Not running to full potential

So today i upjetted my tomos streetmate from a 56 to a 58 because i noticed the spark plug was too white for my liking and after i did the chop its been running slower at middle/top end. can anyone tell me why this is, and if it can be fixed.

Re: Not running to full potential

did you change anything else before you changed your jet?

if not, then the reason it runs worse is because it's getting too much gas now. tomos knew what they were doing when they put that jet in.

Re: Not running to full potential

I remember when I first upjetted I was like "what the hell where'd my power go??" but hey man... go by the plug and logic straight up unless you want to soft / hard seize it one of these days... A leaner jet gives you MORE power, but is also likely not giving you enough lubrication / cooling... keep in mind these are air cooled engines for the most part so the air / fuel mixture is absolutely key. I would keep the bigger jet in if you want to be safe.

Now, as far as "fixing it" goes, you could get more air via pipe / filter upgrade which will mean that you can then upjet and have more gas AND more air so you'll still have a good ratio just MORE of both thus more power (unless you get too much of both). You could also change your gearing to gain back a little extra power either low end or top end whichever you are wanting to get back.

Good luck guy

Re: Not running to full potential

i am running a biturbo and 24 rear sprocket, also cut the little flange in my airbox to alow for more air

Re: Not running to full potential

next step is to go for a high flow air filter and a bigger main jet. no air restriction and more fuel flow is the goal. diid you drill the airbox before or after you upjetted?

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