3rd Gen Jeremy

So here's the situation. Blew an apex seal last year. Finally got around to rebuilding her and decided to port and polish her at the same time. Get the motor back together and it's got 2 problems. I need some advice on them.

1) The end-play is .005" and according to the Rotary Aviation video, is out of spec. He says that the bearings are bad and need to be replaced. My question is whether or not that advice is correct and which bearings since there are 4 of them?

2) When I turn the motor by hand, I get a nice smooth turn for 2 rotations then I get hung up on the 3rd and it takes about 20 ft-lbs to push through it. What could be causing this? Is it possible that I aligned something incorrectly?

Any advice would be greatly appreciated.

Thanks,
Jeremy

2Lucky2tha7

iTrader: (3)

They are referring to the torrington bearings. They are located in front of the front stationary gear with a "plate" in between them. This is usually the case when end play is out of spec. If they were however replaced, then you will need to replace the spacer with a thinner one to decrease the endplay.

2Lucky2tha7

iTrader: (3)

Also, read this through:
http://www.mazdatrix.com/faq/pulley.htm

3rd Gen Jeremy

Ok, I've torn the motor back down and inspected everything and it was fine.

I put it back together and everything is great as far as smooth rotation. Here's what I think happened:

1) When I put the rear stationary gear in, I torqued all the bolts before torquing my tension bolts. I think this may have cocked the stationary gear by just a slight amount when the tension bolts were torqued. This next time, I torqued the tension bolts before tightening the stationary gear bolts and seems to be fine.

2) The endplay was still out of spec by a little over .001 so what I ended up doing based on the advice from dan at pineapple racing was to grind down the spacer by that much. I did this by using a die grinder with a scotch brite pad on it. The spacer gets really hot so be prepared to dunk it in some water periodically or just wait for it to cool down. I put the spacer back on the motor and checked the endplay, it comes in right at .002 which is on the tight side of the range but still within spec.

I hope my trials and tribulations help a future engine builder or at least provide some interesting reading.

Thanks for the help,
Jeremy

JunpoweR

iTrader: (1)

Humm never had a problem with end play when rebuilding a motor and yes you always tighten the tension bolts first! But if this ever happens to me then I know what went wrong! THANKS!