Maico 490 H2o

[shelpi]

Gday Guru's Ive got 2 conflicting years when the first watercooled came out
1) my thoughts 1985 GS(490) 500 and the 250 in 1984
2) some sites are saying GS500 1984? Mstar or are they only stock in preperation for the release of the 1985 model to the USA as is the case with the 1985 Maico sidecar

Ohh yer what year is a EC 500 (490) engine? I bought a what looks like a 1985 on donk in all regards has maico on the barrel and clutch cover, bore x stroke 86.5 x 83
SEM 12v electrics/lights
is it a 1985/86 blue Mstar? googled EC 500 11...  but nothing

[Tim754]

Engine number (prefix only needed) thanks Pete, but... I am pretty certain my records run out late 1983, when I find them.    Found Them    These notes may have come from Peter Drakeford a squillion years ago. Tim754

[evo550]

1984 250's and 1985 500's

[shelpi]

 I tried looking for that list Tim but could'nt find it so thanks, h2o 84 250 85 500 I cant believe how much mixed up info is out there, but still cant work out what year a EC 500 watercooled is, must be European as I did buy it from Germany

[evo550]

What's an EC ?

[Maicoman]

1984 SC 250 watercooled
1984 SC500 (still only 490cc) Aircooled
1985 Maico GM 250 (MX version) watercooled, called M Star in the US & some other countries.
1985 Maico GM 500 (MX version) watercooled, called M Star in the US "    "         "
1985 Maico GME 250 (Enduro version) watercooled, called M Star in the US "      "      "
1985 Maico GME 500 (Enduro version) watercooled, called M Star in the US "     "       "

The old aircooled engine from 1984 was still available as an option for 1985 & 86.

This is the 1985 lineup







This is the 1986 lineup

[shelpi]

Thanks Maico man, good work, after all that I still dont know what EC on the engine number is but at a guess I'd say around 1985/86 ish  Europe GME500 cos its got SEM lighting/ igniton external flywheel
Hey will the 610cc Zylider go straight on the 500 liquid 86.5 bore x 83mm stoke and could you wack in a 610 sleeve into a 490 air cooled jug?

[shelpi]

found an article from VMX news posted 20 sept 2010 a good read and goes on from the Mstar to when Lorenz Merkle picked up the peices and made the baby blue in 1987 (I found blue paint rub marks on mine, probobaly when removeing it) in 1988 the 500 received the power valve S.E.E.S (slide engage exhaust system) first used on the 250 in 1986, and yep mine has the S.E.E.S so itsa 1988 baby blue, it say Merkle increased the motor to 610cc in the 80's so at the moment asume the 500 and 610 use the 83mm stroke. as stated almost a decade later in 1992 the 490 would finally make the jump to 500cc Merkle had the stroke increased from 83mm to 85mm uping the displacemnt from 488cc to 499cc
in1985 the engine to frame bolt pattern changed and remain the same to this day.
so for me the E is for eduro and the C well I still dont know, so thanks for your help and one day I might know what Im talking about

[shelpi]

ahh Yess, my wife just got home with some mail and The Maico 1986 betriebsanleitung was in it, Yep the owners manual for the
GM STAR 250
GM STAR 500
GM STAR 250E
GM STAR 500E
 
GM500 type 368/ 86
GM250 type 367/ 86
and straight away can see the GM500 has S.E.E.S  and its in german and english, charts, parts numbers and can compare against the 1983/84 chart from Paul, and its got  Gebr. Maisch
Zweiradhandel- Produktions GmbH
Nagolder Strabe
7403 Ammerbuch-Pfaffigen  on the front so  itsa ridgy didge 

[shelpi]

Maico 1982
MC 490 Type 354/ 82  with reed valve but old primary drive chain job
MC 250 Type 353/ 82

Maico 1983
MC 490 Type 362/ 83 The new donk
MC 250 Type 361/ 83

Maico 1984   364
SC 500 Type / 84  engine  shown as type 362 via maicomx.net same donk
SC 250 Type / 84  1st liquid cool
                     363 not proven yet 
Maico 1985
GM 500 Type 366/ 85 1st liquid cool
GM 250 Type 365/ 85

Maico 1986
GM 500 Type 368/ 86 1st S.E.E.S power valvle
GM 250 Type 367/ 86

[shelpi]

yep liquid 610cc zylinder (Nikasil) from 83mm stroke will fit all the 490/500cc and 440' liquid cooled 83mm stroke donks
and on that note 1983/84 air cooled 490/500 488cc 86.5mm zyliders will fit all liquid cooled 83mm stroke later model engines, but cannot put liquid cooled on the 1983/84 air cooled unless machine cases to allow skirt in, oh and primary side of the crank needs slit at the end to drive the pump