Just picked up this 99 rm80 for my grandson and the guy said it had been bored out to a 110. Said it ran great was using 32/1 fuel mix. I brought it home and found it wasn't running great, it was boggy at part throttle, did I some research and ckd a few things. I pulled the rod #39 out of the slide to see where the circle clip was. It was on the second lowest notch, so I dropped it to the last one figuring it needed to be richened up. Float was high so I reset that and ckd the main jet for size, it is a 012. I got it back together and first kick fired right up, idles great, warmed it up then went to the air mixture screw. it was at 2 turns out. I started to turn it in and I could tell the motor was getting rich quick so I went to 2 and then 2.5 Sounded pretty decent took it out for a spin, ran much better, most of the bog was gone but it didn't really want to go at full throttle,pumped out a lot of smoke, telling me it was too rich on the top end. So here is my questions...How far can the mixture screw be turned out before it wont stay in. Can i go 3-4 without it falling out when im riding.Should I decrease my main jet by a number or pull the rod and go back on that notch. I can figure it out but was hoping for a carb guru to help me hit the nail quicker. Thanks for any help and letting me join!
Suzuki carb tech questions.
- Thread starter dlw6767
- Start date
http://www.iwt.com.au/mikunicarb.htm
Set the float, idle, needle, main. In that order.
If the screw is further out than 3 turns or less than 1 turn, it requires a different idle jet.
-BIG DAN
Set the float, idle, needle, main. In that order.
If the screw is further out than 3 turns or less than 1 turn, it requires a different idle jet.
-BIG DAN
Big dan is right. No more than 3 turns.
Easy things first. Clean that carb twice then clean it once more. Clean the plug and then give it another try. If it's a supermini kit then more than likely you need better gasoline as well. If you have an airport nearby and can get 100ll use that. If not you'll need to go get some VP race fuel. C12 mixed at 50/50 with pump gas will keep that motor from detonating on ya. Good luck.
Easy things first. Clean that carb twice then clean it once more. Clean the plug and then give it another try. If it's a supermini kit then more than likely you need better gasoline as well. If you have an airport nearby and can get 100ll use that. If not you'll need to go get some VP race fuel. C12 mixed at 50/50 with pump gas will keep that motor from detonating on ya. Good luck.
If it was mine I would be really interested in what actual size the piston is. 110 is not a common size. It usually takes stroking to get an 80-85 that far.
Usually when you overbore one, if the compression and squish is adjusted as well as port timing the rig will take smaller jets to achieve the air fuel mix just based on the displacement increase. All assuming the carburetor stayed the same size.
I have seen some of them (125's for the most part) that needed to be jetted way up to prevent detonation and the seizures and preignition that can follow. That happens if the head work isn't done along with it, and one of the reasons that people who have owned big bore kits use race fuel. (that in itself is not always a cure all if the machining wasn't done right.)
Usually when you overbore one, if the compression and squish is adjusted as well as port timing the rig will take smaller jets to achieve the air fuel mix just based on the displacement increase. All assuming the carburetor stayed the same size.
I have seen some of them (125's for the most part) that needed to be jetted way up to prevent detonation and the seizures and preignition that can follow. That happens if the head work isn't done along with it, and one of the reasons that people who have owned big bore kits use race fuel. (that in itself is not always a cure all if the machining wasn't done right.)