Anyone familiar with fiddy's?

[Fizzerbabe2]

I just went through and cleaned the realitivley new spark plug, air filter/screen, & cleaned the carb (other then the actual jet because I'm really not sure what is safe to put through the tiny thing, I had sprayed cleaner through it the best I could though...)

I did all of this because when I got it running, after sitting for a couple months, it ran really rough & choked out easily. After I have done all of this, I can't even get it started! Everthing is put back together right, brand new gas, clean/dry air filter...and yes, the fuel is turned back "on". You can hear the engine turn over, but it just won't start! After about 20 failed attempts...I gave up. I went from running rough to not at all with what should have made it run like a beast!

Any help?

[DonTZ125]

Ummm ... sure. What bike are we talking about?

[ragedigital]

Ummm ... sure. What bike are we talking about?

Little 50cc dirtbikes.... pretty popular here in the states.

[DonTZ125]

Ah. Thought that might have been it, wasn't sure.

If you've tried 20x to start - especially if this is a stroker - pull the plug back out to check you haven't fouled it. Is the plug cap on the plug? Is the plug cap firmly attached to the wire? Is the kill switch on? Is the mix ratio correct?

Is this a recoil start, or kick start? If it uses a clutch and gearbox vs a CVT, try push starting it.

[Fizzerbabe2]

If you've tried 20x to start - especially if this is a stroker - pull the plug back out to check you haven't fouled it. Is the plug cap on the plug? Is the plug cap firmly attached to the wire? Is the kill switch on? Is the mix ratio correct?

Is this a recoil start, or kick start? If it uses a clutch and gearbox vs a CVT, try push starting it.

I did check all of those things except pulling the plug out again...as far as the mixture goes, I have no idea how to tell if it's even remotely correct. When it was running rough I turned the screw until it ran good, then when I cleaned everything, when it did turn on the idle was sky high, so I dialed it down with the screw, but it died and won't restart again.

It is a kickstart, so no pop-starting it here...

I'll check the plug tonight after classes are over and the little one (child) is content...maybe I did foul it out when the idle was so extremely high...

[Kurlon]

Have you checked the valves yet? If the intake in particular is tight, you won't have any compression and it'll be a PITA to get running. Motor at TDC on the compression stroke so both valves are closed, you should be able to grab either tappet with your hand and feel it 'tick' up and down against the valve. If it's tight against the valve, it's time to adjust. If you don't have feeler gauges handy, loosen the lock nut, then adjust the tappet so that 'slop' is just taken up, back it off 1/6th of a rotation (you can use the lock nut as a reference, go from pointing at one flat to the next one) and then tighten the lock nut while keeping the tappet in place. You should now be able to feel the clearance. It's not accurate, but on those little motors it's close enough when they're stock.

Once that's done, mixture screw 2 turns out from lightly seated, throttle wide full open, kick it through. When it lights get ready to release the throttle. If it immediately dies, raise the idle speed half a turn and repeat the process. If it idles too high, just back it off.

Next ride the bike for a bit, get the motor good and hot and dial in the idle with it up to temp. Dial in your mixture screw as well once it's hot.

[~JM~]

Are we talking about a 4-Stroke or a 2-Stroke engine here?

First thing is to determine if you have spark or not. Pull the plug, re-connect it to the plug lead, then ground it out on the head & kick it over while looking for a nice fat blue spark. It helps if you are in a dark shed, garage, or at night, etc. The spark should make a fairly audible crack or snap type of sound if it is strong. Once you determine that you do indeed have spark, then you look at fuel delivery.

An old trick to try, is to remove the air cleaner & seal off the carb inlet completely with the palm of your hand, then kick it over a time or two. This will act as a choke, plus it may dislodge any pieces of junk that may be lodged in a fuel passage. Be aware that if the engine backfires through the carb your hand may get a bit hot. Then try to start the bike the normal way.

Those little Chinese bikes are notorious for carb problems & running lean when new. The carbs are crude & the ethanol in todays fuel eats them up fairly quickly.

Good luck
~JM~

[Fizzerbabe2]

You guys sure are knowlegable....I wish I had the mechanical aptitude on this one for the more in depth diagnosing...descriptions are awesome, but without having my lappy right next to me, I don't think I could remember what all to do! I'll probably try printing the page since my lappy's battery, or charger, is bad and has to be plugged in all the time!

Damned kids and Mid-terms have kept my little butt busy, so I havn't even had the chance to look at the fiddy again yet! Once my toddler gets done with this awesome strain of Strep, I'll get back out there.....