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Post by phatboy on Feb 19, 2020 17:49:31 GMT -5
Hi,
I want to get my 2005 Eton Beamer going again, I quit riding it because it's just too slow. Can't recall all details but it's stock 49cc, derestricted, with mods. Acceleration is acceptable for what it is, but I'd like a better top end, can't get over ~45 mph on flats. Would be nice to go 55.
A couple years ago I was going to just break down and get the JOG 90 long case from scrappy, so glad I didn't as they went out of business about when I was going to order and I might not have gotten it. I see a lot of short cases on eBay from ATVs but no long cases. Does anyone know a reliable source for new Jog 90 long case engines? Or even a used one I can rebuild?
If that doesn't pan out... Option 2 I will do a 70cc bbk on my engine.
But, I got to fix the gears before I even start that. The final gear ratio is way too tall at 13.54:1 and that is likely the reason for the low top end. I would settle for 11:1 final gear ratio. From what I read you want to keep the primaries on this due to bearings but replace secondary, primary is 52/13 or 4:1, so something around 31/11 for secondary would be doable.
I can't figure out if the normal short case gears for jog 50/minarelli, etc, will fit here, does anyone know.
Thanks for your help
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Post by Zino on Feb 19, 2020 18:08:39 GMT -5
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Post by phatboy on Feb 19, 2020 19:35:32 GMT -5
From what I have been reading, most 2t 50cc scoots use around 11:1 gearing, so by upgrading I would just be making it like any other 2t scoot, and 70cc would make that better. My Eton has 13.54:1 gears and it is too low even for 50cc, I max out the revs and going downhill doesn't help edit: did research on Eton matrix, it has 36/13 and 48/12 gears, or 11.07:1, that is about what I am after
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Post by Zino on Feb 19, 2020 20:22:51 GMT -5
Get the power first so you can push the gears. You also need the power to over come the wind resistance . When you go above 55mph you need twice as much horsepower than 45 to overcome the wall of wind .
I have built a couple eton beamer and have broke 50 by gps with just pipe bbk and a variator . The upsized variator did add 2-3 mph by itself
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Post by Zino on Feb 20, 2020 9:21:33 GMT -5
Here is a calculator to show how much horsepower to overcome the wall of wind. I used to have a motorcycle horsepower to speed chart based on this formula www.wallaceracing.com/Calculate%20HP%20For%20Speed.phpCoefficient of Drag Use 1 most scooters are way less aerodynamic . Frontal Area Use 5-7 square feet . you can tuck down and get closer to 5 weight of car/scooter add your weight and the scooter weight. Put in your desired speed Example use 1 drag 6 square feet 400 lbs 40 mph 3.18 hp stock build 50 mph 5.81 hp sport build 60 mph 9.68 hp mid race build 70 mph 15.02 hp race build I have put in gears in many scoots a 30 % upgrade in gears does not increase speed by 30% without extra horsepower . I doubled horsepower and my top speed only took advantage of 50% of the theoretical gear maximum
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Post by repherence2 on Feb 20, 2020 10:06:12 GMT -5
Jog 90 + exhaust + upgears = run 60 all day reliably.
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Post by dexameth on Feb 20, 2020 12:04:33 GMT -5
My 56 is pushing it to the max... like full tuck and no wind at all I got it to 56. Nice to know the gearing as I never really looked into it. Explains how me and my friend keep up off the line but I'll just slowly walk away hehe.
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Post by phatboy on Feb 20, 2020 13:20:38 GMT -5
Here is a calculator to show how much horsepower to overcome the wall of wind. I used to have a motorcycle horsepower to speed chart based on this formula www.wallaceracing.com/Calculate%20HP%20For%20Speed.phpCoefficient of Drag Use 1 most scooters are way less aerodynamic . Frontal Area Use 5-7 square feet . you can tuck down and get closer to 5 weight of car/scooter add your weight and the scooter weight. Put in your desired speed Example use 1 drag 6 square feet 400 lbs 40 mph 3.18 hp stock build 50 mph 5.81 hp sport build 60 mph 9.68 hp mid race build 70 mph 15.02 hp race build I have put in gears in many scoots a 30 % upgrade in gears does not increase speed by 30% without extra horsepower . I doubled horsepower and my top speed only took advantage of 50% of the theoretical gear maximum Thanks, that a good reference The 45 is actually a speedo reading it probably is really going 40. I used a gps for a time, I recall I maxed out at 37 true mph before variator/clutch mods, with speedo around 42. I haven't tested with GPS since that as my mount broke Stock these 49cc 2t engines are rated at like 5.2hp. With my mods I might be getting close to that 5.81 figure. The engine does have decent acceleration, my 2t 49cc stock actually accelerates better than my friend's 4-stroke 139qmb with bbk and A9 cam, just my top end sucks (despite being slower my friend's top end is like 5 mph higher than mine) So shouldn't I be going a lot faster than 40? I do have an oversize variator and performance clutch, tried different rollers and springs and belts and those are what got me from actual 37 to (estimated) 40. I can do a bbk I just fear that without gears first I will be disappointed at the top end, and since these Etons seem to have weird parts in their transmissions I want to get that nailed down first. Anyone know what gears will fit in this, what I should look for, etc.
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Post by phatboy on Feb 20, 2020 13:23:08 GMT -5
Jog 90 + exhaust + upgears = run 60 all day reliably. Trust me I would love a Jog 90 long case engine, just have had zero luck finding a complete one, I would even take a basket case and rebuild it but can't even find that
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Post by Zino on Feb 20, 2020 19:15:46 GMT -5
Are you maxing out your variator have you done the sharpie test .
My stock eton was gps 40 mph average speed both ways after variator low 40's pipe an bbk cruise at 45 peak at 50 mph plus mph . BBK & pipe gives more speed through higher rpms my stock beamer pipe was basically done at 8500 rpms after kit and pipe 9400 rpms is where it quit .
On My Zuma gears added between 6-8 miles per hour and I went with a 33 % up gear going from 14.4 to 11 to 1 Theoretically i should have picked up 15-16 mph .
If you go gears first you might pick up up 4-6 mph .
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Post by 90GTVert on Feb 20, 2020 23:57:40 GMT -5
I put a BBK on an Eton with the stock 13.5 gears. It would do ~50 with me on it with a stock exhaust and a HOCA variator paired with the Polini Sport 70. To me, the easy route is to put a 70cc kit on it. A sport kit should serve you well. Then see how you like that with it in tune. From there, you have the option of changing the pipe or the gearing or both. An aftermarket pipe will really wake up a 2T if it's the right exhaust for the job. 11:1 gears work fine stock. My Tritons were 10:1 stock. Stage 6 sells a secondary gear set that I pair with E-Ton Beamer primaries in my 1E40QMB gearboxes to get 11:1. Link below. www.scootertuning.ca/en/gears-secondary/71005-stage6-14-52-secondary-gearing-cpi-vento-keeway.html
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mattyslimz
Scoot Enthusiast
Posts: 222
Location: Northern Virginia
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Post by mattyslimz on Feb 21, 2020 10:08:01 GMT -5
I always had the idea the ratio was 13.55 in my RX8 but paired with the JOG90 pulley I see a max of 53 mph, so I doubt it’s 13.55. It does have great off the line though. Without the bbk and pipe it’s hard to get into the 50s let alone stay there, the ratio is there stock (on most shortcase 1e40qmbs) but the stock bore/porting and pipe make it hard to even get up into the 50s and hold it.
If you do swap the whole case and or do some gear changes. I recommend watching Mr.Brents channel on YouTube. In a build series he installs new gears with reinforcements, implementing an extra Eton Beamer bearing into an 1e40qmb case. This looks to make everything back there more solid and reliable.
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Post by phatboy on Feb 21, 2020 12:53:30 GMT -5
I put a BBK on an Eton with the stock 13.5 gears. It would do ~50 with me on it with a stock exhaust and a HOCA variator paired with the Polini Sport 70. To me, the easy route is to put a 70cc kit on it. A sport kit should serve you well. Then see how you like that with it in tune. From there, you have the option of changing the pipe or the gearing or both. An aftermarket pipe will really wake up a 2T if it's the right exhaust for the job. 11:1 gears work fine stock. My Tritons were 10:1 stock. Stage 6 sells a secondary gear set that I pair with E-Ton Beamer primaries in my 1E40QMB gearboxes to get 11:1. Link below. www.scootertuning.ca/en/gears-secondary/71005-stage6-14-52-secondary-gearing-cpi-vento-keeway.htmlI had a bit of sticker shock at that gear set but I guess you got to pay to play. That set would give me 11.2:1 if I got the tooth counts right. I did some searching and found a used 10:1 gear set from a Triton for a lot less, but I would have to swap the whole set (as the secondaries just about same ratio as Eton). But I keep reading about an extra bearing on the Eton primary, so how does that work, can this bearing swap on to Vento primaries or do I basically need to keep the Eton primaries?
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Post by 90GTVert on Feb 21, 2020 13:36:31 GMT -5
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Post by phatboy on Feb 21, 2020 14:08:09 GMT -5
Thanks for your help. Yeah, that Triton gear set I found does not have the nub on the end for the third bearing, so I'm going to go with the stage 6 kit, I will do that and the 47mm bbk together, I don't want to do one without the other. Does anyone know if any notching will be required for a 47mm bbk? I think this engine has a 10mm wrist pin if that helps
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