- Mon Aug 31, 2020 4:38 pm
#92626
Ive not had the bike long and to be honest I bought it with the intention of the carb mod. I took it for real blast on saturday, down the highway 36 . This is a 6 lane dual carriage way, if you are not doing 80kph you are in the way. It went pretty good actually but had obvious jetting problems. Its very poor at starting as I mentioned before and when at full throttle it will die, obviously the main jet or needle jet is way too small.
I got home and ripped it apart and looked up what others with a 500 had as jets sizes. Our host had posted some suggestions. The main jet was measured at 145 so I found a drill at 1.89 and drove it through.
The needle jet should be a PO which is 2.5mm + - ( care of Mikuni jet sizes on the internet) and 5 /64th was about right . Lucky eh?
Making a needle is easy --Mikuni give sizes of the needle at every 10mm B1 B2 B3 etc. Held in a drill is not difficult with a 80 grit to reduce the sized and finish with 600 to a mirror finish.
So with a tweak of the root canal drill on the idle jet it is just about perfect
An extremely lively motor with a seamless transition from coasting to throttle which the EFI could never do and did jerk and judder in a way that I found intolerable. I am extremely happy with the conversion and have very little more to say about it.
Did you know that when the low fuel light comes on you have approx 2 liters of fuel left. This is a warning that the fuel content in the tank is insufficient not only to continue with your journey but to warn you that the level of fuel in your tank is lower that the EFI pump will be happy with. I tested it today as I don't have a reserve, but then neither does the EFI.
Oh I also took out the inside of the silencer--it is now a straight pipe and is amazingly quiet. 97 decibels is the max allowed in Thailand and I don't think I am near that. I am hoping but yet pretty sure it will pass the annual inspection on emission too but i'lle let you know.
Right --thats it --im done unless there is any questions. Cranky out.
I got home and ripped it apart and looked up what others with a 500 had as jets sizes. Our host had posted some suggestions. The main jet was measured at 145 so I found a drill at 1.89 and drove it through.
The needle jet should be a PO which is 2.5mm + - ( care of Mikuni jet sizes on the internet) and 5 /64th was about right . Lucky eh?
Making a needle is easy --Mikuni give sizes of the needle at every 10mm B1 B2 B3 etc. Held in a drill is not difficult with a 80 grit to reduce the sized and finish with 600 to a mirror finish.
So with a tweak of the root canal drill on the idle jet it is just about perfect
An extremely lively motor with a seamless transition from coasting to throttle which the EFI could never do and did jerk and judder in a way that I found intolerable. I am extremely happy with the conversion and have very little more to say about it.
Did you know that when the low fuel light comes on you have approx 2 liters of fuel left. This is a warning that the fuel content in the tank is insufficient not only to continue with your journey but to warn you that the level of fuel in your tank is lower that the EFI pump will be happy with. I tested it today as I don't have a reserve, but then neither does the EFI.
Oh I also took out the inside of the silencer--it is now a straight pipe and is amazingly quiet. 97 decibels is the max allowed in Thailand and I don't think I am near that. I am hoping but yet pretty sure it will pass the annual inspection on emission too but i'lle let you know.
Right --thats it --im done unless there is any questions. Cranky out.
