Quadzilla XLC 500 Engine Issues

[Frank Angerano]

I don’t think that’s correct. The pilot jet is stationary and should be tight.   The air/fuel screw should be 2-1/2 turns out from a snug tight position and adjusted slightly in either direction to make it perfect while the bike is running. But should only be adjusted after the air filter and air box cover is back on the bike.  Just double check before you go tearing into it.  Also are you positive the carb is 100% cleaned properly? Only reason I’m asking is I’ve cleaned carbs over and over and somehow someway a pice of junk got back in.  Either form the tank or in the line someplace.  I also like fuel filters.   

Edited January 23, 2019 by Frank Angerano

[Zilla28]

Oh yeah I remember on a GoKart I use to have the pilot jet was all the way in tight. I just don't see the air/fuel screw on the damn carb. I will have to take another look.

I popped the top and bowl off and flushed it out with petrol and made sure all the jets were clean but didn't want to remove the floats or anything else as I didn't want to risk damaging anything.

[Frank Angerano]

Ok well I would watch a few videos on YouTube if I were you on cleaning or rebuilding an atv carburetor and in a half hour you will be a pro at taking them apart.  

Secondly if you haven’t seen the fuel/air screw it would be safe to say you’ve never touched it then ? If that’s true then it may be a simple adjustment to clear up the ping. 

[Zilla28]

Yes I have had it off and took the bowl off. I just don't see a brass adjustment screw that I can adjust while the engine is running. From what I have seen there should be a brass screw either on the side or on the bottom near the side that faces the engine but there is no screw just a brass plug thing with a pin hole.

I am not use to these carbs as I am only use to Walbro carbs on 2 strokes.

[Zilla28]

OK, I just found this.

Any idea how I remove the brass plug from mine?  I did try earlier today with some really strong wire but no luck.

[Frank Angerano]

Something does not look right on that carburetor.  There should be a jet inside that middle of the carb the main jet . Was it taken out? Also is that the factory carb the oem ? It looks like it’s a Mikuni 

Ok that looks better. I didn’t see the last pic. See the  main jet in the middle.  

The one you have the arrow pointed at is your air fuel mixture screw.   You have to get the right screw driver to fit in and uncrew it.   Was it tightened down all the way ?

if the brass plug is in there yiu have to get a small pick and pull it out.

Is that your carburetor or an image of another?

Edited January 24, 2019 by Frank Angerano

[Zilla28]

The image with the arrow is one I found on Google. The large photos are my carb and there are 3 jets inside the bowl, I had removed the one to clean it and took the photo to get the number of the other jet, so all is normal internally.

I will have to strip the bike..........yet again 🙄 to get the carb off and try remove the brass plug. Bloody nightmare lol

[Frank Angerano]

Lol I know brother.  Be patient.   You will get it squared away.  Get that plug out and be easy.   

[Zilla28]

I drilled out the brass plug and the jet was set to 105 minutes, not 150 minutes (2.5 turns out which is factory setting).

I adjusted it to 1.5, 2, 2.5 and 3 turns from closed position but still pinging slightly 😞 I am close to throwing the towel in now and getting rid of it.

[Frank Angerano]

I hear you brother as it can be frustrating.  Did any of the adjustments change how the bike ran ? Reason I’m asking is it should change the engine performance.  If the bike is running good at any one setting I would leave it there and move on to the next possable problem which leads me to my next question.    Are you 100% sure it’s a pinging your hearing and not something else? 

[Zilla28]

To be honest ive not felt any real difference in performance. The engine is coated with yellow clay looking crap from the previous owner and the floats in the bowl did have some yellow on so the only last thing I can think of is a bloody good strip down of the carb and a proper clean out.

[Frank Angerano]

I agree. It can’t hurt. You should see a difference in the engine with any little adjustment.   So tear it down, clean the as***** out of it.  Set the fuel/air screw at 2-1/2 turns and throw it back in.