Looking for assistance with performance mods. By catman25 (Read 1,066 times)

[catman25]

There is a ton of information. The issue is idk if the info applies to my bike. Just received my new scoot. It currently has 77 miles on it. Check plug and its tan ! Doing the gear oil change tonight. Changed engine oil the day I got the bike.
So far I have
1) added a tach. Currently it barely goes above 6k ( need break in or lighter rollers?)
2) on the way is a blue racing cdi ( seemed to help my old scoot )
3)added free flow air intake and exhaust and added a 125 main jet .
4) bought a #38 pilot jet ( have not installed yet ) * I need to tune carb unsure if I should add this jet ?
* that's about it but will add anything else I do.


Here is it now.

[katastruff]

A restricted CDI would rev at about 8 to 8.5k so you may need to tune your variator and clutch.

[catman25]

Next item I need to mod is the carb ! Of course there is no adjustment screw so need to get the plug out. Prior to getting the scooter I bought the next size up main pilot jet which is #38 . what should I look for to change the pilot jet meaning : would it def help performance or do u typically change it only if there is a issue ? See idk if I need it . if it helps acceleration then I want it . Also any tips on getting to the plug air mixture screw? Thanks for any help

[Alleyoop]

scooterdoc.proboards.com/thread/5807/plugged-fuel-ratio-screw

[catman25]

Another thought... original main jet is a 105 when I purchased my upgrade it gave 3 option 120 125 130 I picked 125 . but now I read people saying you should upgrade jets 2 spots for each mod so 2 for free flow air and 2 for free flow exhaust. So should I look for a a 109 -110 ?

[catman25]

I am 722 feet above sea . thanks alleyoop always helping thanks

[Alleyoop]

Yes, 110-112 would work well, ones that say 125 130 are way off that size is for BBKS mind you I have a 62bbk with a 60mm stroker crank and it only takes a 122.5 main jet a 125 is to rich and it has a #38 Pilot jet from a #35. People always think dump a gallon of gas and it will tear up the asphalt but in reality the motor is making less power for being overly rich.

[catman25]

Sweet . yeah I'm kinda stuck at either drilling the 105 up to that size or stay with the 125 for a while. If I had to drill to 110-112 what size drill bit to use lol ? Should I stay with original pilot or throw in the 38 ? Currently has a 36

[catman25]

Found out my pilot jet is a 32. I ordered a 38 thinking it had a standard 35. So I thought 32 to 38 was to much of a jump . chose to keep 32 in . I took my 105 and pick up a drill bit set. Drilled it with 1.11. After I drilled it ,it is somewhere between a 110 (1.11) to a 1.16 as that dril bit was the next size and didn't fit. I attached carb back together . drilled the cap out for the air mixture . I counted 2 turns to close the nozzle then forgot if they were real full turns or if they were really. 2 1\2 turns. Did 2 half turns out and starts fine ! Seems snappy ! Brought idle slightly up to @1500 . taking it for a test now.

[Alleyoop]

Good job,
Alleyoop

[catman25]

Got it set good accell wise. . has a good pick up speed. But hollow sounding and starting popping and running crappy at wot full speed. Then come to s a stop it stalled ! Hahmmmm. So thinking I should drill next step bigger? Idk. Any suggestions ?

[Alleyoop]

Here is the thing IF it is popping at wide open throttle IT IS VERY RICH and also why it dies coming down to idle it keeps on dropping flooding the plug out.

Sorry but you drilled the main out to much, now you need to make is smaller or you can try allowing more air in and see if that stops it from popping at wide open throttle.

Now coming down to idle if you have the #38 in go down on the pilot jet #38 lets a lot of fuel in.
Alleyoop

Sounds a motor makes will tell you what it needs:

scooterdoc.proboards.com/thread/8628/motor-sounds-tells

[jct842]

Get out your soldering iron and solder the too big jet shut. Then drill it again but not so big! If you don't have the right size get to a welding supply, they carry bits for redrilling torchs. They are cheap, sets run maybe 10 bucks and cheaper on the net.

[catman25]

The upgrade jet I bought. Was a 125 and it ran ok just not much for performance. The hole on the 125 is larger then the one I drilled out. So I'm not sure how it could be too rich ? My thought was it was starving for fuel at wot . so maybe popping wasnt right. Hesitation definitely !!!

[jct842]

Then there is the thing about fuel starvation at WOT. Have had that happen on a 150, fuel pump was not pumping enough, and soon as you back off all is well. Vacuume at WOT is not as much as at lower throttle.