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Post by jasong on Feb 8, 2014 21:25:43 GMT -5
All,
I've had my scooter for around 8-9 months now, and have loved it so far. However, I'm starting to notice some annoying issues. I'll keep them all in this thread as to not clog things up. Background info: Replaced hoses, spark plug, fuel filter. Drilled some small holes in bottom of air box (probably part of my problem). Roughly 900km's so far with proper oil changes.
1.) Lugging and rev limit: This is my biggest problem and annoyance. From a stop, at WOT, it will lug for 2 seconds, surge through 30 mph, and then start to slowly reach 50ish. My RPM's NEVER, EVER go above 5,200 RPMs. This has been a severe annoyance because I know I'm missing the peak power range around 7,000. Hills are a real challenge with this, and i'll really lug and max out at 45 even if I come strong into the hill. If I let off the throttle at all on a hill it will not regain speed.
Is this a roller weight issue? I think someone else found that this scooter has 14g rollers. I haven't taken mine apart yet. I'd like to upgrade to lighter sliders.
Also, I've always heard a rattling from the CVT when I accelerate from a stop for about 1.5 seconds, I think it's the belt slapping the case. Would a Kevlar belt help this?
2.) Does not like to start cold. Can be after only 4 hours and will have to crank for 30 seconds-1 minute off and on. Starter is cranking whole time, battery has enough charge. I haven't pulled anything off yet (i.e. fuel lines to check for flow, is this my next step?)
3.) Squeaky brakes: I've taken the front pads off and put anti squeak on the back and it hasn't helped. Anything I can do about it?
4.) My carb has a cap over the fuel/mix screw and thus I haven't adjusted it. I've read some about it, does this just need to be pulled out to access it?
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Post by JerryScript on Feb 8, 2014 21:37:04 GMT -5
1, 2, & 4 are probably related issues. Begin by setting your valves. Once that's done, pull that carb out and remove the cover on the air/fuel screw. The easiest way is with a special puller bit made for a drill, you can pick them up at most auto parts stores and hardware shops. Once that is removed, clean the carb, then re-install it and follow alleyoop's carb tuning instructions (you can find them in the tech section here).
The roller weight issue is one that has to be fixed by trial and error. Take out the current weights and put them on a scale to see what you have. You might want to go down a gram from what you have, and I do recommend switching to sliders.
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Post by jasong on Feb 8, 2014 21:45:19 GMT -5
Thanks for the response. I forgot to mention I have adjusted the valves and cleaned the carb less than 100 km ago. I believe I did the valves at .004 and .005 or whatever the common recommendation is. Without changing the rollers, do you think adjusting the fuel mix screw will help the RPM's and lugging? Isn't that in the realm of the main jet after 20 mph, not the mix screw? 1, 2, & 4 are probably related issues. Begin by setting your valves. Once that's done, pull that carb out and remove the cover on the air/fuel screw. The easiest way is with a special puller bit made for a drill, you can pick them up at most auto parts stores and hardware shops. Once that is removed, clean the carb, then re-install it and follow alleyoop's carb tuning instructions (you can find them in the tech section here). The roller weight issue is one that has to be fixed by trial and error. Take out the current weights and put them on a scale to see what you have. You might want to go down a gram from what you have, and I do recommend switching to sliders. |
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Post by alleyoop on Feb 8, 2014 23:19:22 GMT -5
The rattling are your weights they probably have flat spots and now they fit loose until they move up on the ramps.
As for the lugging you will have to adjust your fuel ratio mixture sounds like it is running lean needs a little more fuel . If this is a 50cc with 14 gram weights that is why your rpms are very low, you need to drop down to around 6 gram weights and that should raise your rpms by around 2000. If its a 150cc then 11-12 gram weights.
Alleyoop
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Post by jasong on Feb 8, 2014 23:44:59 GMT -5
The rattling are your weights they probably have flat spots and now they fit loose until they move up on the ramps. As for the lugging you will have to adjust your fuel ratio mixture sounds like it is running lean needs a little more fuel . If this is a 50cc with 14 gram weights that is why your rpms are very low, you need to drop down to around 6 gram weights and that should raise your rpms by around 2000. If its a 150cc then 11-12 gram weights. Alleyoop You guys are so helpful. This is exactly what I was looking for. That sounds spot on about the rollers flat spots. There's usually a corresponding lull in acceleration when I hear the rattle and then it kicks in. It's a 150cc, so I was thinking around 12. Should I order 11.5? If I'm getting nowhere near max RPM's, just go a little low in weight to be safe? I'm a 180lb rider with almost no extra weight in gear/tools. |
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Post by alleyoop on Feb 9, 2014 0:20:08 GMT -5
Ok it is a 150, yes you can go 11.5 on the weights.
To figure out what rpms your going to get figure on this:
ROLLERS= for every gram up or down it will change your rpms by 500-600
SLIDERS= for every gram up or down it will change your rpms by 200-350
So if you have 14 rollers and you drop down to say 11.5s that should raise your rpms around 1500 or so.
Alleyoop
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Post by jasong on Feb 9, 2014 11:08:00 GMT -5
So if I've got rollers but was going to switch to sliders, that gives me an extra 900 RPM's by my calculations. Which would bring me to 6000, assuming nothing else changes. Am I correct? Should I do more?
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Post by alleyoop on Feb 9, 2014 13:06:15 GMT -5
You said your rpms are currently only 5200 and the power band on the 150s is around 7500 rpms so you need to get the rpms to at LEAST 7K you will notice a big difference in performance and getting up to speed. If your scoot has a tach the redline is probably 8K.
Alleyoop
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Post by JerryScript on Feb 10, 2014 0:09:06 GMT -5
Don't forget to unplug that a/f screw. Then do a plug chop and see if you need to adjust the needle. Once you start getting your RPMs up, you definitely don't want to be running lean. There's a recent thread here on catastrophic failures that has a few examples of what running lean can do at high RPM.
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Post by jasong on Feb 10, 2014 0:55:43 GMT -5
Just read through ScootnFast's variator guide for the third time and am wondering if a contra spring change would help too? Heavier spring I'm assuming to get me up the hills? I'm going to try to take everything apart this week and weigh everything so I know where I'm at!
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Post by alleyoop on Feb 10, 2014 1:28:40 GMT -5
Do one thing at a time, putting in a stronger contra spring you will then need to maybe change to little heavier weights so it can open and pull the belt down for top end speed.
So either first put in the contra spring(which I really do not care for) reason is it puts a lot of pressure on the belts create more heat and wears them out faster, also it requires higher rpms before the scoot starts to move.
Alleyoop
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Post by jasong on Feb 20, 2014 19:31:18 GMT -5
Unplugged the A/F screw, adjusted it via the manual on here, and viola! I have acceleration! Still not where it should be (i.e.>5,000 when accelerating) as its around 4,000-4,500 during most of the acceleration. Total RPM's I've gotten on a flat is around 5,800, on a downhill I've gotten up to 6,200 RPM's. Uphills are more manageable now, but definitely could be improved.
Looking at sliders tonight and we'll see when I get them in.
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Post by alleyoop on Feb 20, 2014 19:55:32 GMT -5
From what you say your rpms are on the flats you need at least 2 gram lighter weights,
Alleyoop
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Post by JerryScript on Feb 21, 2014 2:19:06 GMT -5
And get ready to hold on to the handlebars when you go 2 grams lighter, you are gonna love it!
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Post by imnts2 on Feb 21, 2014 17:11:28 GMT -5
Anything is possible I expect but I suspect you need to check your valves and compression carefully. A slightly tight intake valve will mess up power and starting badly. It is always one thng at a time when I troubleshoot and fix a machine. And the first thing around a engine is get it starting and idleing right. and the first thing for that is compression. On a china scoot it is valve clearances. they often have soft heads that take a year or so to stop or slow down the valves receeding into the head.
Good luck
lefty2
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..BAD TO THE BONE..
