debbi
Scoot Junior
Posts: 16
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Post by debbi on Jun 21, 2018 17:52:39 GMT -5
2001 Derbi Predator O2. Noticed a whining when I rode the bike. Live in the middle of nowhere, was like 30 miles from home, so i decided to keep riding. The noise came from the back. Felt the rear wheel and theres a little bit of play. Nothing crazy, you cant see it move or anything but you can feel it shift and make a little clunk noise.
How bad is it to keep riding it like this? Anyone got any good videos/guides on how to fix it? I've got the service manual but it'd be great to actually see someone do this on a similar bike to understand what it's on about. If its too difficult or you need a massive amount of exotic tools, though, I was thinking of just riding her 'til she craps out completely, then sell her for parts or just chuck her.
Edit: Might mention it's my first ever scooter and I never really worked on any engines. Got it for about 400 bucks though so it's not a huuuge deal if it gets totalled, either by me riding it or me trying to fix it. Part of the reason I got it was to learn how to fix engines. How much skill in the workshop do you need for something like this?
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PirateLabs
Scoot Enthusiast
Posts: 296
Location: Bowling Green, KY
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Post by PirateLabs on Jun 21, 2018 18:47:47 GMT -5
2001 Derbi Predator O2. Noticed a whining when I rode the bike. Live in the middle of nowhere, was like 30 miles from home, so i decided to keep riding. The noise came from the back. Felt the rear wheel and theres a little bit of play. Nothing crazy, you cant see it move or anything but you can feel it shift and make a little clunk noise. How bad is it to keep riding it like this? Anyone got any good videos/guides on how to fix it? I've got the service manual but it'd be great to actually see someone do this on a similar bike to understand what it's on about. If its too difficult or you need a massive amount of exotic tools, though, I was thinking of just riding her 'til she craps out completely, then sell her for parts or just chuck her. Edit: Might mention it's my first ever scooter and I never really worked on any engines. Got it for about 400 bucks though so it's not a huuuge deal if it gets totalled, either by me riding it or me trying to fix it. Part of the reason I got it was to learn how to fix engines. How much skill in the workshop do you need for something like this? Do you hear the noise when you spin the rear wheel by hand with the scoot up on the center stand with the engine off? If you do, it could be a clutch roller bearing, or an axle or gear bearing, or the wheel bearing. You will have to determine exactly where the noise is coming from. A stethoscope is really handy here. (Harbor Freight sells them as do some auto stores) Or, you can take a large screwdriver and press the round end of the handle to your ear, and place the tip in various areas and this will help you isolate the source of this noise. Others that know your specific scoot can be more help to you. I would also check your axle nut to make sure it has not come a bit loose. Bill
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debbi
Scoot Junior
Posts: 16
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Post by debbi on Jun 22, 2018 2:58:50 GMT -5
Do you hear the noise when you spin the rear wheel by hand with the scoot up on the center stand with the engine off? If you do, it could be a clutch roller bearing, or an axle or gear bearing, or the wheel bearing. You will have to determine exactly where the noise is coming from. A stethoscope is really handy here. (Harbor Freight sells them as do some auto stores) Or, you can take a large screwdriver and press the round end of the handle to your ear, and place the tip in various areas and this will help you isolate the source of this noise. Others that know your specific scoot can be more help to you. I would also check your axle nut to make sure it has not come a bit loose. Bill Thanks. Axel nut seems fine. How freely should the wheel spin when the motor is off? Mine is nowhere near as free as the front wheel, but i always assumed that this was the way it was supposed to be with the transmission in idle.
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Post by pinkscoot on Jun 22, 2018 6:32:46 GMT -5
I have a Derbi Predator o2 Replica. Check out what Pirate Labs suggested as well as the transmission fluid. It may need changing if its never been done.. When you spin the wheel there should be a very small amount of play, thats nothing to worry about, a large amount could be a problem. if you stand at the back and the wheel moves left to right then you have a problem. A video might help us diagnose better.
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debbi
Scoot Junior
Posts: 16
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Post by debbi on Jun 22, 2018 8:54:25 GMT -5
I have a Derbi Predator o2 Replica. Check out what Pirate Labs suggested as well as the transmission fluid. It may need changing if its never been done.. When you spin the wheel there should be a very small amount of play, thats nothing to worry about, a large amount could be a problem. if you stand at the back and the wheel moves left to right then you have a problem. A video might help us diagnose better. Amazing, thanks! You saying that there should be a small amount of play put my mind at ease already. Thought it was suposed to feel like the front wheel. Yeah, video coming up for sure, soon as I figure out how to make it. Im gonna do some research myself, but if you got any good guides/videos on transmission fluid change on hand I'd love to see them.
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PirateLabs
Scoot Enthusiast
Posts: 296
Location: Bowling Green, KY
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Post by PirateLabs on Jun 22, 2018 9:21:18 GMT -5
There will be some resistance when you spin the rear wheel on the center stand because you are turning all of the gears in the transmission and also the clutch bell. When doing this test you should be listening for any noises made by a bad bearing...like grinding noises, inconsistent sounds while turning, etc. Unless it is very hard to spin, like your rear brake is dragging or something, I would not be concerned with the resistance, I would concentrate on listening.
Bill
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Post by ThomasTPFL on Jun 22, 2018 9:26:25 GMT -5
Don't kill it or trash it whatever you do!!! It's a Derbi! We don't have enough of them over here.
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debbi
Scoot Junior
Posts: 16
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Post by debbi on Jun 22, 2018 9:41:06 GMT -5
There will be some resistance when you spin the rear wheel on the center stand because you are turning all of the gears in the transmission and also the clutch bell. When doing this test you should be listening for any noises made by a bad bearing...like grinding noises, inconsistent sounds while turning, etc. Unless it is very hard to spin, like your rear brake is dragging or something, I would not be concerned with the resistance, I would concentrate on listening. Bill Ok, thanks, good to know. I fiddled with the brake line screw thing and tired loosening it. made no real difference. On the resistance/sound, there's a video coming soon, if you wanna see for yourself.
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debbi
Scoot Junior
Posts: 16
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Post by debbi on Jun 22, 2018 9:44:04 GMT -5
Don't kill it or trash it whatever you do!!! It's a Derbi! We don't have enough of them over here. Yeah, I fear I've become emotionally attached to her already. Already named her Debbi. If I can't make her work, and can't sell her, I guess I'll just have to gift her to some gearhead and hope they can bring her back to life.
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debbi
Scoot Junior
Posts: 16
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Post by debbi on Jun 22, 2018 9:55:47 GMT -5
I have a Derbi Predator o2 Replica. Check out what Pirate Labs suggested as well as the transmission fluid. It may need changing if its never been done.. When you spin the wheel there should be a very small amount of play, thats nothing to worry about, a large amount could be a problem. if you stand at the back and the wheel moves left to right then you have a problem. A video might help us diagnose better. Ok so here's the video. Let me know if seeing anything else would be helpful. www.youtube.com/watch?v=OGfTJdboImoAs a side note, After I finished filming there was a bit of a scary problem where the throttle would get stuck on open. Not a fun feeling. Shut her off and when i started up again she was back to normal idle, but it was sticky when i opened her. I imagine something to do with the throttle line? Researching that as well but any ideas there would be very much appreciated!
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debbi
Scoot Junior
Posts: 16
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Post by debbi on Jun 22, 2018 10:48:40 GMT -5
I have a Derbi Predator o2 Replica. Check out what Pirate Labs suggested as well as the transmission fluid. It may need changing if its never been done.. When you spin the wheel there should be a very small amount of play, thats nothing to worry about, a large amount could be a problem. if you stand at the back and the wheel moves left to right then you have a problem. A video might help us diagnose better. Just while you're here: what kind of transmission fluid would you recommend? What's important to look out for? Edit: As far as I can figure out from the sevice manual, she needs SAE 75w90. If she's hard to start when cold, would it be better to get oil with a lower w value? Is that a bad idea?
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Post by ThomasTPFL on Jun 22, 2018 11:44:49 GMT -5
Transmission oil weight will have no effect on starting as it's completely separated from the engine.
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Post by pinkscoot on Jun 22, 2018 11:59:51 GMT -5
The sticking throttle could be a lean condition. With it that hard to start it sounds like you need a carb cleaning and tune. You made me go take pictures. To do the transmission change you unscrew the black cap shown here:
Thats also where you fill it. Then you remove the silver bolt underneath. Yours might not be that clean. Catch the oil and dispose of it properly. Look at it for any signs of chipped gears or metal. Then you refill with 110cm of the proper transmission fluid like the case says. Easy Peasy.
Here is a link to Brents tutorial on carb cleaning. Yours may look a little different but its the same idea. According to the shop manual the idle screw should be out 2 turns as a starting point. These are well made and tuned scooters. Until you have more scooter knowledge I would leave the cylinder, carb and exhaust stock. There are several of us here that did the BBK and expansion exhaust and Dellorto carb that are banging our heads tuning them. get it running right and starting right up and enjoy it for a while. I have a thread here on mine you are welcome to read 49ccscoot.proboards.com/thread/16736/derbi-predator-lc. If I had it to do over I would have left it stock. I have a parts bike that will be a naked build and I'll do it differently. Edit: Thomas has one as well and he is very knowledgable with these.
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debbi
Scoot Junior
Posts: 16
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Post by debbi on Jun 22, 2018 12:21:58 GMT -5
The sticking throttle could be a lean condition. With it that hard to start it sounds like you need a carb cleaning and tune. You made me go take pictures. To do the transmission change you unscrew the black cap shown here:
Thats also where you fill it. Then you remove the silver bolt underneath. Yours might not be that clean. Catch the oil and dispose of it properly. Look at it for any signs of chipped gears or metal. Then you refill with 110cm of the proper transmission fluid like the case says. Easy Peasy.
Here is a link to Brents tutorial on carb cleaning. Yours may look a little different but its the same idea. According to the shop manual the idle screw should be out 2 turns as a starting point. These are well made and tuned scooters. Until you have more scooter knowledge I would leave the cylinder, carb and exhaust stock. There are several of us here that did the BBK and expansion exhaust and Dellorto carb that are banging our heads tuning them. get it running right and starting right up and enjoy it for a while. I have a thread here on mine you are welcome to read 49ccscoot.proboards.com/thread/16736/derbi-predator-lc. If I had it to do over I would have left it stock. I have a parts bike that will be a naked build and I'll do it differently. Edit: Thomas has one as well and he is very knowledgable with these. Thank you so much, amazing! I can't believe you went out and took pictures! Above and beyond! Yeah, certainly leaving everything as it is for a good long while. I imagine you're tired of my line of dumb of questions, but if i could ask one more: the only scooter transmission oil i can find near me is API gl5 80w90. In the service manual it says to use Agip Gear Synth 75W-90 (also gl5). Do you reckon the 80w90 will be alright?
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debbi
Scoot Junior
Posts: 16
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Post by debbi on Jun 22, 2018 12:36:18 GMT -5
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