Weird noise/roughness at low power??

[Rashid510]

Really Rashid?!

Really. Its life did have some people from Alta do silly things on it.

 

[Matt]

I have beat the daylight out of mine I wouldn't be shocked if it is the bearings. I have already gone through all the other bearings some more than once lol. Just crossed 100 hours a few weeks ago. I also need to rebuild the front brake master cylinder and find the gaskets for the top of stearing stem. When on the stand the rear wheel does not spin freely at all and I think it is because of the cogging. I replaced the gear oil about a month ago and there was a bunch of sludge in it similar to what others have experienced. I did take the cover off and tried wiggling the gears then and didn't notice any play but I wasn't really aware of how little play constitutes bad bearings so I will try again and see. It has gotten very loud compared to normal.

 

[2018SM-R]

I have had to replace the right side motor bearing on two Altas who's owners complained of exactly that sound. However, this was above and beyond the "normal, for an Alta" type sound. If the bike's new to you the only way to check is to pull the right side motor cover and using your hand, try and wiggle the pinion gear up and down. If you feel even a bit of slop it's time for a bearing. The Alta manual will tell you how to remove/re-install the cover.

Do you know the part number for the right side bearing? Chatting with liquid and they have a few.

 

[Rashid510]

Do you know the part number for the right side bearing? Chatting with liquid and they have a few.

4700091-02 BEARING, BALL, OUTPUT, 6006-C3

 

[Mark911]

I've seen two different parts used to date. One was a sealed ball type and the other an open roller. If you have a roller type the bearing should come as two separate parts, the outer race with the rollers and the inner race which goes over the motor output shaft. If its the ball type it'll be one part. The removal and re-installation process requires some skill. it's not for the novice. The bearings are typically press fit to the motor shaft. In the case with the roller type bearing, it'll need to be carefully cut and chiseled/cracked apart and extreme care must be taken to prevent ingress of debri and/or accidental cutting of stator windings.

 

[Rashid510]

I've seen two different parts used to date. One was a sealed ball type and the other an open roller. If you have a roller type the bearing should come as two separate parts, the outer race with the rollers and the inner race which goes over the motor output shaft. If its the ball type it'll be one part. The removal and re-installation process requires some skill. it's not for the novice. The bearings are typically press fit to the motor shaft. In the case with the roller type bearing, it'll need to be carefully cut and chiseled/cracked apart and extreme care must be taken to prevent ingress of debri and/or accidental cutting of stator windings.

And this is why its a bad idea.

 

[Matt]

What is the downside of operating the bike with the cogging. Does anyone think this will damage anything or just sound annoying? I have been riding mine with it cogging pretty loudly at lower speeds. If I need to replace the bearing I am not going to until the winter. Not sure if I really want to try and cut it myself also. I have enjoyed working on the bike in most cases but I don't want to ruin the motor.

 

[Rashid510]

What is the downside of operating the bike with the cogging. Does anyone think this will damage anything or just sound annoying? I have been riding mine with it cogging pretty loudly at lower speeds. If I need to replace the bearing I am not going to until the winter. Not sure if I really want to try and cut it myself also. I have enjoyed working on the bike in most cases but I don't want to ruin the motor.

The cogging noise will not effect performance (aka will just be annoying). If you really need to replace the bearing then I would wait. @Matt if you can sending a video will help to provide more insight

 

[Matt]

The cogging noise will not effect performance (aka will just be annoying). If you really need to replace the bearing then I would wait. @Matt if you can sending a video will help to provide more insight

Will do. I am going to change out the chain and sprockets ( not related to the noise just need to change them) as well as change the gear oil again and then see how loud it is and send a video if it is still doing it. Also I got some liquid gasket maker to replace the gasket on the gear reduction cover but wasn't sure if this is the best option.

 

[Rashid510]

Will do. I am going to change out the chain and sprockets ( not related to the noise just need to change them) as well as change the gear oil again and then see how loud it is and send a video if it is still doing it. Also I got some liquid gasket maker to replace the gasket on the gear reduction cover but wasn't sure if this is the best option.

I got gaskets for the timing and the reduction cover. What weight oil are you using?