Just wondering if the main shaft and counter shaft bushings from a P series 100 motor can take the needle bearings for these places? 93 100 MX SUPER RAT Needle bearing # 931011 counter shaft # 931004. Bushing 100 B #901011 main shaft, counter shaft #901004.
Thanks
Both the needle bearings you are speaking were available for ace 90s as a racing option. They came with instructions on machining the cases to accept the larger diameters. (anyone still have that sheet?) On my 94A Wombat project when rebuilding It I discovered that the countershaft bushing had failed and the shaft had eaten into the case. I had the case bored and installed the 9301004 bearing to save the day.
You should read the discussion on the post " Pulling That Pesky Main Shaft Bearing". We had some fears of premature failure on the mainshaft bearing surface when using the needle bearing although I raced the modified 90 engine and the 93 early Super Rat for years with no problems. The 93A went back to a bushing probably for that reason.
Thanks for the reply. It was just a thought as I was looking at the 100 motor and a 100 road toad and noticed the needle bearing main shaft.I'm putting a modified cylinder (porting looks to be the same as in hop up for the 100) and thought that the needle bearings would be the way to go? I could use the specks for boring out the cases to take the needle bearings if anybody has them?
Have a great day
Paul at Strictly Hodaka probably has the bearings and a good machinist can measure them and fit them properly. I might stick with the bushing on the mainshaft because of the wear issues. As you may have read on the post I referred you to the 250 had a sleeve or "inner race" to protect the mainshaft and required a larger bearing.(on page 2).
Bearings are always better in reducing friction than bushings. If it's going to be an all-out racer I would go with the bearing however,if it's just a fun machine, long term reliability is probably more important. The horsepower gained is probably next to nothing but in racing all these small items add up. In the case of the countershaft bearing, probably because of it's size and much bigger bearing surface has proved to be reliable.
Thank you for the reply.
Just building one for everyday use so will keep the bushings as it seems that the needle bearings aren't very reliable, maybe because of size or manufacture?
