Mike Cyanide
Well-Known Member
This post is for anyone who's needs alittle tuning help or maybe cold weather has complicated things for you.
Most believe that's jet and needle is the only tuning method for a bofeng/NT carb. This couldn't be further from the truth. There a few key tuning aspects completely over looked.
1. Float height
If your bikes acting weird. Especially if you have alittle angle to your carb float height is ofter the answer. Even if your skeptical of it or the symptoms vary. Some times you'll notice it's lean after a hard pull Especially up hill. Pull in the clutch and she revs alittle. Maybe your lean at lower throttle position and 4 stroking wide open. No your not crazy. ITS YOUR FLOAT HEIGHT! but Mike it's at 21mm it can't be... on my avenger bike it was at 15mm to run perfect. On my ld100 it's at 18mm. I don't care what you read on Google. FLOAT HEIGHT EFFECTS MIXTURE.
2. Oil ratios.
Can't seem to dial in just right? Maybe it got cold and your slightly lean or maybe since the cold you moved a needle position and it's just alittle too rich now but you don't wanna hurt it by moving it back in the cold weather. You pre mix ratio is the answer! I personally run 25:1 Dominator in warmer months but during the winter it's 32:1. No retuning and she's just perfect. This is a completely overlooked aspect of the perfect tune. STAY WITHIN SAFE RANGE! 20:1 TO 32:1 however if it seems just alittle too lean and you've exhausted options then 40:1 synthetic is fine. Running lean is much worse than 40:1 synthetic ever could be.
3. Spark plug gap and heat range
This topic is short and sweet. Once you found your optimal gap and range stick to it. Mine is .025 summer and .033 winter. Bpr6hs typically always.
4. Bonus tip. If you need to use rtv on these bikes EVER because proper seals are crucial use dirko HT red. It's specifically designed for just this application. You know it works because the label is in deutsche. I build saws also and all clam shell cases are sealed with this from the factory.
Here's some pics to checkout. I'm still relatively new to the hobby technically but with the help of uncle Damien and the rest of the crew in this forum I've built more than 20 motors and sold many motors and bikes! Here some pics to checkout. My motors my 2 favorite bike AND a very special peek inside the revenger! Im even gonna share the some secrets if you read this whole thing. Your looking at 190 exhaust and 126 transfers. The 3rd transfers open about 10° after with a 25° roof angle.. the primary transfers have 25° roofs and I've pitched them toward the intake instead of flat as stock. There are 2 base gaskets. This setup can work with the stock piston also. It's alot of blowdown I know but 12k is serious rpms. NOTE- this porting and timing is not for beginners this belly belly pipe is REQUIRED for this setup and port timings. These will not be optimal for side pipe or any other setup. I DO NOT RECOMMEND SUCH EXTREME NUMBERS FOR OTHER CASES. typically blowdown should not exceed 30. This took alot of time and testing. The third transfers are risky but on a regular avenger piston not so much. However I've run it quite a bit without a snag.
I Have this forum to thank for it all!
Now get out there and enjoy your precisely tuned motor!
Most believe that's jet and needle is the only tuning method for a bofeng/NT carb. This couldn't be further from the truth. There a few key tuning aspects completely over looked.
1. Float height
If your bikes acting weird. Especially if you have alittle angle to your carb float height is ofter the answer. Even if your skeptical of it or the symptoms vary. Some times you'll notice it's lean after a hard pull Especially up hill. Pull in the clutch and she revs alittle. Maybe your lean at lower throttle position and 4 stroking wide open. No your not crazy. ITS YOUR FLOAT HEIGHT! but Mike it's at 21mm it can't be... on my avenger bike it was at 15mm to run perfect. On my ld100 it's at 18mm. I don't care what you read on Google. FLOAT HEIGHT EFFECTS MIXTURE.
2. Oil ratios.
Can't seem to dial in just right? Maybe it got cold and your slightly lean or maybe since the cold you moved a needle position and it's just alittle too rich now but you don't wanna hurt it by moving it back in the cold weather. You pre mix ratio is the answer! I personally run 25:1 Dominator in warmer months but during the winter it's 32:1. No retuning and she's just perfect. This is a completely overlooked aspect of the perfect tune. STAY WITHIN SAFE RANGE! 20:1 TO 32:1 however if it seems just alittle too lean and you've exhausted options then 40:1 synthetic is fine. Running lean is much worse than 40:1 synthetic ever could be.
3. Spark plug gap and heat range
This topic is short and sweet. Once you found your optimal gap and range stick to it. Mine is .025 summer and .033 winter. Bpr6hs typically always.
4. Bonus tip. If you need to use rtv on these bikes EVER because proper seals are crucial use dirko HT red. It's specifically designed for just this application. You know it works because the label is in deutsche. I build saws also and all clam shell cases are sealed with this from the factory.
Here's some pics to checkout. I'm still relatively new to the hobby technically but with the help of uncle Damien and the rest of the crew in this forum I've built more than 20 motors and sold many motors and bikes! Here some pics to checkout. My motors my 2 favorite bike AND a very special peek inside the revenger! Im even gonna share the some secrets if you read this whole thing. Your looking at 190 exhaust and 126 transfers. The 3rd transfers open about 10° after with a 25° roof angle.. the primary transfers have 25° roofs and I've pitched them toward the intake instead of flat as stock. There are 2 base gaskets. This setup can work with the stock piston also. It's alot of blowdown I know but 12k is serious rpms. NOTE- this porting and timing is not for beginners this belly belly pipe is REQUIRED for this setup and port timings. These will not be optimal for side pipe or any other setup. I DO NOT RECOMMEND SUCH EXTREME NUMBERS FOR OTHER CASES. typically blowdown should not exceed 30. This took alot of time and testing. The third transfers are risky but on a regular avenger piston not so much. However I've run it quite a bit without a snag.
I Have this forum to thank for it all!
Now get out there and enjoy your precisely tuned motor!
