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Post by averageguy on Jun 21, 2013 18:49:48 GMT -5
I've convinced myself that my motor "tick" is the valve clearance not being set right. It sounds like it is coming from the valve area anyway and the ticking does increase as the motor gets hot which seems to be a symptom of this problem from what I am reading. I ordered up a set of feeler gauges and will have a go at it when they arrive. I have been watching some youtube videos for some other similar bikes and I think I can figure it out. Doesn't look too bad... we'll see I guess. I'm trying to stay confident Shifting is a little clunky but manageable once you get the hang of it. A full manual transmission I think is a much better option and I miss having a clutch but the semi-auto is passable. Once up to speed and through all the shifting I am still impressed by the ride of this bike. I just adjust my riding to avoid shifting... so I roll a few stop signs  It really is a decent bike for the money and cruises nice. Very light and nimble. So far I have not experienced any problems with bolts coming loose or anything like that. The bike is holding together much better than I expected it would. I still check everything often just in case... My first time to the gas station it cost me a whopping $1.27 to top her off with premium. Now that I super mega like! If I can get this ticking issue cleared up and get the replacement sprocket on to stretch out the shift points and top speed a bit I will be one happy camper... ;D |
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Post by prodigit on Jun 22, 2013 1:09:53 GMT -5
I think, as long as the ticking isn't too obnoxiously loud, it can't really harm. The settings may be tight, but those things will wear out, giving you natural clearance. There is a possibility that perhaps a metal flake got stuck inbetween the valves. I would suggest before doing the adjustment, to put some Chemtool B12 in the tank (only like between $3 and $6 in a local auto store).
B12 is more aggressive than seafoam; but since your tank is so small, I basically go through a tank on one afternoon (averaging 100 miles max per tank).
could be that the B12 removes some carbon deposit as well and makes the valve sound go away.
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Post by prodigit on Jun 23, 2013 19:28:30 GMT -5
Oil maintenance interval is pretty high on this bike, almost like a 50cc's change interval, partly because it does not use gear oil, but uses motoroil for the gears.
I've seen a lot of debris in the oil. I would recommend to do the oil changes at km:
0
50 (50km after first interval)
150 (100km after second interval)
300 (150km after third interval)
600 (300km after 4th interval)
1000 (400 km after 5th interval)
1500 (500km after 6th interval)
2000 (500km after 7th interval)
3000 (every 1000 consecutive km's).
I currently done the 600km interval. I'll see how the oil is after 1000km, to see if I need to update those numbers.
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Post by averageguy on Jun 24, 2013 1:53:05 GMT -5
I went for my first longer distance ride and almost didn't make it home. I was cruising along when suddenly the motor cut out. I pulled off to the side of the road. I was about 30 minutes from my house kind of in the country. When I was inspecting the engine I noticed oil all over the kickstand. Apparently oil was coming from the motor?? The bike after cooling down a bit did restart and I just slowly rode until I came upon a small engine repair shop. The owner came out and was laughing at me basically saying "what kind of engine is THAT?" Really giving me the business. What could I say... there I sat with my Chinese bike broken down in his parking lot. I just ate crow and bought oil and drove off. Luckily I made it home ok. But I am fairly certain now this bike is leaking oil from one of the gaskets. I am about ready to chuck this into the scrap metal bin at work and call it a lesson learned. It's a shame because it rides nice. I just don't trust it now.
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Post by prodigit on Jun 24, 2013 2:04:11 GMT -5
Where did the oil come out of?
Did you make sure you did not overfill it?
It takes only very little oil in the crankcase (about 1 qt max).
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Post by averageguy on Jun 24, 2013 3:09:48 GMT -5
[replyingto=prodigit]prodigit[/replyingto]>Where did the oil come out of?
I'm not 100% sure to be honest I think where the two pieces of the housing goes together on the bottom I saw some oil... all I know is when I pulled over the first thing I noticed was black oil on the tip kickstand with like a spray pattern so I checked the oil and it was off the dipstick. I am not sure that is what caused it to die out but may have just been coincidence. I had been running it almost wide open for a bit. I was on a stretch of 2 lane highway.
>Did you make sure you did not overfill it?
Yeah I had it filled correctly... if it was overfilled it was not by much at all. It was where it should be on the dipstick. Much less than 1 quart... maybe like 2/3 quart?? Definitely not a whole quart in there.
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Post by prodigit on Jun 24, 2013 16:57:44 GMT -5
The oil goes black really quick. Make sure you change it often!
For the first 600miles I have already done 4 oilchanges.
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Post by scooter12 on Jun 24, 2013 19:47:02 GMT -5
No, Roketa motorcycles will last one, if they are taken care of properly. Meaning no stunts, no over the speed limit racing, ect.. Just ride to enjoy it. Hear the manuals are worthless on the motorcycles as they were on the scooters. A joke.. Like the manual may say, use this type of oil, but the oil dipstick it says a different type only. Same with tires, manual says one size but tires say another( better go by the tire size..lol). But if you every owned a Chinese motorcycle, you know all this stuff. Check bolts and screws before taking out on the road, to make sure everything is tight. Hate to have a major component fall off while riding- like the foot gear shifter.  |
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Post by prodigit on Jun 24, 2013 21:39:00 GMT -5
It's actually not going to fall off, even with the clip removed, it's just loose.
But the funny thing is, that I purchased a 100 pack of zip ties for $6 or something, and one zip tie stays longer on there, than the original clip.
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Post by CopperDeer on Jun 25, 2013 1:30:06 GMT -5
Lost track of this thread / progression for a while, just caught back up, was very interested in this bike from the day you announced you'd be ordering it, prodigit. Seems to be coming along nicely. About what I expected as far as the level of quirks to work out but for the price and especially the performance you describe, incredible. Don't get me wrong, not enough to reconsider my beast of a European pedigree 49cc 2T, especially with the planned BBK... but I might just have to pick one of these up after I give away my ATM50 if I can still get that same price. I'm trying to use the ATM50 some still to keep the miles off the Derbi and save on gas, not having much fun doing it though haha
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Post by prodigit on Jun 25, 2013 3:00:11 GMT -5
@ averageguy: I have ridden 2 trips of 1 hour each, almost 2/3rd of the tour @ WOT, and have not experienced any oil leaks so far.
My only complaint is that the gas tank is empty so quickly. After 1,5 hours riding WOT, it has used 75% of it's tank (~0.8 gal), and needs to be fueled up again. I wished I could make use of the remaining gasoline, and at least get a 150Mile range
@ Copperdeer: I initially bought this bike to replace my ATM50.
And although Roketa accelerates much faster than the ATM, it's top speed stock was not significantly faster than my ATM50 (perhaps 5-10MPH faster).
With the sprocket change (I put a 34T in, but I would recommend a 36T for optimal power distribution), I get a gas mileage equal better than the ATM50, with added faster acceleration, and faster top speed (60-65MPH).
I've been contemplating changing the sprocket to a 31T for ultimate gas mileage.
Here's my reasoning:
A 34T should be considered an overdrive, as the top speed is close to the top speed of a 41T, and below the optimal sprocket of 36T.
On average, with a 33T, in 3rd gear, the bike acts like with a 41T in 4th gear.
If I switch down to a 31T sprocket, in 3rd gear, I will have similar performance of a 36T in 4th gear.
However 4th gear with a 31T, will be seriously overdriven. I'd probably be able to go ~45-50MPH tops with it in 4th gear, however in 3rd gear, the bike should have sufficient RPM's to go top speed of 65MPH.
Doing it this way, I could cruise around town 35-40MPH @ a reasonable 2k-3k RPM.
I'd probably ride in 1st, and 2nd in the city, and 3rd gear on the highway most of the time, and use 4th gear only when going in the suburbs on 35 to 45MPH roads, to save on gas.
It would be a cruising gear, much taller than an overdrive. Doing so, I should be able to attain the magic 120-125MPG; but also would have almost zero acceleration.
That gear would be good to keep me going at those speeds, as the 34T shows me it still has quite some acceleration between 30MPH and 40MPH.
Something peculiar about this engine is, that it has good low end torque. But unlike most chinese scoots, the higher the RPM's, the torque does not increase significantly, only very little.
I think it's optimum pull is between 2k and 4k RPM. Anything above 4k RPM has some extra power, but not that much more (like doubling the RPM's does not double the torque, only marginally increases it).
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Post by averageguy on Jun 25, 2013 15:13:04 GMT -5
[replyingto=prodigit]prodigit[/replyingto]Well I have 126 on the odometer and I have already changed oil 3 times... probably overkill but trying to keep it clean from metal. I just changed it again today and it was looking much cleaner. I did not see any metal flakes this time as in previous oil changes. There was no oil on the ground under the bike where I parked it so maybe I am just paranoid about there being an oil leak. The jury is still out on that one. I tested out the kick starter today to see how it worked and it started right up first try with very little force needed to kick it. Works nice. Reassuring to know its there in case of a starter or battery problem. I also changed out the spark plug with a NGK. I received the new sprocket in the mail yesterday (thanks for that prodigit) and might try to get it on next week. I will ride to work today on the bike if the rain stays away coz it's time to start saving gas and make this thing pay for itself  |
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Post by prodigit on Jun 25, 2013 20:32:30 GMT -5
You're welcome  Hope things work out on the sprocket, and bike. With a smaller rear sprocket, the engine does not go in such high revs, and might be running cooler; less oil splashing going on. I think it's possible that some of the oil got splashed out the crankcase, via the overfill drain. |
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Post by prodigit on Jun 26, 2013 21:19:35 GMT -5
What are your opinions?
I think I'm going to try the 31T sprocket upgrade.
Instead of riding in 4th all the time, I'll be riding in 3rd; using 4th for 35-50MPH roads as a cruising gear; since those roads (35-50MPH) are the majority of my roads.
I do this mainly to lower RPM further and increase gas mileage, as well as for the experience.
I will have to learn how to downshift.
By rotating the left foot outward (to the left) and using the heel to hit the shift down, is the easiest way to downshift.
With the stock 40T sprocket I got 85MPG.
With the 34T sprocket, I get 100+MPG
So roughly guessed, with the 36T should be getting 95MPG, and the 31T I should be getting
110MPG.
With the 34T, first gear is still a bit short. Second gear is long, and barely can keep up with traffic, but it can. Third gear needs to rev high to keep up with traffic, and by 4th gear acceleration is mediocre but it is there. By further lowering the rear sprocket teeth, final gear acceleration will be traded in for lower RPM and lower MPG, lower wear and engine heat.
Changing to 31T, should make 1st gear heavier and taller, meaning longer acceleration in a faster gear (1st gear) before shifting to second gear. Second gear will barely be able to keep up with traffic, so I expect I'll have to rev it high before going into 3rd gear, which would give a similar gear ratio than a 36T in 4th gear. Still acceleration in that gear is acceptable for the speeds, sometimes the ride is asking for an extra gear there, which will be created as with a 36/40t rear sprocket in 4th gear the revs will be just as high per speed as with this 31T sprocket in 3rd gear.
So instead of focusing on final gear = top speed, which is standard for a well tuned bike; now I'll focus on 3rd gear = top speed, and final gear = cruising gear.
There's really not much calculation to be done, as ~30T is the smallest sprocket that would fit, but the front sprocket is 15T, so chain wear will be high. The next logical step would be a 31T, as a 29T will more than likely cause clearance issues with the chain and the fork.
I do this change to get a good econo ride. But if the ride is not working out, I will just simply switch it back to 34T.
I will keep you updated with my findings!
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Post by scootnwinn on Jun 26, 2013 22:19:51 GMT -5
Constantly lugging an engine with extremely low gearing is very hard on it especially if it isn't broken in. I know you won't care digit but for the rest of you thinking he might be on to something, he's not. Adding a windshield will have similar effect on mpg without the damage to the engine and transmission. I hope everyone is seeing this adventure for what it is and not for what he so desperately wants it to be. This is a bike that is running so lean the choke must be on constantly. Does it get good mpg? Sure it isn't getting enough fuel... Anyway take these reviews with a grain of salt...
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