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Yet another Carb problem. Again non Cr5...

Posted: October 26th, 2008, 8:25 pm
by Travis
Ok, so apparently my 20 year old CR 500 is the best vehicle in the garage. I had left my 400ex sitting since I aquired the bike. The wife had been riding it a little and about 2 months ago tells me it will not start. I went outside to check it out and sure enough something was wrong. I immediately thought it was the carb as I had previously had trouble with it wanting to constantly overflow and flood to death. I had cleaned the carb wice before and this fixed it for a month or so. It was flowing again and it wouldn't start. This was my first thing to fix.

After cleaning it out. and putting it back on the thing still would not fire. This time there was no overflow and apparently no fuel what so ever. So I immediiatey flew mad cursed a while and then put it up.

I have now let it sit until today. Angry with the Golf cart I decide to work on the quad a little. I pulled the carb again to give it the go through again because the thing would only fire if I hold my hand over the back of the carb and totally cut off the air. So I took it off and get to thinking since my XR 400 needs rebuilt and the kicker is stripped I would pull it's carb and use it.

I get the carb off the XR and use it with the twist throttle. Pretty sweet, fired right off. Ran great unless you just open it full throttle real quick and then it falls on its face. Almost dies when you do this. I think maybe because it has been sitting for a wile so I ride it up the road. At wide open throttle it pops and cracks and runs like crap.

So I wheel it back into the Garage to see what may be up and this carb is pouring out the overflow too. :shock: I have no idea what is up. There was nothing wrong with this carb on the bike. The only time it would flow was if the bike was laid over. Can you guys tell me what I am doing. I know the jets are wrong for the EX because the bike was stock and the quad has the 440 kit and a K&N but it shouldn't overflow. I know the first thing to check would be the fuel because they are the same for both carbs but I filled it up from the same place as the bike on the same day.

Give me some suggestions before I take my carb to the shop and end up having to pay someone to fix it. The carbs are totally different by the way. In case anyone was wondering. The bike one is much smaller though and makes more room in the quad. Not smaller on the openings but smaller overall.

Posted: October 27th, 2008, 12:53 pm
by ISBB
pouring out the overflow is usually a float issue.. and no fuel is usually a float issue... sooooo check your floats..

as far as the xr carb falling flat on its face when smacked wide open.. i got $.20 that it has an accelerator pump on it thats setup stock like and they are known to do that.. there are a few mods to take care of that dreaded bog.. :D I learned to ride with it on my 426 it didnt really bother me and was usually only affected at idle to wide open which when your riding your not really idleing anyhow. :D

Posted: October 27th, 2008, 10:54 pm
by Travis
What gets me is they are both having float problems. And the XR carb didn't on the Bike. I don't know I guess I will pull it apart and check it out. Why is it that every single screw in these carbs wants to strip when you take it apart?

Posted: October 28th, 2008, 3:48 pm
by iggys-amsoil
To many beers?

Posted: October 28th, 2008, 3:51 pm
by Exnav
iggys-amsoil wrote:Not enough beers?
Fixt :lol:

Posted: October 28th, 2008, 4:42 pm
by BIGGDAD
ISBB wrote:pouring out the overflow is usually a float issue.. and no fuel is usually a float issue... sooooo check your floats..

as far as the xr carb falling flat on its face when smacked wide open.. i got $.20 that it has an accelerator pump on it thats setup stock like and they are known to do that.. there are a few mods to take care of that dreaded bog.. :D I learned to ride with it on my 426 it didnt really bother me and was usually only affected at idle to wide open which when your riding your not really idleing anyhow. :D
THE OVERFLOW ISSUE COULD ALSO BE A NEEDLE/SEAT PROBLEM. IF THE BIKE IS OLDER OR HAS BEEN SITTING, THIS IS MORE LIKELY. LOOK FOR A GROOVE IN THE NEEDLE/SEAT.