Done...........but won't run... :(

[SON]

Not a Maico man but I thought the 490 I rode was reed,
Must have been the 500,
You have to forgive me it was 30 years ago

[ola_martin]

There are quite a few reed conversions around, probably rarer with a original pistonport nowdays, but it was only on factorybikes back then I think.. I think reeds came stock on 490 in 83? Not sure myself.

[SON]

Back then a friend's brother was the Maico dealer,
We rode the same bush track, he allways had the latest Maicos

[3858]

Change the Spark plug even though it is new... Easy check...

[TM BILL]

There are quite a few reed conversions around, probably rarer with a original pistonport nowdays, but it was only on factorybikes back then I think.. I think reeds came stock on 490 in 83? Not sure myself.

We got some reed valve 490s in mid 81 at our local dealer A&S performance in the UK

[JohnnyO]

The 82 490 enduro came with a reed valve, it was still a twinshock bike and there are a few of those cylinders in use today.

[Mike52]

Hook up a battery powered strobe if you are wondering about the advance.
Does a 2/stroke need advance anyhow ?

[paul]

ignition
bing
wet plug after its running and stop must mean it getting fluid from some were .and were is it from cranckcase leaking or is it fuel because the ignition is faulty

if its a fault crank seal it would be leaning out when running/ sucking air
and if it sucking gear box oil you would think there was a new pope with the coloured smoke

[paul]

had a 400 aw that did that
use to start wouldn't rev
faulty ignition

[Montynut]

had a 400 aw that did that
use to start wouldn't rev
faulty ignition

I had one of my Motoplat ignitions do similar to this and it was a fault in the timing coil in the stator. Timing was good and stable at idle and low speed then just all over the place as revs increased. It caused at various times over heating, detonation, high speed miss and lack of power the problem slowly got worse. The motor never actually stopped but may as well have.

It was difficult to detect with a timing light as there was no consistency at all. It was found when Better Bikes put it on their test rig and ran at constant speed and mapped it.

[ola_martin]

Ok, thanks again.

It has new gasket and seals in the cases, so I'm at least hoping it's not there.
I have tried different setups on the carb, with no difference noted, so although the jetting may be off, I don't think that's the main issue.

Looks like I'm down to testing the ignition first.
And, it might be a 250 ignition, is that a problem? Just found our 490 and 250 run different ignitions?

[paul]

 same part number/ so im not sure never had a 250


                                               250      400       490

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