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OSSA 350 GRIPPER MAIN BEARINGS.


chappo
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Guys, what main bearings are you using in your OSSA Grippers.

The ones i took out are SKF ( OTHER BRANDS ARE AVAILABLE ), 6205 2 RSH .

I only ask as i read this in an OSSA manual, bearing in mind its not a manual for the 350 Gripper.................

NOTE: The left main bearing (OSSA Part No. 991-141) is slightly different than the right main bearing (OSSA Part No. 991-140). They are essentially the same bearings, but the internal clearance between the balls and races of the left bearing are greater than in the right. This difference is noted by the letters "C3" either stamped or printed on some part of the left bearing (Fig. 76 and 77). It is not recommended that a bearing without this "C3" marking be installed as a left main bearing.

I know these bearings would have had a rubber seal in them which was removed hence RS rating.

Also noted is the absence of seal carriers they are just tapped into the crankcase, seems odd !!!

Thanks. 

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It should be 6205 standard on the right (ignition side) and 6205 C3 on the left, without seals (sealed bearings are called RS in SKF code). Radial shaft seals on the outer sides of the engine are 25x42x8 in FKM material, i used Freudenberg BABSL seals in 25x42x6 size which fit perfectly.

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  size/ref quantity
crankshaft left bearing 6205 C3 1
crankshaft right bearing 6205 *(NJ205) 1
gearbox bearings 6205 1
  6303 1
  HK1412 1
  BK1616 1
gearbox axle needle bearings 14x18x9,8 2
  14x18x12,8 1
crankshaft main seals 25x42x8 FKM 2
gearbox/front sprocket seal 28x40x7 1
clutch pushrod seal 6x16x10 1
gear lever oring 2,5x14 2
clutch needle bearing HK2020 1
kickstarter oring   1
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Thanks RMS, the above is excellent info for the rest. Just for clarity, these are the same spec for a 350 Gripper ?:icon_salut:

I notice you give two seal thicknesses 6mm and 8mm , are they different each side?

Edited by chappo
added question
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These are the specs i noticed on my 350 gripper while rebuilding my bike. The original seal was 8mm thick, but i only found 6mm seals, but it makes no difference (as for the clutch pushrod seal thickness)

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8 hours ago, rms said:
  size/ref quantity
crankshaft left bearing 6205 C3 1
crankshaft right bearing 6205 *(NJ205) 1
gearbox bearings 6205 1
  6303 1
  HK1412 1
  BK1616 1
gearbox axle needle bearings 14x18x9,8 2
  14x18x12,8 1
crankshaft main seals 25x42x8 FKM 2
gearbox/front sprocket seal 28x40x7 1
clutch pushrod seal 6x16x10 1
gear lever oring 2,5x14 2
clutch needle bearing HK2020 1
kickstarter oring   1

Can I ask RMS, where is the above info from, do you have a Gripper manual?

Edited by chappo
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I took notes when I rebuilt my bike. By the way, talking about bearings: front wheel bearings are 6201 2RS (need 2), rear wheel bearings 6203 2RS (need 2), steering bearings 30204 (need 2, same as TR80 250), steering bearing seals Nilos 30204AV (SKF). As I know, there is no Gripper manual, you should use the Ossa 5 speeds manual, at least for the bottom engine 'cause top engine is different.

Edited by rms
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Here is usefull information/specs for TR80 350, translated from a post i've written for a french forum.
 

  size/ref quantity
crankshaft left bearing 6205 C3 1
crankshaft right bearing 6205 *(NJ205) 1
gearbox bearings 6205 1
  6303 1
  HK1412 1
  BK1616 1
gearbox mainshaft needle bearings 14x18x9,8 2
  14x18x12,8 1
crankshaft main seals 25x42x8 FKM 2
gearbox/front sprocket seal 28x40x7 1
clutch pushrod seal 6x16x10 1
gear lever oring 2,5x14 2
clutch needle bearing HK2020 1
kickstarter oring 2,5x18 1

*(May be replaced by a roller bearing, shoulder placed on inner/crank side)
Front wheel bearings : 6201 2RS x2
Rear wheel bearings : 6203 2RS x2
Steering tapered roller bearings (same on 350 & 250): 30204 x2 and the seals (SKF) nilos 30204AV

ENGINE
Exhaust o’ring 4x44mm in FKM material
There is no specific engine gasket kit for the TR80. The Artein gasket kit J0000SS000246 (Ossa 350) may be used for the central crankcase and sides, but won’t fit the exhaust or cylinder head.
Crankcase gaskets are 0,9mm thick.
Cylinder base gasket is 0,5mm thick.
Cylinder head gasket is 0,6mm thick, made of copper.
Ignition is 1,3mm to 1,8mm BTDC = 14,5° to 17° BTDC
Woodruff key is 3x5x13mm. Yamaha 90280-05001 may be used.
Rod kit may be found at Nuova Mazzucchelli, (BCO 0438). Can be found at Italkit, ref BC.9438
Primary chain is a duplex euro series 06B2, 9,525mm, 50 pins

Crankshaft seals from Yamaha part 93102-25446 should fit.

Side clearance for engine shafts (from Ossa 5 speeds manual):
crankshaft : 0,1 to 0,2mm (rod big bearing should be centered)
gearbox mainshaft : 0,5 to 0 ,9mm
gearbox layshaft : 0,25 to 0,4mm
gear drum : 0,2 to 0,3mm
kickstarter : 1,5 to 2mm

FRONT SPROCKET
following refs may be used with a spacer behind (520 chain):
Afam 30300
JT Sprocket JTF 569
from 10 to 15 teeth, used on Kawasaki KDX 200/250 and Yam YZ250 1983

CARB (original Amal)
Fuel petcock is right hand thread, M12x1,5mm, same as Bultaco/Montesa
Amal L-2627/408 (MK2 concentrics serie 2600).
Choke lever on the left, 27mm venturi.
« Spanish » Amal, british Amal have a groove for the rubber manifold, MK1 float needle valve on the spanish MK2… every parts can still be ordered at the Amal company.

part Amal ref notes
main jet 376/100-130 130
pilot jet 124/026-15 15 fitted on the carb body beneath the air tube
choke jet 124/026-40 40 fitted in the bowl under the small tube
needle jet 622/079-105 105 two stroke type without side hole
needle 2622/063 2B1 fitted on 3rd clip
throttle slide 2622/0601 cutaway N°1
air jet 2622/13535 3,5 under the intake adaptator
bowl 2622/192 2 stroke type, no threads in the bowl
cold start plunger 2622/079 sold as a kit with its spring, plunger, seal...


Air screw should be unscrew from 1 turn to 1,5 turn according to Amal. 2 stroke bowl is different from the 4 stroke.

FRONT BRAKE (110x25)
Ferodo FSB826
Newfren GF.1155
EBC 935G

CLUTCH (according to the TR80 yellow notice)
Oil is SAE90 for gearbox/axle or engine SAE30 (equal to modern 15w50 or 20w50, depending on the oil brand). For your information, Ipone BOX2 is 10w40 and ATF Dexron III is thinner than engine 10w30)

Plate kit is made of 5 friction plates + 5 steel plates. The thicker steel plate (2mm) goes first (on the engine side), stack ends with a friction plate.

Surflex 1202
5 friction plates
4 steel plates 1,5mm
1 steel plate 2mm

Surflex 1202/B
5 friction plates

Barnet 302-63-50001 kit : 5 friction plates
Agpa, TJT and CMS seem to make kits for Ossa

HEADLIGHT
Gonelli 40.103.00

SHOCKS
360mm length
8mm bushing on top
15mm bushing on bottom
About Betor, you should choose « hard » springs, 40 lbs can’t be used, and 50 lbs is for really light drivers.

BETOR FORK
radial shaft seals 35x47x10. This size is common on italian motorcycles mounted with 35mm Marzzochi fork (Aprilia, Moto Guzzi, etc)
There is a spacer under the seal, 36x47x4 in aluminium
19,5 cc oil in each fork leg

fork springs are 28mm OD 3,6mm wire 57 coils 480mm free length

Swingarm bushes are non-standard size 21x25x45mm probably made of nylon, shoulder is 3mm thick
feel free to correct me for any mistake.

Edited by rms
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