blowit Posted June 2, 2009 Report Share Posted June 2, 2009 We were playing around with some crankshaft setups the other day and got curious as to what all you guys use. Billet or casted? Pinned, not just welded? If so, where is yours pinned at? (seen them pinned in several places and none of them make any sense) Bearings - For you guys running big motors, are you running the TZ PTO bearing, straight cut PTO gears, both, neither? Quote Link to comment Share on other sites More sharing options...
BellicoseBanshee Posted June 2, 2009 Report Share Posted June 2, 2009 Bearings - For you guys running big motors, are you running the TZ PTO bearing, straight cut PTO gears, both, neither? I am certain a 4mm cub is not exactly a "big" motor, but... I run a TZ on the PTO and standard bearings for the rest. Typical F.A.S.T. 4mm T&W crank. I needed a billet basket, and decided to go with the spring-tension basket with straight-cut gears (debated for a while, but decided to just fork the coin and get the gear/basket assembly). Maybe the straight-cuts are overkill, but what the hell... After looking at the design of the TZ, it appears to be a nonlocating bearing, so for a 4mm cub, it was probably not necessary. The basket/gear assembly is very nice and I will not have to worry about blowing out cushions... Common set-up, so it may not be very helpful to you. Quote Link to comment Share on other sites More sharing options...
VegasJeff Posted June 4, 2009 Report Share Posted June 4, 2009 I am certain a 4mm cub is not exactly a "big" motor, but... I run a TZ on the PTO and standard bearings for the rest. Typical F.A.S.T. 4mm T&W crank. I needed a billet basket, and decided to go with the spring-tension basket with straight-cut gears (debated for a while, but decided to just fork the coin and get the gear/basket assembly). Maybe the straight-cuts are overkill, but what the hell... After looking at the design of the TZ, it appears to be a nonlocating bearing, so for a 4mm cub, it was probably not necessary. The basket/gear assembly is very nice and I will not have to worry about blowing out cushions... Common set-up, so it may not be very helpful to you. It sounds like you just described my whole motor set up. :laugh: Quote Link to comment Share on other sites More sharing options...
dajogejr Posted June 4, 2009 Report Share Posted June 4, 2009 10mm, 115 rod crankworks forged crank. Inner and outer webs are welded. An NTN **Style** TZ Bearing on the PTO side, OEM bearing on the ignition side. TZ bearings are no longer made from Yamaha, so...what people do is use the NTN bearing equivalent and have the outer race machine with a groove to accent the case retaining clip (looks like a 1/2 moon) This is my personal belief...and opinion, but I don't think billet cranks are worth the money. However, now that they're coming down in price, coupled with the forged cranks that are getting phased out, I don't think we're gonna have a choice in the future... Quote Link to comment Share on other sites More sharing options...
blowit Posted June 4, 2009 Author Report Share Posted June 4, 2009 10mm, 115 rod crankworks forged crank. Inner and outer webs are welded. An NTN **Style** TZ Bearing on the PTO side, OEM bearing on the ignition side. TZ bearings are no longer made from Yamaha, so...what people do is use the NTN bearing equivalent and have the outer race machine with a groove to accent the case retaining clip (looks like a 1/2 moon) This is my personal belief...and opinion, but I don't think billet cranks are worth the money. However, now that they're coming down in price, coupled with the forged cranks that are getting phased out, I don't think we're gonna have a choice in the future... We have just had a few ideas over the past few months and were curious. By the numbers, the roller bearing on the PTO should hold WAY more radial load than a motor can make but they are not designed to handle axial loading very well. Straight cut gears can certainly cut down on axial forces but straights usually do not exhibit as good wear characteristics has helicals and they make more noise. Just pondering really. We are trying to build a map for new components this year but have to be cautious with the economic times. Our reduced work load here has allowed us to look at new parts innovations. We already have some fun stuff just getting finished up but will have room for more ideas it seems. B Quote Link to comment Share on other sites More sharing options...
dajogejr Posted June 4, 2009 Report Share Posted June 4, 2009 I have a TZ and factory helical gears Brandon, hundreds of passes on my 10 mil and no issues whatsoever. I ride sand, only sand or loose dirt type tracks as well. That's why when I see people tell me how much I need straight cut gears I just kinda laugh... Quote Link to comment Share on other sites More sharing options...
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