Jump to content

Got my son's stolen xr80 back. Now I need to know the factory settings for the adjustment screws.

Recommended Posts

My son's 2001 XR80R was stolen, and the police recovered it. It was found in a nearby city, on the side of the road. Apparently in a part of that city it's a popular thing for people to ride around on stolen dirt bikes, even though there are no trails. The cops said they recover a lot of dirt bikes. Now the fuel leaks from the carb through the air box. I was able to get it running for about 5 seconds, but then I didn't give it enough gas to stay running, so it stalled and then started leaking gas soon after. I'm guessing what happened was the guy who stole it adjusted something wrong, got it to run, took it for a ride down the road in a nearby city, then stalled it, and couldn't get it started again. I can't see any damage to the carburetor, so that's why I think it was something adjusted wrong, though I don't know why he would have messed with the settings. It was running fine before he stole it. I figure I should start with setting the carb mixture and idle screws to the factory settings, but I can't find on the internet what those settings are. Any help would be appreciated.

Share this post


Link to post
Share on other sites

Ok. So the idle or mixture screws wouldn't cause fuel to keep flowing slowly? The theif/s only had it for 1 day before the cops found it. It ran fine a few days prior to the theft. I wouldn't imagine corrosion to cause the problem so quickly, but anything's possible. I just hope they didn't screw the bike up. I had a can of 2-cycle gas that was locked to the bike in the back of my pick-up truck, and when they cut the locks they stole my gas can too. I wasn't sure if they poured the 2-cycle gas in the xr, but I didn't think it would matter much, except make it smoke, and maybe foul the plug. Could 2-cycle gas mix do any harm to a 4-cycle bike?

Edited by Jay Is Jay

Share this post


Link to post
Share on other sites
57 minutes ago, Jay Is Jay said:

Ok. So the idle or mixture screws wouldn't cause fuel to keep flowing slowly? The theif/s only had it for 1 day before the cops found it. It ran fine a few days prior to the theft. I wouldn't imagine corrosion to cause the problem so quickly, but anything's possible. I just hope they didn't screw the bike up. I had a can of 2-cycle gas that was locked to the bike in the back of my pick-up truck, and when they cut the locks they stole my gas can too. I wasn't sure if they poured the 2-cycle gas in the xr, but I didn't think it would matter much, except make it smoke, and maybe foul the plug. Could 2-cycle gas mix do any harm to a 4-cycle bike?

No it will be fine,just smoke  and possibly foul a plug.

Share this post


Link to post
Share on other sites

Pull the carb apart. If he stole the bike, it's likely he stole whatever gas he could get his hands on and there's probably all sorts of crap floating around in your float bowl. Be a good idea to flush the tank also. 

Share this post


Link to post
Share on other sites

I have two XR80s as pit bikes, a 2000 and a 2005.  They both idle perfect and run well at 2.5 turns out on the idle screw which is the bigger one centered on the carb and 1.75 turns out on the air screw which is the smaller screw in the bottom left corner. 

 

I'm with the other posters though, after being stolen you should take the tank and carb off and clean them out.  They could of put dirt in the tank or God knows what.  Mixed 2 stroke gas is not the problem, it would run fine with it just smell good. 

Share this post


Link to post
Share on other sites
11 hours ago, 1320fastback said:

I have two XR80s as pit bikes, a 2000 and a 2005.  They both idle perfect and run well at 2.5 turns out on the idle screw which is the bigger one centered on the carb and 1.75 turns out on the air screw which is the smaller screw in the bottom left corner. 

 

I'm with the other posters though, after being stolen you should take the tank and carb off and clean them out.  They could of put dirt in the tank or God knows what.  Mixed 2 stroke gas is not the problem, it would run fine with it just smell good. 

The bike runs again!

I drained the tank and the fuel didn't look blue at all. But just to be safe I replaced the gas. I pulled the plug, and it was a little oily and coated with carbon. I dried it, then took a piece of emery cloth to lightly rub the carbon off the spots were the spark would happen. Replaced the plug. Then pulled the carb. I noticed right away that a small piece was bent and cracked which partly guides the pin. I carefully tried to bend it back, but it broke because it's aluminum. I decided to JB Weld it. Worst case scenario is it doesn't work and I have to buy the part anyway. It's a part with virtually no stress, so I doubt it will break. (The bike ran fine, then the bike stopped running soon after the theft. My wild guess is the thief dropped the bike on a perfectly placed rock and damaged the carb just enough to make it stop running.) I just hope the very slight change in shape from what it would have been originally won't matter enough. Then I completely took the rest of the carb apart, cleaned every piece and put it back together. Before reinstalling it, I played around with the throttle cable to see how the pin moved. The pin seemed to move smoothly and not get hung up. So I installed the carb, and now the bike runs again! I do however still need to adjust the screws on the carb to make it run a bit better. So the advice about the 2.5 and 1.75 turns is a helpful starting point. Thank you.

Edited by Jay Is Jay

Share this post


Link to post
Share on other sites

I replaced the sparkplug. The old one was very black and the spacing was wider than the new one. The we turned the fuel on, and immediately began trying to start the bike, just in case it stopped working because of flooding. At least it might start at first. It did start, and it seemed to idle on it's own for a minute. But then it stalled, and we couldn't get it started again. Also, we noticed fuel leaking slowly from the carburetor. We couldn't tell from where, but it was the lower half. At the very highest it may have leaked from, it would be the lowest part of the plastic intake tube, which I had forgotten to tighten down with a screw.

So I removed the carb yet again. Brought it home, and took it all apart looking at everything. Still, the only think noticeable is the JB Welded tab that basically makes it so you can't put the top of the carburetor on incorrectly, and it's the part that the cable goes through for giving throttle with the hand adjuster.

When taking it apart I noticed some very tiny holes in a return tube. The tube hooks to the bottom of the bowl, and also up at the area where the air intake/mixture out, goes. I also double checked that the needle valve was as straight as I could tell. It seemed fine. I fixed the holes simply buy cutting off the half inch of tubing, as the tube was much longer than necessary.

But originally the problem was that so much fuel was flooding the carb that it was flooding backward through the air filter. I wonder if I just keep solving minor problems that wan't really make the bike run. Idk. Sorry, I'm just getting frustrated. The thief should be required to pay for the repairs. But he just got a fine of a few hundred dollars, and some community service.

Share this post


Link to post
Share on other sites

What are you doing?

That long tube with holes is supposed to be there.

 

You just need to fix the float needle assembly that is what causes the float bowl to over fill and then leak.  Nothing else will cause the flooding.

You have a float needle, a needle seat, and a cavity that the needle valve slides into. The cavity needs to be polished clean, the float needle needs to be polished clean and it's rubber tip must have no wear marks your you must replaace it. The seat must be free of any pits, or you must replace it. On some models there is an oring under the seat, and it goes bad and must be replaced. Do not try and do this yourself, take it to a pro.

Now set the float level to factory specs, usually that is 20mm 

http://www.allthingsmoto.com/forums/f-19/2002-xr80-float-height-31232/

 

 

You adjust the height by bending the 'tang' that touches the needle valve. Just touching, not depressing.

 

Edited by THE KRAN
  • Like 1

Share this post


Link to post
Share on other sites

Thank you Kran. That was very helpful. After taking it apart multiple times and trying to inspect everything, and blowing air through a tub into various ports, I could not understand how the problem could be anything other than the float valve. But it looks undamaged, and I see no scratches where it seats. So I couldn't understand why I was able to blow a tiny bit of air through it even when it was supposed to be closed.

My plan was to try to add the tiniest bit of oil to the rubber part, then lightly wipe it dry. I figured that may give it a better seal. I'm not so sure if that would be a waste of time though.

I will probably end up  just ordering a new float valve and hoping to polish the seat.

Thank you again for your post. It was very helpful.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:


×