cg125br-j cafe build/ conversion. Are We There Yet?

[crazypj]

lifting needle makes it richer
You may be able to shorten pipe another 4"~5" to bring outlet closer to axle although where you are now could be close to optimum, I don't have a lot of experience with modified CG motors

 

[tom050162]

The actual baffled section inside the pipe exits probably around an inch short of the rear cone on the end where you can see the screw holes is the end of the pipe, the end is just a piece you can take off its just to tidy up the pipe.

 

[tom050162]

Well unless its going down a hill, the speedo doesn't seem to crawl any further than 55, Even after shortening the exhaust it still seems to be lacking top end in anything past 3rd gear it wouldn't rev up and I couldn't tell you what rpm range its actually stopping at seeing as the engines were never fitted with a tacho!

 

[tom050162]

What would this be like if I cut the pipe off another few inches? Would it free up the top end power a bit more as it just completely ends at 50-55?

 

[tom050162]

Just fitted the exhaust correctly by making up a shim for the joint on the pipe then drover the muffler on with a hammer and wooden block.
Sealed it tightly and the exhaust is now on properly, not sure if it will come off at the moment though,

On the plus side I changed the gearing, swapped the front sprocket out for one off an older cg125 (1974 I believe) and the top end has livened up a lot, the bike feels much quicker and pulls up over 55 easily not had a run to try it all out to see what it is capable of but also fitted a proper K&N and that's vastly improved the mixture and also idle.

Going to try and experiment with lengthening the distance of the filter from the carb by adding a section of PVC pipe in before to hopefully straighten up the air flow acting like a velocity stack, More to be done made a baffle in the exhaust to give a little back pressure see if it helps.

That's all folks.

 

[tom050162]

Here's how she stands at the moment!

 

[tom050162]

Just found a suitable engine a 150 Chinese engine under the brand 'champ' for a measly sum of £10 and a listed good compression if all goes to plan and I win the engine ill be picking it up at the weekend and see if I get a little more power from this one