|
|
Post by prodigit on Jun 27, 2013 3:06:31 GMT -5
I know you always want to look at the negative side of things. I probably listen better if you're not always looking down on other people without reason. Because I don't agree with you on one topic, you should not assume I don't on another. The choke is merely adjusting AF ratio's; you can tune the carburetor to a sweetspot, where it's working most optimally. The carburetor is still letting  -99% of the air fuel mixture in the cylinder, which is pretty close to what it would be when it was jetted correctly. it's not running lean, when the choke is set correctly; it's just not letting the full 100% of mixture flow go to the engine, or would be the same if the bike was jetted correctly, and the throttle was just opened to -99%, instead of fully opened. I don't know about lugging the engine. The transmission and clutch probably will give out sooner than the engine. The engine still has power spare with a 34T, so I'm gonna go for it anyway. Not to go WOT, but to cruise around. I don't know if it causes a lot more wear than when one would go just as fast at 7k RPMs. I think at higher RPM's there's more wear. Since the engine is broken into (I'm at just over 870km right now, did about a 3 hour wot ride today on the interstate), I might switch to mixing heavier oils (diesel oils, like 15W40) with the recommended oil 10W40. I feel like above 500 miles (~800km) on this engine, it starts to run smooth. For the break-in anything above 10W40 is overkill. I'm still trying to determine the perfect oil mixture, but the transmission needs heavier oil than the 10W40 for the engine. Reason being that a lot of the metallic debris is from the gears, and the clutch sometimes is slipping. The gears need 80W90. The engine needs 10W30 to 10W40. I think the best compromise would be to mix 10W40 with 15W40, as I tried 15W40 last time was too heavy; perhaps now it'll run better on 15W40. |
|
Freshman Rider
Currently Offline
Posts: 57
Likes: 0
Joined: Jun 5, 2013 21:13:28 GMT -5
|
Post by averageguy on Jun 27, 2013 16:49:17 GMT -5
[replyingto=prodigit]prodigit[/replyingto]>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.
Just put your toes under the front lever and pull it up... I don't even use the rear lever at all... no problem works great. I pull my leg up rather than pivoting at the ankle. The rear one seems useless to me. It might work alright if the angle between the two levers was different. As it comes stock the rear lever is too low and can't really push it with the heel enough to make a shift. Its probably a generic part and doesn't work too well on this bike's tranny 'coz there is too much throw in it. I though maybe attaching some sort of block onto it might work to raise it up a bit to give it more throw when pressing it with the heel. Most other semi-autos don't even have that rear lever contraption on them.
|
|
Freshman Rider
Currently Offline
Posts: 57
Likes: 0
Joined: Jun 5, 2013 21:13:28 GMT -5
|
Post by averageguy on Jun 27, 2013 17:06:55 GMT -5
I have three trips back and forth to work on mine... up to 180KM... racking up the fuel savings and keeping mileage off my car  ...It might be my imagination but it does seem to be loosening up a bit. I am finding it easier to shift as the mileage increases. Probably the clutch getting worn in a bit. This might also have something to do with the fact that I am more used to where she likes to be shifted. It's always important to find the right spot  ... I can still hear the tick but it has not gotten any worse. It might actually be a little less. I seem to not notice it as much maybe I have just become desensitized to it. I had some guy at a stop light today yelling out his car window asking me what kind of bike it was... I just told him $800 Chinese Bike (Hard to get into too much of a conversation with a full helmet on). His comment to me was "nice bike" ;D ... Made me feel all warm and fuzzy inside Hahahaha. I took the lower side plastics off my bike and I think it looks just fine without them. They just get in the way monitoring stuff under there and block the oil dipstick anyway. Poor design. I figure it probably helps a bit with airflow around the engine for cooling purposes. No sense holding that heat in there. Some of my co-workers have started calling me "Easy Rider" at work now... with a heavy dose of sarcasm of course... they think they are sooo funny  |
|
Freshman Rider
Currently Offline
Posts: 57
Likes: 0
Joined: Jun 5, 2013 21:13:28 GMT -5
|
Post by averageguy on Jun 27, 2013 17:23:01 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. How you know he's lugging the engine you can hear it? As somebody who actually has this bike I can attest that what prodigit is recommending makes sense. A sprocket change on these bikes is very desirable and there is lots of room to play with before gut pulling the engine will become an issue. I have found prodigits feedback very informative, accurate, and valuable in my decision as to what sprocket to upgrade my bike to. Keep up the good work prodigit and never mind the haters  |
|
|
|
Post by prodigit on Jun 27, 2013 20:24:03 GMT -5
Thanks! I'm just short of 1000km's on mine, and some parts are getting loose too. Somewhere in the back something is ticking, I think, everytime I hit a bump, I think it's the rear wheel rod levelers or whatever it's called, those things to keep the rear wheel rod at a fixed position, to adjust the chain tension; but I'll have to look in detail. With regulating the choke while riding, it's easy to find the optimal fuel/air mixture, because the bike performs better when you hit that sweet spot. In the sweet spot, I have gotten speeds of upto just over 70MPH on the speedo, that is leaning forward hard. Regular speeds are 60-65MPH tops on the speedo with the 34T. I'm only 170LBS, so gotta keep that in mind. I've noticed that there is no particular fuel that works better than the other. When the bike is jetted too lean, BP Premium gives that tad extra power, but with regulating the AF ratio with the choke, that same 'perfect air/fuel mixture' and performance can be gotten with regular too. The only difference is MPG. With regular, my MPG drops by 5, from 100MPG with BP premium to MPG with regular fuel. Now I'm only gonna fill her up with regular, as the cost of BP Premium ($3.999/gal) does not work out better, financially, compared to regular ($3.499-3.599/gal). So even if MPG's drop, overall you'll still be paying more with BP Premium gasoline per mile, than with regular. averageguy, whenever you feel upto it, and the bike has warmed up, take it out on a wot trip of at least 10 minutes with the 36T sprocket. I'd be interested in what your top speed amounts to. As far as lugging the bike, you can always refrain from going WOT in final gear. If you're easy on the bike, it won't lug; especially not because the clutch prevents that the RPM's get too low. A 31T is going to be very small! I think a 34T is small, at stop lights I can barely keep up with other cars, and if I go wot acceleration, I can accelerate just like peppy cars would. With a 31T it'll be a true econo rider! Slow acceleration, probably recommended to accelerate to nearly top revs in 1st gear, to keep up with the rest of the cars. |
|
Sophomore Rider
Currently Offline
Posts: 201
Likes: 1
Joined: Feb 27, 2013 2:23:40 GMT -5
|
Post by CopperDeer on Jun 27, 2013 21:58:31 GMT -5
31T sounds a bit dramatic then, if you had more gears I'd say go for it, but with a 4-spd I'd prolly stick with the 34T. I would agree that there's a fine line between tweaking the performance/efficiency and compromising the design and bogging it too much with crazy gearing. I don't know that it would cause damage though, I agree with prodigit that high RPM low load/throttle is worse than low RPM high load/throttle within reason.
A really legit mechanic once told me you get the greatest overall efficiency going hard at low-mid RPM's (within reason) for a few reasons, other than obviously less revs = less combustion, having the throttle open reduces pumping and frictional losses over partial throttle. I shift my cars like a mad man to keep the RPM's under 2k, no problems in a quarter million lifetime miles yet. On a forum for an older Honda Civic Hybrid 5-spd I used to own just about everybody found their best MPG with a "1-2-5" shift pattern, go nearly WOT from a stop through 1st and 2nd to your cruising speed then quickly ease off into 5th.
You really should upjet your carb if it is really that lean, though. I could understand a little choke getting it to haul balls but idk hard to tell, yours sounds kinda severe.
One question I did have for you, prodigit, is how does the parts market for this engine / bike look? For me that's more important than reliability, everything will break eventually, having my Derbi has shown me how much a pain having a rare machine can be for sourcing parts.
|
|
|
|
Post by prodigit on Jun 28, 2013 0:53:52 GMT -5
Parts can be gotten from Roketa. Only stock parts. No aftermarket available.
The CDI is not custom, the engine is not your custom chinese engine, not to mention the transmission. What worries me is the clutch, that already starts skipping a bit.
Concerning gears, like I said before, going down to 31T basically is the same as having a 36T sprocket with a 'fifth gear'. In first gear acceleration, initially, it will accelerate slower. However once the clutch grips, it should accelerate just as fast as the 36T, because of less shifting. The gears become very long though (like you need to accelerate long in 1st gear).
And normal riding in 3rd, not 4th gear, unless you're going over 35MPH, then 4th gear will be that extra gear you've felt like you needed, but didn't have.
I'm going for it anyway. If my engine breaks, you all know what for.
It doesn't pay off to put yet another sprocket in, but if you buy the bike stock, and plug in a 31T from there (~$40-47), you can get that money back within 80 fuelups, lol, as each fuelup saves you ~$ 50ct, compared to the stock sprocket!
I may indeed be going very low with it. I decided I wanted to try it out, and see what happens. As soon as Rebelgears reply my email, to see if they can fabricate the 31T, I will let you guys know.
|
|
Sophomore Rider
Currently Offline
Posts: 201
Likes: 1
Joined: Feb 27, 2013 2:23:40 GMT -5
|
Post by CopperDeer on Jun 28, 2013 11:07:36 GMT -5
Interesting, good points. I guess once you get past 10-15 MPH it's just a matter of spacing the gears out a little more. I think you said you liked starting out in 2nd with the stock sprocket anyways? Sounds like at least with the 34T you realized some performance gain in addition to fuel savings. And like you mentioned, top speed wouldn't necessarily be affected since 3rd would be a similar ratio with the 31T as 4th is stock. I'm certainly not one to complain about having an "ultra-overdrive" gear  I'll be keeping up with the developments for sure. |
|
Freshman Rider
Currently Offline
Posts: 57
Likes: 0
Joined: Jun 5, 2013 21:13:28 GMT -5
|
Post by averageguy on Jun 29, 2013 0:58:58 GMT -5
I made it to work tonight for 4th time without incident. I had her up to 60MPH on the spedo (probably really 55 MPH in actuality) and she was still pulling but I didn't want to push too hard... the RPMs were up pretty high. I wouldn't want to run 60MPH for super long distances but for the stretch of open road I encounter on my way to work I think it's not a problem... No oil loss so far after a fair bit of riding... In hindsight I think what I saw on the kickstand might have been the chainlube I put on spraying off... I'm not seeing any stains under the bike at all after sitting. Clean as a whistle. I might try another road trip to the flea market about 45 minutes from my house Sunday just for kicks... maybe after the new sprocket install if I feel ambitious. Its a fairly long stretch of flat two lane highway through the country... should be a good test and a good confidence builder. I didn't get stranded last time but I also chickened out and turned back home before getting to the flea market. BTW I absolutely LOVE the new mirrors I bought... they are awesome! I highly recommend them as they provide a GREAT view and look good on the bike. Unless you have the physique of Olive Oil (I am more of a Bluto) I think replacing the rear view mirrors on this bike is a must do for safety. Attachments:
|
|
|
|
Post by prodigit on Jun 29, 2013 1:49:56 GMT -5
Yeah, they are. I was actually hoping to find some convex mirrors, but current mirrors work ok for me; not good, but I can use them; to look behind the left or right lane. I can't look straight behind myself because they are too close to the center like you say, even for skinny guys... Looks like you're riding without the front wheel fender |
|
Freshman Rider
Currently Offline
Posts: 57
Likes: 0
Joined: Jun 5, 2013 21:13:28 GMT -5
|
Post by averageguy on Jun 29, 2013 7:42:08 GMT -5
[replyingto=prodigit]prodigit[/replyingto]Yeah I thought the front fender looked kind of cheesy so I punted on it... I don't see any real need for it. I figured I would just hit it on something and crack it in no time anyway taking it in and out of the garage.
I left the plastic pieces off that around the steering column also. They were being a pain in the butt to get on so punted those as well. To me it looks less scooter-ish and more dirt bike without them...
Artistic license! What the heck hahha.
|
|
|
|
Post by prodigit on Jun 29, 2013 8:50:30 GMT -5
LOL I do fear more water entering under the handlebars. If you want an even more dirtbike looks, you can remove the plastics on the handlebars too (never done it, but on most scooters it's just clicked together. That way you'll have a steel black handlebars, way more dirt-bike-ish than the plastics they put on there (I actually prefer metal handlebars over the plastic cover). Installing the rear sprocket should take less than 15-20 minutes time. Should it be, when you adjust the chain, and there's still too much chain slab at the farthest setting, then check your chain, somewhere on the outside, one of the links has a clip. You can take off that clip and shorten the chain there. I didn't knew, and bought a chain breaker and re-installed the original rod. Taking out the rod with the chain breaker is no problem. Putting it in there is. I bought this one: www.amazon.com/gp/product/B000GTXNI6I also bought some cheaper ones, but they where for bicycle chains, not motorcycle chains. |
|
Freshman Rider
Currently Offline
Posts: 57
Likes: 0
Joined: Jun 5, 2013 21:13:28 GMT -5
|
Post by averageguy on Jun 29, 2013 10:33:48 GMT -5
Yeah I might have to take a look under those handle bar plastics to see whats under there... you got me thinking now hahha... nothing better than riding naked (not me the bike) Thanks for the sprocket tips! I am eager to see what kind of difference it will make. |
|
Freshman Rider
Currently Offline
Posts: 57
Likes: 0
Joined: Jun 5, 2013 21:13:28 GMT -5
|
Post by averageguy on Jul 1, 2013 0:30:29 GMT -5
[replyingto=averageguy]averageguy[/replyingto]This is the reason the Chinese bikes are geared so low... a common sight throughout Asia... They are built for their target market not the US market... Attachments:
|
|
|
|
Post by prodigit on Jul 3, 2013 19:16:25 GMT -5
Did a 300 km, ~200 mile WOT trip to Okeechobee from Miami.
On the way to the lake I had wind in the back, and the meter was constantly at 70MPH (~65MPH GPS).
On the way back, I had a lot of wind against, and the 34T sprocket makes the bike really susceptible to speed drops due to wind. On my way back I had speeds ranging from 55MPH to 60MPH.
About 50% of the trip I was tailgating a truck, to get there faster.
The bike, with it's thin tires, was susceptible to side winds a lot. The front wheel would sometimes move 1 inch sideways due to wind blasts.
Something I didn't have with my Honda.
And while riding at WOT, having strong winds against me, I noticed that the clutch slipped regularly. That's probably the reason for the lousy gas mileage.
I did the whole trip 100MPG to, 95MPG back (due to winds).
If it wasn't for the truck I was tailgating, I would probably have been closer to 90MPG.
The clutch worries me a little. I don't know if it slips because of lower revs (if it grips better at higher revs, a centrifugal clutch), or because of the wrong oil or what the reason is...
I'll be forced to mix Diesel oil (15W50) with my 10W40, as the clutch probably is a wet clutch.
Doing so, will lower MPG. In order to compensate that, I'll have to do another sprocket change.
So I'll probably go downto a 31T, and switch to 15W40 in the future.
Yet another trade of performance for gas mileage, and longetivity.
I'm almost at my 1500 km oilchange. The 1000km oilchange looked good.
Thus so far, the oilchanges of a 50cc hold true on this bike:
50km
150km
300km
600km
1000km
1500km
2000km
3000km
4000km...
....
It will be interesting to see how the oil looks after the first 1000km oilchange (at 2k to 3k miles).
Once the engine has been broken into, usually after 500 km, it runs so much smoother.
At this moment, ~1000km it runs perfect, so I think I'm going to do the switch to heavier oil, for the sake of the gears and clutch.
|
|
-99% of the air fuel mixture in the cylinder, which is pretty close to what it would be when it was jetted correctly.
