in listening to the sound of the exhaust and rpms to know what’s going on. This plug just trips me up being the ceramic tip stays white looking lean but the base stays sooty looking rich. So that confuses the hell out of me.

[Adrian II]

The carb tuning article is actually TWO articles copied and pasted into a single document. The stuff about the jets was written by a UK Electra-X owner, while the part about opening out the holes in the CV slide was written by a guy in India for the BS29 carb on an A500 Machismo, which was the Indian home market version of the lean burn 500, sort of a halfway house between the Electra-X and the USA market only 500 AVL Classic.

AFAIK the author of the Indian article had modified the slide only, while the UK Bulleteer didn't carry out the Indian modifiaction. I'd have to have another read of the whole thing. Somewhere there's a very good picture of spark plug comparisons showing every conceivable shade of sooty black through brown to a that's-what-you're-after beige, right through to bleached white horribly lean. If I remember I'll see if I can find it an post a link.

If you're really not sure what you're doing, do get or maybe HIRE the Gunson color-tune kit as it will SHOW you what sort of mixture you're running at different revs.

A.

[Paul W]

That spark plug looks OK to me, or perhaps very slightly weak. The “spot on mixture” look is where the side electrode has a trace of soot just before it joins the main body.

But your bike is a lean burn anyway. With modern fuel you can expect to see carbon black on the “rim” of the main body when the setting is good.

As far as your exhaust blueing is concerned, I think it is a double skinned pipe and so heat is carried in the inner pipe to where it ends, just ahead of the silencer, then the outer pipe sees that heat.

[Blaqkfox]

The color change seems to have subsided for now. The bike feels like its probably still too rich on the main jet but im not positive.

If I only have the baffle in the header removed should I be using stock jetting still? It doesnt open things up that much I feel like.

[tooseevee]

If I only have the baffle in the header removed should I be using stock jetting still? It doesnt open things up that much I feel like.

           Removing that hot-tube opens it up A Lot. It's very restrictive; that's its job, to restrict exhaust & make the whole exhaust path hotter.

           And how can you tell if it's bluer or not bluer when it's already all blue?

[Blaqkfox]

I made a video explaining the situation

https://youtu.be/6sCh5kRLJlo

[Blaqkfox]

So today I switched to a 17.5 pilot jet and a 120 main jet. To recap all I've done is delete the baffle in the header pipe.

The bike was hard to start until I found the right fuel screw setting of course.

I dialed things in, I found it was much easier to tune with the idle set pretty high, I could actually hear the revs increase then. And once it was in the right area I let it idle down and then I could distinguish the rev increase and decrease finally.

I too rich now though...





Granted I am about to buy a different exhaust since this one is all blue now. How do you tune it in without turning the new exhaust blue?

I think I like the sound of the Goldstar that H's sells the best. I might need a high flow K&N too yeah? I guess well see if it leans out a little with a less restrictive silencer in the mix next.