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xr650r carb problems about to just sell bike


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I have a Honda xr650r that i bought. I converted it to street and it was running perfectly for 3 months. Fuel started pouring out of overflow one day but it would still run fine. It was intermittent and when it was pouring out of overflow, it would drain the tank if stopped, but if I was riding it wouldn't leak so it was just at stoplights and when starting it. Also, she had always started first or second kick, no choke needed since I'm in hot Texas. Other times, I would open the petcock to start bike expecting it to leak but it wouldn't, next day it would overflow.. you get the idea. But other than that, it ran perfectly.

I rode fine for a few more weeks and then I rebuilt the carb using the same settings. 68S pilot, 175 main, B53 comp needle. I noticed several of the screws were stripped, gaskets were bad.. so I got on partzilla and ordered all new internals for the carb. But all the parts were the same OEM parts that i was replacing. I also replaced the entire petcock assembly and fuel filter (also OEM). However, now it will not start at all. Not even a whimper. It is getting a spark, compression is good. Have tried for 2 weeks. Fuel is also still pouring out of the overflow which is what prompted me to rebuild it in the first place. The float height is what is should be but even when I adjust it to where it should be shut off, it will still pour. I havent changed the tang on the new OEM but Ive been experimenting using the old float setting different heights and it has fuel poring out when set at 25mm and when I go the opposite way to 8mm, so it doesnt make sense. The needle and needle jet are not jammed with trash as I replaced those parts as well and have verified everything is clean.

I wish I would have gotten a new 2019 XSR900 but Ive already spent so much money converting this to sumo and upgrading suspension and rebuilding other areas of the bike. Im about to just sell it and cry because I feel utterly defeated.

pics to show example of my work. Also tried attaching them to this post

https://imgur.com/a/S2PFlV9

 

Im pretty meticulous and exacting which is why Ive never had anything like this happen. Any Ideas?

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Either the inlet valve is worn or dirty or the float is stuck .


Did you replace the inlet valve ?
With the carb off the bike if you turn it upside down you must hear the float closing .
If you blow in the inlet you should feel air going in and when you turn it upside down that air should stop .

Is the inlet valve seat removable ? Some carbs have a oring there it could be damaged

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i feel your frustration but have you considered a new carb?? win/win situation...if you’ve come this far w the bike, why stop short of a new carb?? its one of the best mods you can do the BRP

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3 hours ago, webmonstro said:

Either the inlet valve is worn or dirty or the float is stuck .


Did you replace the inlet valve ?
With the carb off the bike if you turn it upside down you must hear the float closing .
If you blow in the inlet you should feel air going in and when you turn it upside down that air should stop .

Is the inlet valve seat removable ? Some carbs have a oring there it could be damaged

I polished it after I found an old thread on here but the actual brass insert is not replaceable for these carbs. Its part of the carb body. I can blow on it and the air stops when the float pin is activated. But if i use 50psi on the compressor and plug the float pin hole with my finger, air escapes around the sides. But yea this is not a replaceable part. Again, it was leaking weeks ago but still started and was running fine. Now it wont even start

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45 minutes ago, timbanditos said:

Float is either adjusted wrong or worn out. If you replaced the float and still have the leaking fuel issue it it not adjusted correctly. Have you rebuilt a carb before? Setting the float is key for each carb and each setting is different for each carb.

Like i said before. I used the old float to experiment. leaks all the same at 25mm and 8mm and every interval in between. yes hundreds of times in my life

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2 hours ago, Sumoman said:

i feel your frustration but have you considered a new carb?? win/win situation...if you’ve come this far w the bike, why stop short of a new carb?? its one of the best mods you can do the BRP

IDK man, in hindsight, yea I should have dropped 800$ on the lectron carb. But I'm already 200$ into this one and now its a pragmatic issue with me. It was running fine before even though it was overflowing. But now it wont even start or burp. So i need to diagnose this or I will go crazy.

I know too many other people with the pumper carbs that have trouble adjusting. I ride all over the country and put it in my truck to take camping and ride trails in the rockies, canada, mexico so I need something that either doesnt need rejetting (the expensive lectron) or one that I can easily change the jets when at altitude or temp changes (which leaves me with the stock carb). Also, a pumper carb is no better (read powerful) than an uncorked and rejetted stock bike. Pumpers just eliminate the 0.3 second delay when blipping the throttle.

So basically at this point I have all the same parts that had it running 2 weeks ago. So id rather solve this puzzle

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24 minutes ago, hockeyrick said:

So why not break down and buy the best carb (LECTRON)  and be done with it??

HAHA well I would love to but its a thousand dollars. That same thousand dollars can be used to do a top and bottom end rebuild which I was eventually planning to do since I love these engines and wanted to do a full restoration on it. But Im also doing a full restoration on a 1972 BMW 2002tii so I need to start making tough choices. I also dont have that thousand right now and the bike hasnt run for 2 weeks so something needs to happen.

Just posted to craigslist to try and recoup some of my loss. Hopefully someone will offer 2k or 3k and I wont feel so bad.

I travel between panama city fl, NOLA, austin, and DFW. So I'm planning on listing it all those places until i get a hit

https://dallas.craigslist.org/ndf/mcy/d/grapevine-xr650r/6932996560.html

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Well its solved!

There is a screw at the bottom of the carb. Not the pilot! Apparently it closes the drain. IDK why but we turned it 810 degrees to where it all the way closed. I guess its a drain since it sits at the bpttom and isnt connected to anything else. Its not labeled in the manual. Backfired first kick and started right after that. Idle screw had been messed with in all this commotion so i had to get that settled as soon as it started.

It still doenst make sense, IDK why it was fine for months, because I never touched this screw, nor have i touched it on other xr650r ive been with.

This part is not labeled on any diagram (either in the manual or on partzilla) so if anyone knows what it is, id like to know.

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44 minutes ago, Arrowtree551 said:

Quiter!

Hahahah. I was already defeated when i made an account here and hearing people tell me to buy a new carb just made me bitter. It was working and ill be dammed if it wont be working again haha.

I appreciate everyone's help and hope my followup will assist anyone in the future (i learned after i got in tech field to always post the solution because there's nothing more annoying than searching stackoverflow only to find people solved it without posting how.

Now i have a BMW to finish. but i would still like to know if this is indeed a drain as well as why it would suddenly start giving me problems

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Most likely it was just dirty on the tip . Allowing some gas to escape. Then just that bit of dirt just dislodged it self .
All Moto carbs I've seen have a drain screw . There kind of obvious if you look at the float bowl from the inside you usually see the path to the screw . I had one carb that had to sand down the tip as it never seald correctly

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