Motor bogging at start up low speed

[AaronF]

When i turn the engine on the motor bogs pretty bad making terrible vibrations through the whole bike.Not sure what could be causing the bogging,i just cleaned the carburetor filter and put on a new fuel line/stock air filter.I've adjusted the idler screw numerous times an it still bogs.Any suggestions to this?Thanks

[GearNut]

What kind of engine setup?

[AaronF]

Originally Posted by GearNut

What kind of engine setup?

Totally forgot to say what kit i have,sorry bout that.I have the 2 stroke 80cc=66cc engine with all stock gaskets filters etc.

[GearNut]

Bogging could be an intake air leak, air leaks at the crankshaft seals, plugged up exhaust, choke left engaged, rich fuel mixture, bad gas. There are alot of variables. What color is the sparkplug? Black, white, or tan. The color can tell you alot concerning what is happening inside the combustion chamber.

[AaronF]

I will check the spark plug here soon and let you know the color of it.I also forgot to mention,i just installed this new kit two days ago with 40 miles on it already.Note that when i mixed the gas/oil i don't have a gas measuring cup,so there for I'm not sure if the correct amount was used for the first tank,the ratio is supposed to be 16:1 The carburetor was clean as clean gets,i just cleaned the float bowl as well.It seems as when I'm not using the throttle,the idling is pushing me down the road at 10MPH witch is weird..

[DonnnN]

Originally Posted by AaronF

I will check the spark plug here soon and let you know the color of it.I also forgot to mention,i just installed this new kit two days ago with 40 miles on it already.Note that when i mixed the gas/oil i don't have a gas measuring cup,so there for I'm not sure if the correct amount was used for the first tank,the ratio is supposed to be 16:1 The carburetor was clean as clean gets,i just cleaned the float bowl as well.It seems as when I'm not using the throttle,the idling is pushing me down the road at 10MPH witch is weird..

You're Not Twisting The Throttle And It Goes 10MPH? Wow How Far Have You Unscrewed This ? (See Pic)







The More You Unscrew That The Engine Will Rev MORE.. And Adjusting The Idle Screw Won't Work..
So Try That First.. ; ) Hope I Helped

[AaronF]

The only thing i have tried is messing with the idler screw,i have not tried the throttle twist yet and personally i didn't know it did anything!I will give that a try in the morning and post with the results.By twisting it up/down what exactly does that do?Give more speed/performance?Thanks!

Strangely yes it does push me along at 10MPH without throttling,i was kind of amazed at that but i do know its not supposed to do that lol.

[AaronF]

I would also like to know some modifications that can be done on the cheap for better performance.Such as a cheap muffler,carburetor air filter etc. any suggestions websites would be great,Thanks!

[BarelyAWake]

Well, firstly the idle set screw adjusts only the idle, it does this by limiting how far down the slide can go, thereby allowing more or less fuel to the engine - but only at idle. So while you do need set this (engine off, screw it in all the way gently & by hand - then back it out 3 & 1/2 turns for approx idle speed, then fine tune w/engine running) it wont do anything for a fuel/air adjustment. That is the small C-clip on the needle inside the carb - usually the second slot down is the average setting - but every motor is a little different, always check plug coloration when messing about with your fuel/air ratio.


Just wanted to mention that these china 2 strokes are renowned for running like crap until broken in. Mine was 4stroking (misfiring every other stroke) so bad for the first hundred miles or so despite all attempts at adjusting fuel/air that I considered junking the dang thing.

Now that I've got about three hundred miles on it - it's a night and day difference. I'm not suggesting that you shouldn't attempt to tune it in, I just wanted to reassure you that it isn't just a matter of mix - ya gotta ride the thing till ya bleed!

Spookytooth, Bikeberry, Sick Bike - most of this forum's sponsors are quite good if yer lookin for upgrades btw, and the performance subforum here is ossum I would actually suggest replacing the carb with the following as the 66ers carbs are garbage;

CNS Aftermarket Carburetor for Motorized Bicycles w/ Adjustable Air-Fuel Screw (air filter, cables, grip & kill inc) Price: $50.00

Spooky Tooth Cycles - Motorized Bicycles: Gas Powered and Electric Bikes - CNS Carburetor for Motorized Bicycles

Cheap muffler? I suppose you want an inexpensive tuned pipe... Though I don't much like the Machiavellian method or the various plumbing fixtures, this setup is one of the least expensive (also available in chrome);
Black Expansion Chamber Exhaust Pipe [SBP-ES002] $64.95 Sick Bike Parts

however - for the money, this 'un is soooo sexy;
New SCSW Tuned Pipes for sale! $120 Pipelyne Manufacturing. (408) 279-2307 http://motorbicycling.com/f23/new-sc...-sale-189.html


Hope this was some help - just remember to get some miles on yer bike, not that it's much of a chore heh

[Bikeguy Joe]

Originally Posted by AaronF

I will check the spark plug here soon and let you know the color of it.I also forgot to mention,i just installed this new kit two days ago with 40 miles on it already.Note that when i mixed the gas/oil i don't have a gas measuring cup,so there for I'm not sure if the correct amount was used for the first tank,the ratio is supposed to be 16:1 The carburetor was clean as clean gets,i just cleaned the float bowl as well.It seems as when I'm not using the throttle,the idling is pushing me down the road at 10MPH witch is weird..

A couple of notes-

16:1 is TOO MUCH OIL! Go to 24:1.

10 mph at idle? I think that's about right..below that you should have the clutch in. If it revs up with the clutch in, turn down the idle, or check for an air leak at the manifold to cylinder junction.

Get a measuring cup, or use the side of the bottle of oil where it is marked for oz. increments....never just "guess" at the engines life blood. (oil)