Post by wayne on Jul 20, 2015 19:23:24 GMT -5
From the Factory: "New Model Technical Bulletin". I have copied text verbatim or paraphrased the original. Notes in italics are my own comments.
Changes in the A model:
Visual:
Black tank and sidecovers (blue option shown in A model brochure but apparently never produced), New instrument cluster (similar to but not identical to GT750A, most significant difference to GT are idiot lights in the tacho housing and the speedo doesn't read as high in the mph version (not sure about kph), New headlamp housing, new tail lamp (both of these similar but according to part numbers, not identical to GT750A), Turn signals (fronts are similar but not identical to GT750A numbers, rears are identical by part number), Head lamp stays (near identical to GT750A, once again, part number is slightly different).
Engine:
Reduced oil consumption accomplished by modifying the oil sealing mechanism and also by machining the critical parts of this mechanism to closer tolerances (allegedly reduces sump consumption to 1 litre per 1,600 klm).
Carburetor:
Main jet down to 87.5 from 90
Port valve timing to 35 degrees from 41
Accelerating pump timing down to 28 degrees from 30.
Accelerating pump capacity increased to 0.7 cc from 0.5 cc
Accelerating pump spring change (yellow in colour compared to stainless wire). Less subject to weakening.
(The setup changes were covered in the Suzuki Bulletins, #8 and #9)
Heat insulating gaskets at both Carby to inlet manifold and between manifold and engine. For the stud bolts securing the intake manifold, use bolts 5mm longer than those hitherto used. (This note about the studs is in the part interchangeability section but I assume that bikes that left the factory fitted with the insulators fitted already had 5mm longer stud bolts).
Marks on the choke mechanism allow unloader calibration without a gauge.
Spark Plug:
From NGK A9EFVP to NGK A9EFP (Gold to Palladium)
Contact Breaker:
Reversion to single points. Vacuum take off on inlet manifold plugged with rubber cap, B points removed, Speed relay removed, RPM sensor no longer in Tacho, Vacuum switch removed. (I would speculate that if you still had the vacuum switch etc under the tank, you have a bike that probably left the factory as an "M" and had the "new model" change over done at the dealership).
Ignition timing is given as 5 degrees (this is not given in the manual as a specific A model change but is mentioned. It's noted in the Bulletins as a general change along with the valve timing alterations etc).
Drive Chain:
New style O ring chain.
Chain oiler eliminated.
Electrical:
Minor changes in the wiring diagram.
The parts book shows that there is also a physical difference between the front and rear halves of the rear fender between the M and A that is not mentioned in the above booklet. They mount to the frame and each other in a slightly different way
Changes in the A model:
Visual:
Black tank and sidecovers (blue option shown in A model brochure but apparently never produced), New instrument cluster (similar to but not identical to GT750A, most significant difference to GT are idiot lights in the tacho housing and the speedo doesn't read as high in the mph version (not sure about kph), New headlamp housing, new tail lamp (both of these similar but according to part numbers, not identical to GT750A), Turn signals (fronts are similar but not identical to GT750A numbers, rears are identical by part number), Head lamp stays (near identical to GT750A, once again, part number is slightly different).
Engine:
Reduced oil consumption accomplished by modifying the oil sealing mechanism and also by machining the critical parts of this mechanism to closer tolerances (allegedly reduces sump consumption to 1 litre per 1,600 klm).
Carburetor:
Main jet down to 87.5 from 90
Port valve timing to 35 degrees from 41
Accelerating pump timing down to 28 degrees from 30.
Accelerating pump capacity increased to 0.7 cc from 0.5 cc
Accelerating pump spring change (yellow in colour compared to stainless wire). Less subject to weakening.
(The setup changes were covered in the Suzuki Bulletins, #8 and #9)
Heat insulating gaskets at both Carby to inlet manifold and between manifold and engine. For the stud bolts securing the intake manifold, use bolts 5mm longer than those hitherto used. (This note about the studs is in the part interchangeability section but I assume that bikes that left the factory fitted with the insulators fitted already had 5mm longer stud bolts).
Marks on the choke mechanism allow unloader calibration without a gauge.
Spark Plug:
From NGK A9EFVP to NGK A9EFP (Gold to Palladium)
Contact Breaker:
Reversion to single points. Vacuum take off on inlet manifold plugged with rubber cap, B points removed, Speed relay removed, RPM sensor no longer in Tacho, Vacuum switch removed. (I would speculate that if you still had the vacuum switch etc under the tank, you have a bike that probably left the factory as an "M" and had the "new model" change over done at the dealership).
Ignition timing is given as 5 degrees (this is not given in the manual as a specific A model change but is mentioned. It's noted in the Bulletins as a general change along with the valve timing alterations etc).
Drive Chain:
New style O ring chain.
Chain oiler eliminated.
Electrical:
Minor changes in the wiring diagram.
The parts book shows that there is also a physical difference between the front and rear halves of the rear fender between the M and A that is not mentioned in the above booklet. They mount to the frame and each other in a slightly different way