Posts
3
Joined
5/18/2020
Location
Ormond Beach, FL
US
Edited Date/Time
5/20/2020 4:13pm
Disclaimer, I’m a complete novice and so is my son. He turned 11 in January and he’s kinda small for his age. I bought him a CRF80 for Christmas, and I’ve been taking him to the local Mx track almost every weekend. Then I got jealous and got an older yz250f to ride with him. We are really enjoying ourselves. So a couple of days ago I surprised him with a yz65 so he could be more competitive at the track. We took it to the track and he loves it! I couldn’t be happier. So I’ve been researching the bike and there’s really not allot of info out there. 90% of what I see is professional magazine reviews, Not regular owners. What are other yz 65 owners thoughts on the bike. How often are you doing top ends? Should I buy a compression tester? What oil ratio? I’m running 32-1 with yamalube2R. I’m getting black stuff coming out of the exhaust. Should I run a hotter plug to combat this, or less oil, or smaller pilot jet? With the clutch pull being so light are the clutch springs too light? Are people burning up clutches? Sorry I’ve got so many questions, I’ve actually got a bunch more but Ill stop there. If there are any other owners out there that wouldn’t mind chiming I’m with there experience on some of these issues I’d appreciate it. 
1) A hotter plug
2) Leaner jetting (move the clip upward on the needle jet and / or get a smaller main jet)
3) Less oil in the gas (higher ratio). I'd be wary of this one, as little engines tend to like more oil.
Yamalube R at 32:1 is probably just fine on that bike. If I were you I'd start with a hotter plug, one size smaller main, and lean out the needle one position on the clip. Check the spark plug often and keep making incremental changes to leaner jetting until the plug is a nice brown color.
EDIT: Further info: I would not change the pilot jet on that bike unless it has idling problems. Your rich condition is probably caused by the main jet and mid-throttle openings, not by the slow circuit which is controlled by the pilot.
Also remember any changes you make which lean the bike make it more susceptible to seizing if the conditions get cooler, drier, or lower elevation; or if your rider gets significantly faster. Don't worry too much though; the OEMs jet their bikes a little rich from the factory on purpose.
The Shop
We ran Yamalube 2R at 40:1 Never an issue with this oil and piston and rings always look great.
Motul transoil expert 10W40 for gearbox.
Splooge unless fouling plugs I wouldn’t worry about at the moment until your kid starts hammering down. You’ll find it will correct itself with your kid getting more aggressive on the throttle.
We had the KTM65 and were one of the first to get the YZ65 and wouldn’t hesitate getting one over the KTM65 again. The advantage (racing) with the KTM is there is a lot of info and aftermarket products out there for it but it is a maintenance heavy bike compared to the Yamaha.
I only cleaned the PV on top end maintenance.
With the suspension find someone with experience in dealing with the YZ65 suspension as if i remember carefully its not only the spring they should change but the valuing as well. I’d “guess” my kid was around the 63-66 lb mark
Leaner pilot, main and likely needle adjustment necessary. Its not difficult and will make all the difference.
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