SERVICE BULLETIN
Inepection and AdJuetment of the 250, 400, 450, and 501 Tranemieeion
Before taking the engine apart it ie recommended to clean the engine.
Try to avoid direct steel hammer hits on the parts. Split the engine carefully
and take out the tranemiseion.
Check for wear:
dog pinion gear, sliding geare, shifting forks,
cam assembly, guide bush.
Check for excess eide play:
between retainer ring and dog pinion
gear.
ATTENTION:
Brakeage of transmiseions can be caused by improper chain alignment.
(Chain jumps out of sprocket and locks the engine.)
On 250, 400, 501 Square barrel 'T' or old tranemisslons check the mainshaft or
bronte bush and sleeve pinion for free rotation. Before assembling or in.erting
into the counterehaft it ehou1d be lubricated with anti-friction 1ub.
Cleaning the tranemiesion parts and gears is advisable for proper adjuetment ••
1.
Ineert the geare and with crankcaee gasket close the engine houeings. The
layshaft clearance should be checked after fixing the engine ca.e. together
and tightened with three middle engine screws. The engine ca.es are ea.y to
work without the crankehaft. Tighten the countershaft nut. The inspection
of the tranemission gears is easier to check with the engine case. lying
clutch side up.
2.
Leave the gear engaged in nautra1 poeition and fix the dial indicator (.hovn
in fig. #2) on the caee. With the half of a bended hook the end .hould be
inaerted into the hole (fig. #2B), lifting the third gear in the 1ayshaft
find the L/Shaft clearance. The layshaft clearance should be 0.10
DID
(.004")
to 0.20
DID
(.008"). If it 1a lI'Drethan that, ehims ehou1d be added to
obtain the clearance.
SERVICE BULLETIN
Inepection and AdJuetment of the 250, 400, 450, and 501 Tranemieeion
Before taking the engine apart it ie recommended to clean the engine.
Try to avoid direct steel hammer hits on the parts. Split the engine carefully
and take out the tranemiseion.
Check for wear:
dog pinion gear, sliding geare, shifting forks,
cam assembly, guide bush.
Check for excess eide play:
between retainer ring and dog pinion
gear.
ATTENTION:
Brakeage of transmiseions can be caused by improper chain alignment.
(Chain jumps out of sprocket and locks the engine.)
On 250, 400, 501 Square barrel 'T' or old tranemisslons check the mainshaft or
bronte bush and sleeve pinion for free rotation. Before assembling or in.erting
into the counterehaft it ehou1d be lubricated with anti-friction 1ub.
Cleaning the tranemiesion parts and gears is advisable for proper adjuetment ••
1.
Ineert the geare and with crankcaee gasket close the engine houeings. The
layshaft clearance should be checked after fixing the engine ca.e. together
and tightened with three middle engine screws. The engine ca.es are ea.y to
work without the crankehaft. Tighten the countershaft nut. The inspection
of the tranemission gears is easier to check with the engine case. lying
clutch side up.
2.
Leave the gear engaged in nautra1 poeition and fix the dial indicator (.hovn
in fig. #2) on the caee. With the half of a bended hook the end .hould be
inaerted into the hole (fig. #2B), lifting the third gear in the 1ayshaft
find the L/Shaft clearance. The layshaft clearance should be 0.10
DID
(.004")
to 0.20
DID
(.008"). If it 1a lI'Drethan that, ehims ehou1d be added to
obtain the clearance.
Maico 72-74.5 Radial Manaual
www.maicowerk.com
Courtesy of [email protected]
