Im wondering what to do with the spare px125 engine Ive got sitting in my shed once I replace the blown oil seal and main bearings. I also suspect the barrel and piston are knackered so I was thinking about doing a modest tuning job on it by fitting a DR 177 or polini 177? cylinder kit and a sitoplus exhaust. My budget is low, so is it very necessary to fit a larger carburettor i.e 24/24 SI or can I get away with the standard px 125 SI carb and upjet?
If this can help, ive been riding for two years now with this set: DR 177 kit , racing crank , T5 24/24 carb and a Pitone. Ive been last year to Holiday in Holland, doing 2000kms in a weekend without any troubles. My engine and the DR kit were at the time 6000km. Im still riding the same engine with now 10000kms. If there is one thing that im sure is that DR kits are strong, have torque and well made but they are not the top tuning kits (a friend of mine got the same kit with HP4 flywheel, racing crank, polini 23/64, 28PHBH carb, boost bottle and SIP perfomer exhaust for 4 years now and he`s also trouble free).
If I were you, I would prefere the DR177-kit with the standard carb and standard exhaust. Further you will need a Bosch W4AC spark and a 108 main jet. This a very cheap and reliable tuning for your P125!
Sorry but no you can`t. You will have to change it, the best one i can think of would be a T5 carb with jetting to match the kit. May i suggest steering well clear of DR kits, in my experience they are nothing but trouble, i have a DR180 10 port kit with full ported casings and reed valve and i have had nothing but trouble with that arsing kit. The best kit i could suggest would be the 166 kit by either malossi or some one of similar standing. It will still perform reasonably well even with a sito plus.[:drink:] [:drink:] [:drink:] [:drink:] [:drink:] [:drink:] [] [] [:smokin:] [:dance2:] [:D] [:D] [[:O]] [:D]
I dont know about the DR but with the 177 you can definitely get away with using the standard carb. In fact you dont even need to change the jet (this is confirmed in the fitting instructions). I have a Polini 177 on my Sprint (virtually the same engine as PX125) and it hasnt given me any probs and I have done over 3000 miles on it now. Im also using the standard exhaust. It is worth doing the porting to the casing that is recommended in the instructions. You`ll need a Dremmel or similar to do this job.