hey new to the mini dirt bike, was just wondering i took all the air flow pieces out of my muffler and was told that i would be bad for my engine valves or something, was wondering if this was true or not? and i was told to lower some type of pin in the carb to help solve this prob need some pointers i got a 2007 or 08 (not sure) konker 90 without the stuff in the muffler it accelerates faster too and wasw wondering how i can make it go faster?
exhaust
- Thread starter luclml
- Start date
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A more open exhaust could do some harm because the engine could be running a bit leaner now. Yeah you could lower the clip on the needle (raises needle) to richen up at 1/2 throttle. But probably best if you try find a larger main jet (the one in the middle if you remove the float bowl). Might be hard to get jets for some little carb on your 90.
For a little more power, you would be looking at the carb (jets, air filter, or a new carb), and checking your valve clearances are 003 and 004 thou for intake and exhaust. Some pit bikes are geared way too low (revvy), if so consider a larger front sprocket.
You said it's a 90cc engine. So seriously if you want more grunt, then just bolt a 125 or 140cc engine in your frame. Hunt around. Maybe get something for about $200 somewhere. Larger and more efficient engine will mean ok power without needing to make it so figgin loud due to an overly open muffler.
ya i was thinkin of puttin a 140 in my bike and maybe just puttin on a better exhaust to give me more power but my only problem is finding one that will fit the bolt pattern, i was gonna go with one of the race 140 engines from konker cause thats wat kind of bike i got but dont know if that would be the best engine to go with dont really know if its a reliable company to go with? i wanted to c if i can go with another companies engine a better one
Sorry I've never heard of konker. But all pitbike engine mount bolts are compatible as far as I am aware. Can someone else confirm??
The Lifan 140 is good value. Unless you are straight line dragging all day, a well setup stock 140 will provide more than enough grunt for anything but the best handling pit bikes. If you get one then the most effective engine performance increasers are:
* Jetting and decent air filter.
* Usable sprocket gear ratio for your target tracks.
* Alum oil slinger - so it revs up much quicker.
* Fuelstar TM-VC ($30 device) in your fuel tank.
* Carb upgrade.
Forget an IRK or any ignition mods. Forget a big 28+ carb. I'm talking round bore carb sizes. Go for a 24 or at most 26 and focus on jetting.
Forget a loud exhaust if their is any chance you'll destroy riding options for yourself or others. I have a YZ250 muffler on my 150, and the power loss is minimal but the loudness drop is huge.
If that's not enough fun for you, then work on your suspension setup (basics like front vs rear heights and spring rates) then improve your forks and rear shock with at least new fluids or for the rear just buy a better shock. Most stock pitbikes handle bumps, corners, jumps etc, extremely *bad*!
wogtaz ryder
Well-Known Member
a 140cc engine will bolt straight into that bike with no problems mate
When you have the money, drop a 140 in your frame, do those basic mods/checks I mentioned (jetting, filter, gearing, slinger) and giddie-up and hang on. It'll be way different.
Repeating what I wrote earlier, assuming you are on dirt, and you are not dragging down straights, and don't have simply amazing suspension, then a well setup 140 has more than enough grunt for most pit bikes.150man
Member
hey wats this fuelstar TM-VC thingy do? where can i get 1?
It lets you get away with throttle abuse. You can run slightly rich jetting and get good throttle response, but you retain a crisp clean burn.
As a bonus it protects your valve seats. As a double bonus when the air temps or humidity get high, you wont need to lean off your jetting so urgently.
That's all based on my experience in my pitbike, my 450F. In case it matters, I always use 98 fuel.
I don't profit from their sales. No idea why they aren't better known. Been around for years.
Where: Try fuelstar.com NZ company.
