Post by gearhead on Oct 4, 2013 21:50:44 GMT -5
So let me start off and say that I don't know a lot about scooters but I am definitely learning and fast. It all started 3 months ago when I bought my first 50cc scooter. It already had a big bore kit on it (100cc) and would climb to 50mph at full rev even with my 220lb frame on it. All was happy until it seemed to overheat one day (I normally take it on long 30+ mile drives about 1 time a week and avg about 12 mile round trip the other days -- which I never keep it max rev for very long on.) I took it to a shop and they said I had NO compression and needed to replace my cylinder, head, piston. Well as they were trying to overcharge me I decided to have them do the service but I provided the hardware and bought an 80cc big bore kit.
This worked very well and then I noticed a sputtering occasionally at high rpms and an occasional loss of power. I cleaned the carburetor myself and it stopped losing power but the sputtering continued. After about 2 days it stopped sputtering but then I lost power again. I change the oil every 500+ miles and I recently changed the gear oil (2 times now because I wasn't sure about it the first time
) because it was recommended at 3500 miles and my scoot has just over 4k on it. So trouble shooting all of these, today a new problem occurred and I am at wits end.
There is a whirring sound as if a belt is loose (I plan on taking the transmission case off on Sunday to check and see if I can identify problems with the clutch, variator, belt.
Actions that I plan on taking because I have no idea what could be wrong --
1. Replace CDI, Coil, and Spark Plug (NGK brand) -- I heard that the CDI could cause a loss of power and bad gas mileage which I have been noticing this week
2. Take off the cover for the clutch, variator, belt and inspect while running (if I can get it to idle and not die)
3. Check the valve timing (thanks youtube videos) because that may be causing part of the issue
Things I know ---
I don't have a lack of compression. After about 5 miles I can get back up to normal speeds but the first 10 minutes I can barely get up to 25 mph on max rev
My oil has been changed recently as well as gear oil
The Cylinder/Head/Piston are relatively new (less than 1k miles and yes I did the break in period for the first 400 miles)
There is a whirring noise that started today (if I can't resolve it based on your suggestions I will take a video on my phone and upload it as that might help narrow it down.. training all day tomorrow so I can't then).
I am at wits end and need my scooter to get to work on monday so I don't want to put it in a shop and would rather fix it myself
Thanks in advance
This worked very well and then I noticed a sputtering occasionally at high rpms and an occasional loss of power. I cleaned the carburetor myself and it stopped losing power but the sputtering continued. After about 2 days it stopped sputtering but then I lost power again. I change the oil every 500+ miles and I recently changed the gear oil (2 times now because I wasn't sure about it the first time
) because it was recommended at 3500 miles and my scoot has just over 4k on it. So trouble shooting all of these, today a new problem occurred and I am at wits end.There is a whirring sound as if a belt is loose (I plan on taking the transmission case off on Sunday to check and see if I can identify problems with the clutch, variator, belt.
Actions that I plan on taking because I have no idea what could be wrong --
1. Replace CDI, Coil, and Spark Plug (NGK brand) -- I heard that the CDI could cause a loss of power and bad gas mileage which I have been noticing this week
2. Take off the cover for the clutch, variator, belt and inspect while running (if I can get it to idle and not die)
3. Check the valve timing (thanks youtube videos) because that may be causing part of the issue
Things I know ---
I don't have a lack of compression. After about 5 miles I can get back up to normal speeds but the first 10 minutes I can barely get up to 25 mph on max rev
My oil has been changed recently as well as gear oil
The Cylinder/Head/Piston are relatively new (less than 1k miles and yes I did the break in period for the first 400 miles)
There is a whirring noise that started today (if I can't resolve it based on your suggestions I will take a video on my phone and upload it as that might help narrow it down.. training all day tomorrow so I can't then).
I am at wits end and need my scooter to get to work on monday so I don't want to put it in a shop and would rather fix it myself
Thanks in advance
..BAD TO THE BONE..
or #
main jet the Pilot jet probably is fine but you need more fuel after about 20mph.
main jet and stock IJ since it started and idled fine . Now on my 2T with a BBK it would start and idle but die unless I gave it throttle and had to adjust the idle speed often . I installed a larger idle jet and now it purrs . Check your float valve in the carb as it may not be keeping the bowl full . Do you give it any throttle to start ? On my 2T I had always give it just a sip 1/32 of a turn to start it but none with the larger IJ . Is it cold where you are ? You should always let any small engine warm up some prior to riding more so in the winter . With a new engine I would put on a fresh belt to be safe and keep the old as a spare . Stock head 40mm or a larger head ? If stock did it have an extra base gasket ?