quawk
2nd Gear
Posts: 150
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Post by quawk on Aug 22, 2022 11:19:31 GMT -5
Just wanted to post to thank Tim, Wayne, and all other members who have advised and helped me get my bike resurrected and up and running. After chasing my share of gremlins and glitches, I'm happy to report my bike is now running seemingly as it should and staying in a reasonable temp. range. For a mid sized bike it rides and handles well. Doesn't have the bog or dead spot that others report, but does have the slight vibration at around 3500-4000 that other members indicate is caused by a primary chain harmonic. I can live with that. Have even scored an original fairing and the rest of the touring kit. Again, thanks all. It probably wouldn't be running without this board.
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Post by timpa136 on Aug 22, 2022 12:21:24 GMT -5
You are most welcome. Good to hear it.
but does have the slight vibration at around 3500-4000 that other members indicate is caused by a primary chain harmonic. Some much more pronounced than others.
Worn trans. bearings and drive chain amplify the inherent harmonics.
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Post by HGH 770N on Aug 22, 2022 12:59:25 GMT -5
Glad you’re up and running. As Tim said the vibration comes through the gearbox and out through the drive chain. There is a video on here of a bike on a Dyno bench showing the drive chain “Whipping “ like crazy at certain RPM. Keep the Drive chain tight helps allot. Also I’ve rebuilt a few gearboxes with allot of end float on the main shaft. I wonder if this contributes to the issue??
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quawk
2nd Gear
Posts: 150
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Post by quawk on Aug 22, 2022 14:22:02 GMT -5
So am I misunderstanding the origin of the vibration? It's trans, bearings, and drive chain more so than the primary chain? Or a combination of those things plus the primary chain? My bike has 12,000 miles on it and the owner's manual shows notes from the original owner that the engine was dealer replaced at 2,000 miles. Would a basically 10,000 mile bike have trans. problems?? The original owner kept close track of the routine maintenance of this bike with notes kept in the owner's manual. Oil, coolant, tire changes etc.
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Post by timpa136 on Aug 22, 2022 15:20:43 GMT -5
So am I misunderstanding the origin of the vibration? It's trans, bearings, and drive chain more so than the primary chain? Or a combination of those things plus the primary chain? My bike has 12,000 miles on it and the owner's manual shows notes from the original owner that the engine was dealer replaced at 2,000 miles. Would a basically 10,000 mile bike have trans. problems?? The original owner kept close track of the routine maintenance of this bike with notes kept in the owner's manual. Oil, coolant, tire changes etc. Sounds like yours is just fine. When you have the opportunity to drive several others you may realize yours is smoother than others. My hi miler has the original trans bearings with no noticeable problems. Add a magnetic drain plug if you don't have it. Tim
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Post by wayne on Aug 22, 2022 18:49:59 GMT -5
So am I misunderstanding the origin of the vibration? It's trans, bearings, and drive chain more so than the primary chain? Or a combination of those things plus the primary chain? Congratulations and thanks for the update. Really good to hear! The origins of the harmonic are the engine itself. It's a characteristic of rotary designs, Suzuki spoke about it in the Japanese factory schools. I've even had a Mazda guy tell me they have it as well but it's masked by the twin and the car mounting. When the motor gets into the harmonic range, somewhere in that 3,500 to 4,000 rpm, it's transmitted into the primary chain and through the entire drive train. If you're primary is worn or the tensioner spring is old, it will be more likely to flail about from the engine induced harmonic. Similarly, the more bearings are worn, final chain poorly adjusted, the more likely the harmonic will be transmitted through the whole bike rather than being damped. In summary, nothing wrong with your bike. That harmonic was reported by Journalists in 1974 on brand new factory prepped bikes during the early publicity releases. Everything Roger and Tim have said. Ride some others in the future, you may be surprised how good yours may be. As Roger suggested re the movie: You may enjoy the whole 2 minutes but at least look from 1 minute and 10 seconds. The camera focuses on the final drive as the rpm transits the harmonic zone. I think it was 3800 rpm for that bike. It was also the most noticeable vibration of the 5 RE5s present and only 22,000 miles at the time. As a general rule, I've found the higher the mileage, the worse the vibration and that fits well with the hypotheses: re5rotary.proboards.com/thread/3020/dyno-day-video-movie
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quawk
2nd Gear
Posts: 150
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Post by quawk on Aug 29, 2022 13:17:26 GMT -5
Tim, the magnetic drain plug has to be a good logical idea. Will try to get one. Again, thanks to all who have helped me.
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Post by multistrada1 on Aug 29, 2022 17:34:26 GMT -5
AS mentioned, if you adjust the drive chain just a little bit on the tight side the vibration is reduced. Also, adjusting the rear ride height a little bit higher helps. Im using a ICON rear shock, which allows you to raise the back a bit without a harsh ride.
Great you are on the road, these bikes will high mileage well with some love.
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Post by Framitron on Aug 29, 2022 20:47:30 GMT -5
Quawk:
Multistrada's suggestion of the Koni/Ikon shocks are a huge improvement! They transform the ride so much. And slightly higher rear end seemed to make the steering a bit more sporty.
Timpas suggestion of a magnetic drainplug is a good one.
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Post by wayne on Aug 29, 2022 21:07:35 GMT -5
Quawk: Multistrada's suggestion of the Koni/Ikon shocks are a huge improvement! They transform the ride so much. And slightly higher rear end seemed to make the steering a bit more sporty. Timpas suggestion of a magnetic drainplug is a good one. I agree, I fitted mine with Ikon shocks and the improvement in comfort was significant although the bike was a little wiggly at speed (probably due to the slightly raised rear and a couple of other things). The base IKON was around 1/2" longer than the stock shock but I liked that aspect as well. Well worth the money over the stock units.
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quawk
2nd Gear
Posts: 150
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Post by quawk on Aug 31, 2022 19:16:28 GMT -5
Are IKON/Koni shocks one and the same? I doubt I will go to the trouble/expense of replacing the shocks but curious about the branding. I will probably never get to making this a high mileage bike, but good to know they can be.
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Post by Framitron on Aug 31, 2022 21:43:22 GMT -5
A number of years ago Koni sold off their motorcycle shock line to another company. (Koni still does automotive shocks) That company decided to flip the K-O-N-I letters around to form IKON. They offer the same exact shocks, springs and just about all of the replacement/rebuild parts and even the same part numbers.
They are still somewhat expensive and now there are other companies (Wilbers, Hagon, YSS, Ohlins, Race-Tech, Noleen) that you can check out.
What I did was wait until a used pair of shocks showed up on Ebay. The KONI/IKONs that work for the RE5 is the 7610-1394. I bought a used pair from a guy in Poland. They don't come up often. I saw a used and mint condition pair about 4 months ago up for sale but no one bought them. The late 70's GS-1000 has the same clevis and length. (I think... you might want to get a second opinion on that though..)
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Post by wayne on Sept 1, 2022 17:29:44 GMT -5
One of the very rare times when a product is in our favour down under. IKON is an Australian owned and based company.
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quawk
2nd Gear
Posts: 150
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Post by quawk on Sept 1, 2022 19:12:58 GMT -5
Framitron, Thanks for posting the part number for the IKON shocks that would work on the RE5. As I said before, I probably wouldn't pop for aftermarket shocks, but you never know when a great deal might come along and I may consider them.
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