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CRF50 carb frustrations

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I bought a an '06 dirt cheap knowing it didn't run well, but I figured I could blow some carb cleaner through the carb and all would be well.

Unfortunately, it hasn't turned out to be that easy.

 

Known issues:

  • To keep it running, I had to turn the idle up a little higher than normal, which causes the throttle to hang after closing the throttle. If I back the idle to "normal" it just won't stay running. I know that is indicative of a pilot jet clog, but from what I can tell, you can't remove the pilot on this thing. 

 

  • The petcock won't completely shut the gas off. I figured a $10 gasket kit would fix that, so I wasn't worried about it when buying it, but it appears from Honda's schematics that the petcock cannot be repaired, and a replacement is $50. That isn't a huge issue, as I know tons of people leave their gas on all the time (My KLX doesn't even have an off position). However, gas leaks out of the overflow tube sometime. It is kind of random, but sometimes I will walk into the garage and I can see a little spot on the concrete where she puked some gas. Does this mean I have some sort of float issue?

 

 

  • The throttle must be rolled on slowly after 1/4" throttle. I know many people fight off-idle bog on their bikes, but my problem is different. I can crack the throttle fast from idle up to 1/4" turn and it responds fine, but past that, the throttle has to be applied slowly or it bogs until it finally shuts off. It runs fine at any throttle position...it just can't be rolled on quickly.

Any thoughts? I have sprayed multiple cans of carb cleaner through every orifice/port/opening/hole/jet/whatever that I can see. I have blown bookoodles of compressed air through it also. All to no avail. I appreciate any advice yall have :ride:

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The pilot on these carbs is a factory set, non-removeable jet that is very hard to clean.  There are many threads on those who have tried to remove, but there are also many stories of those who failed (I am one of them).  The best bet is to replace the carb with either OEM or aftermarket.  

 

I think you should check the valve lash on the engine.  Not saying that is the issue, but you want to make sure they are set correctly before messing with other things.  As for the petcock, check ebay for a replacement.  Yes, Chinese made, but it beats $50 for a cheap 50.

 

Let us know how it goes.

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The pilot on these carbs is a factory set, non-removeable jet that is very hard to clean.  There are many threads on those who have tried to remove, but there are also many stories of those who failed (I am one of them).  The best bet is to replace the carb with either OEM or aftermarket.  

 

I think you should check the valve lash on the engine.  Not saying that is the issue, but you want to make sure they are set correctly before messing with other things.  As for the petcock, check ebay for a replacement.  Yes, Chinese made, but it beats $50 for a cheap 50.

 

Let us know how it goes.

 

Thanks for the advice!

 

Which is the best aftermarket carb out there? OEM carbs aren't too expensive at $90, but if a good aftermarket can be had for less, then I believe I'll go that route.

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Thanks for the advice!

 

Which is the best aftermarket carb out there? OEM carbs aren't too expensive at $90, but if a good aftermarket can be had for less, then I believe I'll go that route.

I have a 19mm Mikuni, but that engine has also been upgraded with a big bore kit.  If you are keeping it stock, then go with the stock carb.  The chinese carbs do fine, but fitting them can be the issue as you will need a different throttle cable.  

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I went through this exact same thing a couple of weeks ago. I bought an 06 that Crunk first kick. Brought it home and Crunk first kick but when I throttled up it would not idle down for several seconds. Ordered a new throttle cable since the old one kinked. Same thing, so I cleaned the carb as best as I could due to the pilot jet being non removable. Same thing when I fired it up. I had a motor in a box from an 04, so I installed the old carb without cleaning it or taking it apart and it Crunk first kick and has ran great. Guess we didn't use ethanol in 04! Buy a carb, that's the only thing I knew to do

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Sort of a thread jack, but i just bought an 05 today for my son and it has the same issues. Partzilla has a carb assembly for $78, $72, and $68 for an A, B, and C respectively. Not sure what the differences are but its a pretty decent price. Im interested to hear what you did to fix this

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I was having the same issues with my sons xr50. Fuel filter disintegrated and clogged the pilot. Would run very well for about 30 minutes the just die ( after thoroughly cleaning the carb). Tried everything. Just ordered new carb pet clock and fuel line. Hope that takes care of it!!!!!

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I was having the same issues with my sons xr50. Fuel filter disintegrated and clogged the pilot. Would run very well for about 30 minutes the just die ( after thoroughly cleaning the carb). Tried everything. Just ordered new carb pet clock and fuel line. Hope that takes care of it!!!!!

 

Have you tried the new parts yet?

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Yes! Installed everything and fired it up first kick. Idles so well and runs so much better!!!! Definitely worth it

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What did you end up going with? New stock carb?

I just ordered this from Amazon...I went Amazon since I have prime and this looks identical to stock, even though I know it isn't...

PCC Motor, Stock carb for Honda...Got good reviews.

 

BTW -I purchased this bike from my brother, and he tells me that the bike has never seemed to run well and he has always suspected the carb. (even when new). 

I am hoping for a carb that just runs well on the stock bike. (should I run pod filter, or will that make it run poorly?)

PCC Motor -Carburetor Honda Crf50 Crf 2004 - 2009 Stock Carb Ca28

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Had same issues.... until I went to Pep Boys bought a gallon can of cleaner with dip basket.....removed carb and stripped down so the float and other parts were off.  Placed in can overnight......Bam....bike runs like the first day I bought it.  The gas these days gums up very quickly if you let the bike sit for any period of time.  Thought this may help some.

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What did you end up going with? New stock carb?

I just ordered this from Amazon...I went Amazon since I have prime and this looks identical to stock, even though I know it isn't...

PCC Motor, Stock carb for Honda...Got good reviews.

 

BTW -I purchased this bike from my brother, and he tells me that the bike has never seemed to run well and he has always suspected the carb. (even when new). 

I am hoping for a carb that just runs well on the stock bike. (should I run pod filter, or will that make it run poorly?)

PCC Motor -Carburetor Honda Crf50 Crf 2004 - 2009 Stock Carb Ca28

 

 

I never solved the problem 100%. My older boy prefers his KTM Mini Adventure, so until my little one gets olds enough to ride the Honda, I'm not going to worry about it. I did make it run a little better by soaking the carb overnight like LAPII suggested. After doing the soak, it would run in the middle choke position just fine. Still, that isn't the way it should be. Currently, the bike is drained of fluids and waiting for my little one's 4th birthday. 

 

When the time comes, it's getting a new OEM carb.

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Update.

I could not get the pilot unclogged. I tried every trick I knew. Finally just drilled it out, and the bike ran -but it was running for crap.

That carb I got from Amazon, the PCC unit that looks just like the stocker, is in the bike. I used the old throttle cable, slide and needle (came out as a unit) dropped it in the new carb after pulling the cap, spring and slide out, and second kick the bike was running. Let it warm up a bit, and I am betting that the bike never ran this good, even new. So now this bike is running, and I just picked up a Kuberg Start today -which will be for my son's 3rd birthday a few days before Christmas. I am really liking that bike -but that is another topic...

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Update.

I could not get the pilot unclogged. I tried every trick I knew. Finally just drilled it out, and the bike ran -but it was running for crap.

That carb I got from Amazon, the PCC unit that looks just like the stocker, is in the bike. I used the old throttle cable, slide and needle (came out as a unit) dropped it in the new carb after pulling the cap, spring and slide out, and second kick the bike was running. Let it warm up a bit, and I am betting that the bike never ran this good, even new. So now this bike is running, and I just picked up a Kuberg Start today -which will be for my son's 3rd birthday a few days before Christmas. I am really liking that bike -but that is another topic...

 

This one?

http://www.amazon.com/Motor-Carburetor-Crf50-Xr50-CA02L/dp/B007PJ9ZWI/ref=sr_1_2?ie=UTF8&qid=1416769943&sr=8-2&keywords=xr50+carburetor+pcc 

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TECH:

 

RUNNING CONDITION

Please got thru these steps:

Engine and Carb quick check list:
http://tboltusa.com/store/tech.php?pID=88/Engine+and+Carb+quick+check+list

To Check Valve lash (Tappet adjustment):
http://tboltusa.com/store/tech.php?pID=62/Top+End%2C+Valve+Clearance%2C+and+Timing

Jetting guide:
http://tboltusa.com/store/tech.php?pID=61/Simple+Guide+to+Jetting

Most of the time you can tune bikes in with the needle and brass screw adjustments and not need to change jets 
 

Edited by T Bolt USA
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I was having the same issues with my sons xr50. Fuel filter disintegrated and clogged the pilot. Would run very well for about 30 minutes the just die ( after thoroughly cleaning the carb). Tried everything. Just ordered new carb pet clock and fuel line. Hope that takes care of it!!!!!

What's a fuel filter?

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Take the petcock out of the fuel tank- chances are you will find what is left of the cylindrical cage that the screen/ filter used to house. Entire petcock needs replaced due to design. Hope this helps!

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