(TS150) It came from the 1970s...

[MichaelTorre]

Do a compression test. It does sound "soft".

Hope I am wrong.
M-

[Agronski]

Don't think it's loss of compression - the back-force from the kickstart is pretty serious, and don't think it's timing, either since it's set to about 2.5mm BTDC, and besides, TS now runs beautifully. I took it out for a spin, knocked it up and down the gears a few times and 1) neutral light came back on when it was in neutral (has previously been permanently off) and 2) adjustments made to the clutch worm and cable now gives a smooth, even take-off with nice power and the clutch lever also no longer 'weighs' a tonne.

Still, when cold the clutch seems a lot more reluctant to fully let go of the engine - takes a few minutes idling (now at about 1200 or less) to warm up and the clutch to fully disengage when the lever is all the way in.

So, I'm happy for now - TS runs very nicely, if possibly a bit fuel-hungry - I've only been putting in about half a litre in at a time for test-runs, but that goes pretty quick - generally less than 10 miles. I'm pretty sure the choke is sealing properly, and the carb is pretty much stock, but I wonder if I'm pissing fuel from the overflow. I will check the float needle later, just in case. BR7HS plug is lovely caramel-brown, so not running too rich.

But for now - is there any mechanical reason for the clutch to take so long to 'warm up'? Springs are good, plates look okay from the outside (but are probably 1970s originals, so who knows) and the cable, arm, worm and so forth all seem sound and respond to adjustments. Any why would the neutral light come and go?
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[DAVID THOMPSON]

i had a yamaha 305 ym1 1966 to about 1971 it was not very easy on the gas fumes..
a good week end run would get right into my pocket book big time if you wound it's tail
dave

[therealche]

But for now - is there any mechanical reason for the clutch to take so long to 'warm up'? Springs are good, plates look okay from the outside (but are probably 1970s originals, so who knows) and the cable, arm, worm and so forth all seem sound and respond to adjustments. Any why would the neutral light come and go?
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I reckon the plates are gummy. If you feel like stripping it all out, washing them in petrol, and giving a good scrub it will probably clear up stright away. Otherwise just using the bike will clean them up after a while. Happens when they have been sitting in old oil for ages.

And the neutral switch may need adjusting, of may just be a bit dirty. Its all covered in the manual

[pmorris4562]

Have you checked the ignition timing? And what about the air filter.... if its clogged it will strangle the engine

And ditto a gummed up exhaust.

[Agronski]

Air filter is brand new and clean, exhaust is brand new and has had less than 10 miles of 33:1 mix burned through it (now running 50:1) so I'm pretty sure it's not coked up. Think realache is probably right about the old plates, because it knocks loose after running for a time, and after it's warm she runs just fine - plenty of power, no obvious slip, no four-stroking or bogging. Will put a few decent miles on it, maybe a proper plug chop and/or some miles on the autobahn, then do another oil change if it hasn't cleared completely.

Will try and adjust the neutral switch soon - will have to dig through that 70's sludge to get at it, though. Bleuch.
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[breakwellmz]

But for now - is there any mechanical reason for the clutch to take so long to 'warm up'? Springs are good, plates look okay from the outside (but are probably 1970s originals, so who knows) and the cable, arm, worm and so forth all seem sound and respond to adjustments. Any why would the neutral light come and go?
___

I reckon the plates are gummy. If you feel like stripping it all out, washing them in petrol, and giving a good scrub it will probably clear up stright away. Otherwise just using the bike will clean them up after a while. Happens when they have been sitting in old oil for ages.

And the neutral switch may need adjusting, of may just be a bit dirty. Its all covered in the manual

+1

Like a lot of small basic two strikes like these-No Reed vavle etc,EVEN when they are sorted,they are not like long periods on tick-over or a lot of slow speed running.

The number of times in the past i have thrashed two strokes down the local bit of dual carriageway on full throttle to`clear the pipes`