Posts
82
Joined
7/10/2018
Location
Pittsburg, IL
US
Alright so I'll start off by saying I change the oil and filter on this bike every 3hrs. Same with cleaning the air filter. About a month ago I took it around my track and didn't even get 300yrds down the track and the rear tire locked up. I gassed it and it bogged and died. I went to kick it and it stuck. The 2nd attempt it turned over. And 3rd kick it fired back up surprisingly. It had very subtle motor noise.
I ride it up to where we sit and my buddy says he hears nothing and takes it around the track. Half way around it starts knocking hard. Hard enough at 150yrds we could all hear it. He rode it back up and gave it a steady throttle and it stayed the same loud knock.
Long story short I took it too a mechanic that's we've known for years and does great work. He ran every test he could without pulling it apart and couldnt find anything. Only 3% leak down on the valves after 45hrs! He told me to take and ride it and see what happened. So the first time I ride it it sounds like normal no noise. The second time out it starts in again with the subtle knock and I can feel it through the pegs.
Were both at a loss but I dont wanna split it just yet incase anyone else has had issues with these rmz's and can point me in a direction. I'm thinking rod bearing but idk. It's only got 45hrs and I ride it considerably hard as in on the limiter alot on the track but I wouldnt think itd go at 45hrs either. If anyone knows or has had one act up or maybe some info on what it sounds like any help would be appreciated before I scatter the bottom end on the bench.
I ride it up to where we sit and my buddy says he hears nothing and takes it around the track. Half way around it starts knocking hard. Hard enough at 150yrds we could all hear it. He rode it back up and gave it a steady throttle and it stayed the same loud knock.
Long story short I took it too a mechanic that's we've known for years and does great work. He ran every test he could without pulling it apart and couldnt find anything. Only 3% leak down on the valves after 45hrs! He told me to take and ride it and see what happened. So the first time I ride it it sounds like normal no noise. The second time out it starts in again with the subtle knock and I can feel it through the pegs.
Were both at a loss but I dont wanna split it just yet incase anyone else has had issues with these rmz's and can point me in a direction. I'm thinking rod bearing but idk. It's only got 45hrs and I ride it considerably hard as in on the limiter alot on the track but I wouldnt think itd go at 45hrs either. If anyone knows or has had one act up or maybe some info on what it sounds like any help would be appreciated before I scatter the bottom end on the bench.
Youre at 45 hours and ride the bike hard. Open the top end and take a look. Or gamble it and lose some engine cases.
Without a video its hard to say. You can localize the noise with a mechanics stethoscope. Harbor freight sells them for $3.
The Shop
Sounds like crank to me as well, just unlucky as these things are normally bulletproof. They are a noisy engine but safer to split the case's and find nothing than go the other direction. Might just end up costing you some gaskets and seals fingers crossed.
If you took the old rod and really used a lot of pressure it was possible to feel it rocking on the pin, hence the noise.
The new crank/rod had zero movement as far as rocking. Grab that rod and see if you can get it to rock side to side, not up and down.
Pit Row
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