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DT 250B crankshaft bearings clearance
- Wessi
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DT 250B crankshaft bearings clearance was created by Wessi
Close to re-assemble the crankshaft I noticed the bearings I purchased aftermarket have C3 clearance. Today I saw in the parts list, C4 is original. Stupid question, maybe, but better don´t install? Does somebody have experience with C3 installed?
Don't want to open the cases next time again...
Comments are very welcome.
Don't want to open the cases next time again...
Comments are very welcome.
09 Dec 2019 05:00
#1
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- Pillsbury
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Replied by Pillsbury on topic DT 250B crankshaft bearings clearance
C4 has more internal radial clearance than a C3. Both have more internal clearance than a standard bearing. I would go with what Yamaha used. I have not used anything less than stock ratings, but I have used other make bearings.
1970 DT1-C Grand Prix race bike
1970 DT1-C Street tracker
1968 Honda CL90
1973 Honda CR250
1974 Honda MR-50
1966 Triumph Tiger Cub
1947 Mustang
1974 Suzuki TC185
1970 DT1-C Street tracker
1968 Honda CL90
1973 Honda CR250
1974 Honda MR-50
1966 Triumph Tiger Cub
1947 Mustang
1974 Suzuki TC185
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- RT325
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Replied by RT325 on topic DT 250B crankshaft bearings clearance
Left side is super tight on the shaft & in the case & not sure what mine are but can see why they recommend C4 on the left. C3 on the right would be good as only tight in the case & shaft slides in. If you got the left bearing off the shaft easily or the bearing wasn't tight in the case then C3 will be ok on that side too. [in my opinion]. Also yamaha have steel inserts in the case for the bearing in those early days so the bearing 'should' be tight in that no matter what. One more thing & unlikely on a big shaft like that but have seen numerous small motors where the bearing on the left has been spinning on the shaft so its a loose fit but move it out 5mm or more then its tight to get off [as it should be but] but of course should be tight all the way home to the crank wheel or ya getting nowhere.
09 Dec 2019 15:41
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- Wessi
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Replied by Wessi on topic DT 250B crankshaft bearings clearance
Tank you for your reply. Maybe I was wrong, the parts list writes for the DT 250 just Bearing 6206, the DT 400 has B6306 C4 ( 72mm outwr diameter instead 62mm and 19mm width instead 16mm) so different pair of shoes. A pitty, there is nothing written on my old bearings. So I will install my 6206 C3 Koyo bearings.
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11 Dec 2019 04:45
#4
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