I just got a two-year old JR 50 for my son. The previous owner said it would run great for a while and then not - so I got it cheap. After I got it home, I checked the plug and it's fouled. I'm fairly sure that's the only real problem. I've thought about disconnecting the oil reservoir and premixing the fuel -
Is there a better fix? And what's the best ratio?
JR50 mix
Started by
Ripmeister
, Feb 20 2006 02:31 PM
3 replies to this topic
Posted 21 February 2006 - 12:46 PM
Pull off the pipe and look for carbon in the pipe/silencer and at the exhaust outlet. These motors are well know for carboning up. Might even be worth pulling the cylinder off (VERY easy to do).
I'd leave the autolube on, run Motul 600. Great oil.
About a year ago there was a thread on KTMtalk in the mini section that talked about ways to improve the JR50, you might want to do a search there too.
I'd leave the autolube on, run Motul 600. Great oil.
About a year ago there was a thread on KTMtalk in the mini section that talked about ways to improve the JR50, you might want to do a search there too.
Posted 22 February 2006 - 01:32 PM
Same deal,,,used JR50 for son. Pulled exhaust, tried to look into cylinder with flashlight, exhaust port was almost completely clogged. Cleaned port. Blew air through pipe with air hose,,,almost no flow. Used torch to heat pipe (tap lightly with wood or rubber hammer,,careful not to melt hammer on metal you just heated with torch) got all kinds of black carbon out of pipe.
Much better,,,but still did not want to pull up hills. Did Internet search for performance mods,,,found out about 1st gear (bike is actually neutral to 2nd). Did the mod so now have 1st and 2nd.
Bike will pull itself through high grass or small hills now even choked up with throttle limiter so boy can only use about 1/4 throttle.
Great first bike. (After he learns to ride good,,,big sister will be getting a bigger trail bike and he will get her CRF50). I am going to keep him on "trail bikes" until he is at least 6 or 7 (only 3 right now).
Any ideas on next bike for sister,,,good rider, careful, not aggressive,,,9 years old. Been riding CRF50 since she was 5. Something equivalent to CRF50 but with slightly larger tires and much better suspension would be ideal. All trail riding maybe MX just 1 or 2 times a year (practice days, no races). Must be able to find used for reasonable price.
Much better,,,but still did not want to pull up hills. Did Internet search for performance mods,,,found out about 1st gear (bike is actually neutral to 2nd). Did the mod so now have 1st and 2nd.
Bike will pull itself through high grass or small hills now even choked up with throttle limiter so boy can only use about 1/4 throttle.
Great first bike. (After he learns to ride good,,,big sister will be getting a bigger trail bike and he will get her CRF50). I am going to keep him on "trail bikes" until he is at least 6 or 7 (only 3 right now).
Any ideas on next bike for sister,,,good rider, careful, not aggressive,,,9 years old. Been riding CRF50 since she was 5. Something equivalent to CRF50 but with slightly larger tires and much better suspension would be ideal. All trail riding maybe MX just 1 or 2 times a year (practice days, no races). Must be able to find used for reasonable price.
