thnks to all posters
looks like i'll just have to continue shopping around
just as well U.K. shipping is cheapest as they hold much of the good stuff. cliff

You suppose that maybe that tire wouldn't have crept round the rim enough to tear the tube if rim locks had been installed?

I am running a #3 slide, air valve was 2 turns out, jets and all replaceable parts are brand new from AMAL, needle was on 3rd notch. I lowered the needle to the 2nd notch and turned the air screw 1 1/2 turns out from seated. I fired the bike up, with it on the center stand the bike stumbles off of idle now but revs past smooth all the way up once it gets past the stumble. I didn't get to ride it as its pretty late, and tomorrow its calling for rain all day so wont get to do load testing until Friday at best.

It's been a while, but are there new slides available for the 689 carb? I havent looked in a few years but they were impossible to find back then. If not, would stock pea shooters work better for me? I just got these pipes cheap and they look cool, not that the peashooters don't look cool.

Hey Gavin, fill oil tank just before startup, pulled the plugs, kick over with key off for a good minute then got ready to fire it up, slow to start, gave it some starter fluid then it fired up. But oil light stayed on and throttle stuck, tapped the carb body to free slide motor making a racket turn off. Replaced the oil pressure relief valve, fixed carb throttle and fired it up again. Oil light went out, but still made a racket, put it in gear moved, it a bit, worked clutch, it was ok. checked oil flow back to tank kind of a fast dribble, shut it down. And here I sit with this great looking bike and the more I thing about racket noise, it sounds like starving for oil with no real tell tale sign of where the noise is coming from, will check the sump for gold tomorrow. How fast should the oil return flow be from the tube in the tank?

there's way too much fiddling on nitromethane. blending the fuel, starting on alcohol, and then trying to use up the nitro without hydraulic locking the motor. alp has mentioned at least once melting his pistons because he forgot to re-jet. in the end, it just doesn't interest me. bottles and nitro will let you go faster, sure, but if just going faster was the point i'd be in the market for a ZX-14 and not messing with old british twins.

but you might experiment with oxygenated fuel.

This stuff has been doing wonders for me.... Spray it on and let it sit , but keep it wet..... Mist Sprayer is good for that.... Then garden hose clean . Rust is gone with no scrubbing..... Unless its really bad then several applications and a little scrubbing will do the trick

https://www.rustoleum.com/product-c...o/removers-and-chemicals/rust-dissolver/

Thanks trev. I'll get something to you this afternoon.

A person doesn't have to time a magneto very often, but when they do they have to spend quite a while fussing with it. So, I took the time to make it easier on the Ariel in the future. With luck, I won't have to worry about retiming the magneto on the rally but, if I do, now it should be a lot faster.

The first photograph shows I found TDC with both valves closed and punched a dot near the top of the end of the camshaft that I then filled with white paint to make it easier to see (it looks yellowish in the photograph). I then installed the sprocket with one tooth pointing vertically, marked TDC on it in white as well as 40o BTDC in gold. All of this eliminates trying to figure out in a dark motel parking lot if the valves are open or not, which way the shaft rotates, and which is BTDC and which is ATDC. For those of you who are worried about the lack of a degree wheel, keep reading.

The next photograph shows that I set the magneto so the points were just opening and punched a line into the end of the shaft that I then filled with gold paint. The photograph also shows the adjustable sprocket I bought from someone in Australia (whose name escapes me at the moment) with the cap screws holding it in the center of the adjusting range. In this position the sprocket has ~30o of adjustment toward advanced or retarded. In the process described below the lines I engraved every 4o (engine) aren't needed.

The third photograph is the timing stick I showed previously that I've now modified to have scratch marks at 34o and 41o in addition to the ledges at 36.2o (7/16" BTDC) and 38.9 o (1/2" BTDC) corresponding to the two values given in Ariel literature. This allows me to directly see how far off I am if I slightly over- or under-shoot one of the ledges when rotating the engine, and decide whether that position is good enough to use.

I'll add here that I measured the total advance range of the magneto to be 53o engine. This explains why the engine starts so nicely when I have the lever set halfway since the timing is ~39o - 26.5o = ~12.5o.

With the above in mind, the procedure for timing is to set the engine so the sprocket is at the 40o mark. Then, set the magneto shaft so the line is vertical and install the sprocket with the teeth locked in the central position. Next, use the timing stick and rear wheel to tweak the engine to precisely the 39 o position. Finally, with the inductance meter connected across the points loosen the three cap screws and use a spanner on the magneto nut to controllably rotate the shaft to find where the points open. Lock the three screws and double-check the result by watching the inductance meter and timing stick as the engine is rotated using the rear wheel.

The "only" thing having marks on the two shafts does is make the process a lot faster, as well as eliminates the possibility of accidentally timing the engine ATDC or on the exhaust stroke. Not coincidentally, after timing the engine as above, and setting the magneto lever in the halfway position, it started on the first kick.

As a final note, I can "only" set the timing to within ~1o using the timing stick whereas I could do twice that good with a degree wheel. However, given that it's not clear whether the "correct" value for modern fuel is 36o, 39o , or some other value, accuracy greater than ~1o isn't called for.

works o art

I think so. We will see.