Edelbrock Carb problems again


126 replies to this topic
  • SoCalDirtDevil

Posted February 18, 2006 - 03:26 PM


Well I dusted off the 650 and when she didn't start I changed out the gas several months old. Still nothing. Went and got a brand new plug. Still nothing. Figured I clean out the carb with some cleaner and that should do it. Well lo and behold I discover no fuel is getting to float bowl. Couldn't figure out why the valve was stuck so sprayed it with carb cleaner and came in here to search for this problem and lo and behold I find a year old thread on the subject. Thanks to all who posted information here. After some reading and a view of the most excellent photos I went back to the garage to tackle the problem. Lucky for me the carb cleaner loosened the valve and I was immediately back in business. Bike back together the old pig started with two kicks wooooohoooooooo!!!!

  • creeky

Posted February 18, 2006 - 04:19 PM


Just discovered this thread, great stuff. I too had the "problem" with the EB on my '96 XR628 (sold it, still kicking myself in the a**). After I discovered what was causing the "problem", I started draining the float bowl when I parked the bike and removing the fuel hose and squirting a little carb cleaner in and replacing the hose. This worked with no more "problems" for 2 years until I sold the bike. Apparently the carb cleaner dissolved the gum (if any) and the valve didn't stick. Also I have adopted a practice of draining the fuel into the lawn mower can if the fuel is more than two weeks old and using fresh. No proof that this is helping, but as said, no more "problems".

  • adam574

Posted May 19, 2006 - 01:36 PM


keep bringing this old thead back... had a question on this. when you guys say the fuel valve sticks is it only from sitting or does this happen during riding. also does anyone know if edelbrock has solved the problem yet

  • qadsan

Posted May 19, 2006 - 01:48 PM


It can happen for a number of reasons. Stale fuel or poor quality fuels that varnish, or form gum / resin can cause the valve to stick. It can also be a problem with the part itself or dirt / particulate causing the problem. I don't know if Edelbrock has recognized this as a problem or not, but they have played around with different designs of this valve for whatever reason. Maybe they wanted to improve it or perhaps they're using a different suppliers, etc. Call them up and ask them if you want the facts from them.

If the valve sticks closed, the bike can be hard or even impossible to start. If it sticks while riding, the symptom will be as if you're running out of gas.

So far so good for me since I bought my first Edelbrock in late 2001 and I've bought several more since, none of which have had this issue.

  • creeky

Posted May 19, 2006 - 04:50 PM


Sticking float valve, caused by a problem I haven't seen before. Last week my Edelbrock equipped WR400 started running lean off and on, especially when I was WFO for 30 seconds or so, so my first thought was that the float was hanging up or maybe there was crud in the tank strainer or somewhere causing poor fuel flow. Took the float bowl off and lo and behold, the little springy thingy that clips on the float valve and goes around the tang on the float was broken. I connected the fuel line to the bowl (bowl off carb) and the gas flowed in very slowly until I would nudge the valve a bit, then the bowl would fill. If I pushed the float down, gas would flow in only very slowly, sometimes not at all. Apparently the springy thingy has to be on there so that the float will pull the valve open when the float drops. You guys probably all know about this, but in 25 years of dirt biking, I have just now come to the realization of just what the spring is for. Go ahead, Iv'e been called stupid by experts. Called Edelbrock, they are sending me a new float valve assy, no charge, I call that stepping up to the plate.

  • Old_Man_Time

Posted May 19, 2006 - 05:20 PM


Sticking float valve, caused by a problem I haven't seen before. Last week my Edelbrock equipped WR400 started running lean off and on, especially when I was WFO for 30 seconds or so, so my first thought was that the float was hanging up or maybe there was crud in the tank strainer or somewhere causing poor fuel flow. Took the float bowl off and lo and behold, the little springy thingy that clips on the float valve and goes around the tang on the float was broken. I connected the fuel line to the bowl (bowl off carb) and the gas flowed in very slowly until I would nudge the valve a bit, then the bowl would fill. If I pushed the float down, gas would flow in only very slowly, sometimes not at all. Apparently the springy thingy has to be on there so that the float will pull the valve open when the float drops. You guys probably all know about this, but in 25 years of dirt biking, I have just now come to the realization of just what the spring is for. Go ahead, Iv'e been called stupid by experts. Called Edelbrock, they are sending me a new float valve assy, no charge, I call that stepping up to the plate.


On the XR650R's Edelbrock carb there is no spring that connects the valve to the float. Did your carb actually have a spring or did you assume it must be missing? If yours has a spring it is a slightly different design than ours. Everything is operated off of fuel pressure for both shut off and opening of the valve. If you are having the same problem polish the bearing surfaces of the new valve with 6000 or 5000 grit before assembling the unit. After all this time mine still works great. I thought it might be sticking when the bike sat for a long period of time so I repolished the valve the other day and even when the bike sits it starts right up again.

  • creeky

Posted May 19, 2006 - 05:59 PM


On the XR650R's Edelbrock carb there is no spring that connects the valve to the float. Did your carb actually have a spring or did you assume it must be missing? .


The Edelbrock on my WR400 is an older model with the enrichment valve for cold starting and no accel pump. The "spring" that I am talking about is actually a clip that snaps over a groove on the valve and wraps around the tang on the float that pushes against the valve. Half the clip was still on the valve, the other half in the bottom of the bowl. The parts list that came with the carb shows the clip, but as part of the complete valve and seat assembly. I took apart an old XR400 stock carb that was laying around to see if the clip from that would work, but it was too small and would not fit. The gentleman that I spoke with at Edelbrock told me that the clip has been a problem in some cases and is sending me a freebie.

  • BWB63

Posted May 19, 2006 - 07:27 PM


I have had this broblem on both my Edelbrocks....Like I said before, it seem to happen when I trailer the bikes with fuel in the float bowl. If I run it dry before I trailer it it doesn't happen as much and if it does I do not have to hit the carb as hard to knock it loose.

Posted Image


http://xr650r.borynack.com/

  • 4Takt

Posted May 20, 2006 - 07:15 AM


SNAKE OIL ALERT:

A local company here makes a fuel conditioner that I use occassionally. I got hooked on it after restoring an old BMW Airhead. It had been sitting for years and the carbs were so gummed up and full of varnish they looked like solid rust inside. After running two tanks with a few ounces of this conditioner the carbs looked brand new. I now put an ounce or so in every third tank of all my bikes. Carbs look like fresh off the production line every time I open them. This stuff also removes all the acid and water, so I don't get any corrosion at the bottom of the float bowls. Raises octane and cetane as well.

I haven't had any issues with my Edelbrock's float valve sticking.

Check out the link, the stuff I use is the Excelube Marine

http://www.batonroug...om/products.htm


4Takt

  • pbusanga

Posted May 22, 2006 - 03:58 AM


hi if the float tab were to be 'hooked' to the back of the the float needle as the float drops (no fuel) it would pull the needle open thus not just relying on fuel pressure alone but weight of float bladder itself to activate float needle. i remember some old carbs i used to work on had a groove which hooked onto the float tab. perhaps this is what edelbrock should do. ...my 2cents

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  • Old_Man_Time

Posted May 22, 2006 - 06:25 AM


hi if the float tab were to be 'hooked' to the back of the the float needle as the float drops (no fuel) it would pull the needle open thus not just relying on fuel pressure alone but weight of float bladder itself to activate float needle. i remember some old carbs i used to work on had a groove which hooked onto the float tab. perhaps this is what edelbrock should do. ...my 2cents


The Edelbrock valve is positioned horizontally in the carb rather than the traditional vertical valve. When I talked to Edelbrock they said they had more problems created trying to attach a float wire to the valve. The fuel pressure open and close they have works fine as long as the bearing surfaces are polished to a high sheen.

  • adam574

Posted May 22, 2006 - 09:17 AM


call me totally stupid but couldn't you tap the bowl a couple times with a rubber mallet and maybe the thing would unstick

  • desmo900

Posted May 22, 2006 - 04:47 PM


The Edelbrock valve is positioned horizontally in the carb rather than the traditional vertical valve. When I talked to Edelbrock they said they had more problems created trying to attach a float wire to the valve. The fuel pressure open and close they have works fine as long as the bearing surfaces are polished to a high sheen.


I just received a new float valve last month form Edlebrock, and the needle came with a wire clip that attaches to the floats. I wonder why they are shipping it with the clip if its not working right. Mine seems to be fine. I rode 60 miles of shudder bump fire road on Saturday with no issues.

  • August

Posted May 22, 2006 - 06:14 PM


I am logging on here for the first time in over 6 months. I parked my 650R last august after fitting a new Edlebrock and the bike would barely run. I have been busy with my track bikes and roadracing.

I pulled it out today and went over a bunch of maintence stuff and other things.

Try and fire it up, its a bitch, finally get it going and it runs like crap...or barely runs I should say, I want to throw this thing in the garbage!!

WHAT THE F$&K is wrong with this thing!!!!

I didnt install it, I had a guy who really knows his way around mx bikes do it when he freshend up the suspension last may. I have tried every setting and THIS THING WILL NOT RUN RIGHT!!!! &%$#@!!!!!

I can jet and tune a Honda 250 GP bike and I CAN NOT DO THIS!!!! :ride: :banana:

The bike finally starts idles very eratically and when I give it gas it will not come back to idle...or if it does , its very slow...is it an air leak?? It pops and farts, it seems rich yet seems lean and like it has an air leak...I will admit I have sdjusted everything short of pulling it all the way back off the bike which I will do tonight....

Any tips before I smash this thing with a hammer and go back to stock?
I just got a plate on this bike, I want to ride it :busted:

Please help!

  • adam574

Posted May 22, 2006 - 08:06 PM


check the float level. i am pretty sure somewhere in these 18 pages someone said that solved there problem on what seems to be the same one you are having.

  • 4Takt

Posted May 22, 2006 - 08:44 PM


The bike finally starts idles very eratically and when I give it gas it will not come back to idle...or if it does , its very slow...is it an air leak?? It pops and farts, it seems rich yet seems lean and like it has an air leak...

Please help!



Mine does the same things. It's very inconsistent, some days it runs like a champ, some days it idles like crap, surges and coughs. Float level seems fine.

  • RingKingPin

Posted May 24, 2006 - 02:46 PM


Dear ThumperTalkers,

My xr650r has 15,000 miles on it. I ride in talc quarries and sand. The last time I rode the bike, I ran the tank dry and put it away. That was 8 months ago. The bike doesn't want to run properly, what is the problem? :ride: :busted: :banana: DUH!

LOL, just kidding but seriously, these are the things to check.

1) Clean the carb! Chances are that there is a ton of crap in there. Also, pull the pump and clean that journal, be careful not to lose the BB that sits down there. Also, inspect the rubber pump membrane, they wear down, especially if there is sand and dirt down there.

2) Make sure that the valve that is actuated by the float is moving freely. Remove the float and do a visual inspection. Also see if you can get it to catch up on itself. This has been a known problem. A little emory cloth or something similar can smooth the sides and keep it from happening. This is typical with a sandy carb

3) check and make sure ALL the drain and air lines are obstruction free. After battling with the first to points personally, it took me a long time to see that the air tube had been melted shut from hitting something.

4) Finally check the linkage and make sure it moves in BOTH directions freely.

5) Run it like a mofo and take a plug reading to make sure it's not too lean---that can lead to erratic idle and hard starting

6) CHECK YOUR VALVES! It might not be a carburation problem at all.

I'd bet about anything it's one of these problems.

G'luck.

Geoff

  • August

Posted May 25, 2006 - 09:10 AM


Thanks for the tips geoff, but my problems were with a brand new carb out of the box. I did pull everything apart except the pump, there may have been some small burrs on the float needle making it stick, everything was very clean, but I cleaned it all with contact cleaner to be sure, bowl fills up a bit faster but still about 6-8 seconds. I am going richer and it is starting to run and idle now...valve adjustment was checked 3 times...spot on. I am thinking it may have been a combo of sticking float valve and lean condition combined...still gotta play with it some more...thanks everyone for the advice!

  • HC

Posted May 25, 2006 - 09:08 PM


mike, wouldnt a e-start be worth it? extra 15 lbs, ?

  • ztsd

Posted May 31, 2006 - 06:41 PM


I have had this broblem on both my Edelbrocks....Like I said before, it seem to happen when I trailer the bikes with fuel in the float bowl. If I run it dry before I trailer it it doesn't happen as much and if it does I do not have to hit the carb as hard to knock it loose.

Posted Image


http://xr650r.borynack.com/

Just experienced this last week. Took the bike out to the Dualsport ride in Western Mass, about 2-hour ride in the trailer each way. Ran fine on the run. Went to start it up a few days later and the valve stuck. Total of less than 150 miles on the new carb. After that, I’m running the bowl empty when I’m done riding for the day.

I also thought that the problem might be aggravated by close proximity to the header. I figure the QC is fine when running as the flowing fuel would tend to keep it cool but when it was shut down, the heat from the header would boil off the fuel and varnish the needle. On my bike the brass screw was almost touching the header.

So, I tweaked the subframe back inline which gave me a quarter inch and then I used a piece of fuel line under the rear of the gas tank to lift it a bit so I could straighten the QC and get more space and it looks much better now.

I’ve been thinking about this since and I’m gonna try making a heat shield for the carburetor. I’ll start with a Dunkin Donut cup of the appropriate size and see what happens. Couldn’t hurt keeping the carburetor a little cooler anyway...
:applause:





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