What have you done to your bike today?

[pepperami]

Managed to remove the chain guard from the swinging arm of Project Scrappy Hyosung.
Severe Corrosion meant it wasn’t straightforward, however the rattle gun won in the end .
Cleaned up the swinging arm ready for a lick of paint.
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I am the sum total of my own existence, what went before makes me who I am now!

[hellkat]

Soon it won't be hardly scrappy at all.
Paint, you say! Will it all be the same colour?
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Not nearly as interesting in real life.

[pepperami]

[Bloggsy]

Took it out for a fifty mile blast
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If It Aint broke Don't Fix It

[hellkat]

The GSX750 has now been MOT'd

Probably a bit of dicking around to do for the ULEZ thingy but that's got to wait til the DVLA get their finger out and send me the V5.



Tempted to have it delivered back to the Senior Consort's house so that I can ride it once I've taxed it, but ... maybe its better if I continue to be patient.
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Not nearly as interesting in real life.

[to v or not to v]

[Easy-X]

Put the correct map on the old fella's Harley. It's an improvement but not the silky smooth he's used to from the KZ1000, chalk and cheese obvs but I don't know how refined you can make a 650lb lump hammer

The T140 is continuing to be tricksy on the starting. The other day it was 2nd kick and today it's "fucking start ya bastard!" My money's on the coils being tired.
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[blurredman]

It's been a week since I put the ETZ250 back together.

Went for a quick test ride to-day to run it in a bit, and get out in the Sun.

But it was soon apparent that an old problem has come back to haunt me, namely the idle gets a bit lumpy and then sometimes the bike stalls and then runs backwards all on it's own. Ughh.. It was funny in 2017, but not now.

I put many hours into the issue years ago including going as far as rebuilding the engine with a different crankshaft but nothing worked. It still ran backwards- so in frustration I bought an electronic ignition unit, but after a while I got bored of that, and it was still running backwards anyway- I put the points back on and it NEVER EVER ran backwards again until now...
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CBT: 12/06/10, Theory: 22/09/10, Module 1: 09/11/10, Module 2: 19/01/11
Past: 1991 Honda CG125BR-J, 1992 (1980) Honda XL125S, 1996 Kawasaki GPZ500S.
Current: 1981 Honda CX500B - 91k, 1987 MZ ETZ250 (bored to 295cc) - 38k, 1990 MZ ETZ251 - 49k, 1979 Suzuki TS185ER - 9k, 1973 MZ ES250/2 - 17k.

[A100man]

[Easy-X]

You can fiddle with the timing, retard it a little. Have you raised the compression at all? e.g. Thinner gaskets.
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[blurredman]

The timing is on point, I even tried my tests on fully retarded and it still ran backwards, the problem presumably is some sort of chatter, that occurs around the TDC range, one which was eliminated in 2018 when I re-installed standard setup, quite by accident. The reason the electronic ignition I had tried allowed backwards running was because design (two magnets on the rotor, about 45 degrees from eachother). I later sold that. Useless.


Gaskets are the same (aluminium) ones I had on before I took the crankshaft out to replace the main bearings. Squish band is nice.



One thought perhaps is that I set the points gap a little bit more than 0.3mm (maybe 0.4 which is permissible according to the manual).


Chatter is more evident in contact breakers which don't open very far. It's quite a fine running bike when actually 'riding'.

Equally so, it's worth going over the cam with some polish maybe. Plus potentially, I know there is also a washer between the cam and the stator rotor, removing that washer which measures about 1-1.5mm thick can allow the shoe to ride on a slightly different, and maybe less rugged surface of the cam - so this may or may not help too. There isn't any rust on the cam and on quick inspection yesterday it didn't seem excessively scored- I mean, the contact breaker shoe is only plastic after all.

I don't have a spare cam, the one I do have is for 6v models. The spare that I did have was stolen outside the DAF museum in Eindhoven in 2017.
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CBT: 12/06/10, Theory: 22/09/10, Module 1: 09/11/10, Module 2: 19/01/11
Past: 1991 Honda CG125BR-J, 1992 (1980) Honda XL125S, 1996 Kawasaki GPZ500S.
Current: 1981 Honda CX500B - 91k, 1987 MZ ETZ250 (bored to 295cc) - 38k, 1990 MZ ETZ251 - 49k, 1979 Suzuki TS185ER - 9k, 1973 MZ ES250/2 - 17k.

[Easy-X]

Only if you have the spare bits kicking about but if you could drop the compression with a slightly thicker gasket I'd be interested if it made a difference.
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[blurredman]

All I tried last night didn't work.

When the bike did it last in '17/'18, I did all sorts as mentioned, rebuilt engine with different crankshaft (still the same one it has now), I put on standar piston and barrel with standard spec squish/head gasket thickness, did everything I could, and it still ran backwards. Which as I say is when I gave up and put a crappy electronic ignition on which also gave allowance of backwards running. I removed it months later and to put the points back on just out of curiosity and it was never and issue again until sunday. Very curious. The annoying thing is of course, I never got a proper resolution- it just worked, when before it didn't.


I'm going to swap ignition systems between my 251 and the 250. Would be interesting to see if 251 runs backwards. That currently has electronic ignition, so putting that on the 250 would also be interesting to see what happens.
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CBT: 12/06/10, Theory: 22/09/10, Module 1: 09/11/10, Module 2: 19/01/11
Past: 1991 Honda CG125BR-J, 1992 (1980) Honda XL125S, 1996 Kawasaki GPZ500S.
Current: 1981 Honda CX500B - 91k, 1987 MZ ETZ250 (bored to 295cc) - 38k, 1990 MZ ETZ251 - 49k, 1979 Suzuki TS185ER - 9k, 1973 MZ ES250/2 - 17k.

[Easy-X]

I wish you all the luck in the world but inherently 2-stroke is a reversible system. It's only continued momentum that keeps it going in a particular direction. Timing-wise, advance turns into retard, retard to advance so really all you're affecting is the quality of the running and as this happens when the engine's technically stopped, as you've discovered, timing can only discourage rather than fix the problem. With enough experimentation you might find a sweet spot with the timing where it goes backwards a lot and... errr... not do that

A few people [on the Interwebs] have alluded to compression affecting things but I suspect it only vaguely alters the frequency of occurrence. About the only practical thing I can think of that won't exactly fix the issue but might head off the opportunity is to raise the idle speed so you're less likely to stall
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[blurredman]

Yes, it's true- there are still things I can look at, timing aside- you're right about compression, and I am still going to be taking the head off and checking stuff. First problem I potentially did- I never checked total height of piston in relation to the old, nor even gudgeon pin reference etc. I need to clarify things on those basic levels again first perhaps.

The standard compression is 10ish to 1. But i've had 12ish to 1 before now and not had this problem occur.


I had a thought- there's no point putting on the EI from the 251, if that also would spark with the engine rotating reversely. I can make a quick and easy test on that by just putting it in gear with the spark plug out (in cap) and seeing if I get spark rotating the back wheel, backwards. I've tried it with other electronic ignitions and they have allowed it, but never with this (no need to), so will be interesting for me to see. After all, it's typically just a magnet so any sweep in any direction normally would give the signal and give spark. But some EI's might be more clever. Anyway.
____________________
CBT: 12/06/10, Theory: 22/09/10, Module 1: 09/11/10, Module 2: 19/01/11
Past: 1991 Honda CG125BR-J, 1992 (1980) Honda XL125S, 1996 Kawasaki GPZ500S.
Current: 1981 Honda CX500B - 91k, 1987 MZ ETZ250 (bored to 295cc) - 38k, 1990 MZ ETZ251 - 49k, 1979 Suzuki TS185ER - 9k, 1973 MZ ES250/2 - 17k.

[Easy-X]

I don't see how the EI can know the direction unless there's some asymmetrical arrangement of pickups that could make the guessing easier
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[hellkat]

If they (the DVLA?) let you pass an MOT with a short VIN then how come they won't then let you tax it and change it with your name/address on the V-bloody-62. Twats.
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Not nearly as interesting in real life.

[DrSnoosnoo]

Tightened its chain. I've got quite spoiled with single sided swingarm chain adjustments.

Looking one side to the next to try and keep them even ... I need my abba skylift back in action, balls to crawling on the floor again.
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I'm Sam; Northern, Ginger, Lover
Did have: '95 ZZR600 '83 CG125 '97 ZZR1100 '15 Hypermotard 821 SP Do Have: '10 ZX10R

[blurredman]

[Easy-X]

Just as an aside here's an example of how you'd sense direction with an optical wheel:

https://www.labbookpages.co.uk/circuits/wheelEncoder.html

tl;dr two sensors and you arrange things so the pulse overlaps hint at the direction.

Anyhoo, you can fiddle with the timing to make reversibility slightly easier or harder but probably better off chasing down why the engine stalls and fix that.
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[Easy-X]

All of a sudden the old fella's KZ1000 won't start or, more accurately, the starter motor won't turn as it kicks over fine.

Started going over it with a multimeter only to discover the first one out the drawer's a dud Took the switch assembly apart and gave it a clean, still wouldn't start, turns out it's the clutch lever safety switch.
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[Zen Dog]

Took the rear wheel of the VFR750 for powder coating. £60. Should be ready Monday or Tuesday apparently. The guy does car wheels mainly, but because of the single sided nature of the VFR the wheel has no disk posts, bearing seats or anything to worry about, it just needs masking in the same place as a car wheel, so I'm hoping it should be ok. I've asked him to have a look for any cracks while he's sandblasting the wheel too, it is pretty flaky and 27 years old.
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Current - '94 VFR750FR, '00 VFR800FI Previous - '10 Street Triple R, '92 MZ ETZ301, '05 TTR250, NSR125R, KMX125, "Honda" Win (chinese copy of an old Honda design with a C90 engine)
My bike trip around S.E. Asia 2010/2011

[hellkat]

Had a conversation with the Suzuki-fixing man today

Its got something wrong with something something number 2, and he's sonically cleaned it but they stripped it down and found a chunk out of an O ring (does that sound right?) - so they replaced that and then they tested it, something to do with number 1 and 4, and then number 2 and 3, and it worked fine, but number 2 was doing something funky still ... I got a bit lost at that point.

But apparently we've agreed for him to strip it back down, have a look if he can find stuck gunk, and then maybe if necessary give it a second ultrasound, and then reconsider.

So yeah. I might ring the Harley-fixing guy tomorrow and find out what's the latest news* on that, just to cheer myself up

*(none, I assume as he hasnt rung me in a month )
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Not nearly as interesting in real life.

[A100man]

[recman]