50cc phantom restriction... By corneilius (Read 979 times)

[corneilius]

I have a 50cc Roketa that was unrestricted when I bought it. From that time until about 2 weeks ago it has been going about 40mph on straight away. From 2 weeks ago it has been getting only 20-25mph. It is almost like a switch was flipped and it will no longer rev higher like it used to which results in significant power loss. Like the subject suggests, it is almost like it is restricted again without any physical manifestation that I can see causing it.

When it happened, it made the switch all of the sudden, then went back to normal for a day, but then right back to phantom power sucker entity....thing....never to return.

Can someone direct me to a common sense solution or do I find a good priest?

[Bashan]

Jul 6, 2011 17:43:26 GMT -6 corneilius said:

It is almost like a switch was flipped.

[/size][/quote]
Well that sure sounds electrical. Generally fuel problems will manifest slowly as you ride more. Also, they won't correct themselves for a day and then return. Electricals however are elusive and can come and go, and then come and not go . However, before you go ordering things pull the bucket and inspect the engine compartment. Make sure nothing's hinky with the throttle cable or a hose came loose, airbox included. Then I'd order a coil and a CDI and swap them out one at a time, I bet it's one of them. Order the performance stuff if you want, but spending more money on a part doesn't fix the problem. Rich

[corneilius]

I recently had the cdi replaced due to spark problems. I also bought a new coil at the time just in case, yet never installed it. I will do that and see what happens.

Thank you!

[Bong]

It maybe as simple as a loose ground wire, Now wich one will drive you crazy Is the cdi or rectifier/regulator running very hot? also check the fuses it might be an easy fix.

[sunlproblems]

first off check all plug wires my cdi was not clicked in and it ran sometimes check and replace all fuel and vacum lines check the intake i had a 125 that did that and it was cracked just enough where sometimes it ran great other time veryslow do the spray bottle test on them spray all around if the bike runs better when its wet then you found the problem

[corneilius]

Well I replaced the Coil and nothing. If anything I'd say now the bike takes longer to turn over comparatively. Could I have replaced the old CDI with a New-Bad one? I sprayed the hoses with no discernible change. Fuses are good and wiring from what I can tell is where it needs to be.

Forgive me, but this is not a problem that comes and goes. I am forever stuck at 20mph. It seems to me that there is some "self destruct" device cleverly put in by the Chinese to make the scooter go slower and now need repair...

Any other ideas O Great Ones?

[sunlproblems]

test the power into the parts with an ohm meter go from the batt. down good luck it takes time todo but thats what a real shop would do also you may have a wire grounding to the frame take off all the plastic and start checking wires

[Cruiser]

Welcome to Scooter Doc, corneilius. How many miles do you have on your scoot? Does it have a tachometer? Problems in the CVT can give the same results that you are having, but they can also be verified by the tachometer readings.

[corneilius]

It just rolled over to 700 miles and no it does not have a tachometer. How else could I find out if it is the continuous variable transmission?

[corneilius]

no hope huh?

[Cruiser]

It looks like you already have weeded out the ignition system. A tachometer is a useful tool in these situations as it can give a clue about the operation of the CVT.

Sometimes a baffle breaks off inside the muffler which could restrict the exhaust. Does any part of the exhaust system get unusually hot? This would be a clue.

This is a long shot - have you adjusted the valves yet?

[corneilius]

Hmm well, if the exhaust is getting hotter than it should I wouldn't know considering I have no frame of reference. But I can take the thing off and shake it around to see if anything rattles around.

I have done nothing with the valves, but I can look into it.

....if one would ask (not me of course), what would one do with the valves?

[sprocket]

Set the valve gaps between the rocker arms and the valves...

Here is a decent "HOW-2"



Looks daunting but after you do it once it is no big deal.. it is necessary part of maintaining these engines and cause lots of problems when the valves get tight...