FLAW IN CASTING OF CARB

[rowdy13]

Just to update everyone, I've been griping for a long time about my bike coughing all the time. I dont do much highway driving, but two weeks ago I took it out on the highway, and in 4th gear at approximately 3000 rpm's , my bike would start coughing, repeatedly. I took it in again, and I got the "bikocondriak" look from them, but the tech took it out on the highway. when he got back, he said he did witness the coughing. I felt like someone else had seen the same UFO I did. Anyway, its been in the shop for a few days, and they just called and said they replaced my carb. They said they found a "flaw" in the carb, that was put there when they made it. They said during the "casting' of the carb, there were a few flaws. They said mine is the second one they have found. SO, you guys who have the same problems I've been having, you might have them check for the "flaw". I have no idea what the flaw is, or what to look for, but if anyone is interested, let me know and I'll find out. I havent test driven it yet, will do that tomorrow and will give a report. Just wanted to let you guys know, that take your bikes in all the time because of coughing and the tech says there's nothing wrong with your bike, about this info. dont know if its already been reported on this site, but if this is a repeat, I apologize. Peace, Rowdy

 

[Oscar Maldonado]

Thanks for the heads up Rowdy. This is the first that I hear of this.

 

[rowdy13]

they said something to the effect that it would be covered under a recall. so it didnt cost me anything. my question, is if there was a bad "cast", wouldnt there be a lot of them with "flaws"?

 

[Tim]

Thanks for sharing the info rowdy!

I would think there would be more reports of carb problems, but I guess it all depends on what the flaw is and if it was only a handful of carbs or not.

 

[KnotSo]

Take it out on the hwy and run it up opver 80mph so you can experience 6th gear! This is where the fun zone kicks in.

I would bet that several had carb issues and just went straight to the XXX carb or pSI, or similar.

Let us know how your new carb works and please post more details and pics if possible of theis "flaw"

Thanks

 

[lee]

I suspect a lot of people with similar issues, as long as they don't actually stop you riding, accept them

 

[rowdy13]

I picked up the K-9 today and it ran like a scalded dog. Didnt get to take it on the highway yet, but it ran great on the side streets to get home. They showed me the flawed carb they took off my bike, and showed me the inside of it. Its something I would never have noticed, but there were some rough areas in the carb. I ran my finger over them and compared to the rest of the carb, it was rough. Big Dog wanted them to send my old carb into them, and they said this may be the answer to several other problems they cant seem to solve. I'm going to try and explain what the problem was, but understand that I do not know carb terminlolgy, so I will use words like "thing" a lot. anywho, here's my explanation of what was wrong. When you take the air breather off, and you look at the carb part that looks like the end of a trumpet, and the area where the gas squirts when you accelerate, it should be very smooth inside that carb. Mine had some very fine rough areas in it. They said that the problem "May" have been when they are pouring into the cast, the metal, or whatever it is, must be very hot. they said mine "might" have been poured when they turned the machine off, and the metal wasnt as hot as it should have been. That was just a shot in the dark explanation, so dont know if that's the real problem or not. anyway, there's probably a lot of you out there that have the same problem I had, and your tech cant figure it out. hope this helps.

 

[Oscar Maldonado]

Good deal Rowdy!

 

[rowdy13]

I just took my K-9 out on the Highway and all I have to say is Holy Shit! My bike today ran BETTER than when I bought it. No coughing, no cut out, unbelievable throttle response, etc... I have nothing bad to say. I kinda feel like to guy who found the cure for a dreaded African virus, or should I say found the doctor who found the cure! I will try to found out more details on the carb flaw problem, and let everyone know. Hopefully I will be able to explain it in mechanical terms, instead of "thingy". If anyone knows the mechanical terms to what I'm trying to say, by all means help me out. I would try to take pictures of the flaw in the carb, but I dont think my camera would pick up the problem. Its not a very sophisticated camera, nor is the camera user. Right now I need to drain my "thingy". More later

 

[Gas Man]

Glad you got it fixed... oh and XXX'in the carb would have fixed that too!

Chopper Dave just had his carb replaced too. Don't remember what his issue was.

 

[Chopper Dave]

Glad you got it fixed... oh and XXX'in the carb would have fixed that too!

Chopper Dave just had his carb replaced too. Don't remember what his issue was.

actually they rebuilt my carb....Big Dog was going to send send FT a new carb....but that was on order .....so Doc said he rebuilt my carb....runs great!!

 

[alhall88]

If you still have that old carb look to see what the mold number is, should be a boss with some raised letters and or numbers. That way if other forum members have any issues they can reference that number. Sometimes it just a problem with that cast and sometimes there's an issue with that tool and all carbs that were ran with that tool will have the same issue until the mfg. corrects it. If that was a problem there should have been a containment at the foundry.

 

[Cutter]

Glad you got it fixed Rowdy :up:, too bad you had the problem in the first place.

If you still have that old carb look to see what the mold number is... Sometimes it just a problem with that cast and sometimes there's an issue with that tool and all carbs that were ran with that tool will have the same issue until the mfg. corrects it. If that was a problem there should have been a containment at the foundry.

Good call Al, hopefully it was just contamination in Rowdies carb...

 

[RRRUFF]

Thanks for the info Rowdy! :up: No issues with mine however but good to know.

 

[Gas Man]

If you still have that old carb look to see what the mold number is, should be a boss with some raised letters and or numbers. That way if other forum members have any issues they can reference that number. Sometimes it just a problem with that cast and sometimes there's an issue with that tool and all carbs that were ran with that tool will have the same issue until the mfg. corrects it. If that was a problem there should have been a containment at the foundry.

Sounds like a man with expierence!

 

[P8RIOT]

...Right now I need to drain my "thingy".

Ummm - thanks for not getting too technical on that issue, Rowdy!

Sounds like what you are saying is the surface area of the venturi was rough. As an aeronautical engineer, I can tell you that would raise hell with smooth fluid flow in a critical area, but I don't know that it would necessarily cause all the symptoms you were describing.

Regardless, it appears the problem is gone, and that's the bottom line. :up:

 

[rowdy13]

P8RIOT, thank you for translating my non technical terms into technical terms. I have no idea if the rough area of the carb had anything to do with the coughing, spitting, sputtering etc..., but with the new carb, everything is 100%. On start up, my bike would cough and die, cough and die. That is 100% gone. When I would accelerate, there would be a slight hesitation, that is 100% gone. When going through a turn, my bike would cough. That is gone. At 3000 rpm's going about 65 to 70 in fourth gear, I had horrible coughing over and over again. That problem is gone. I'm going to find out if they did anything else other than replace the carb, and let everyone know. I'm just so relieved that they found the problem, and repaired it. It was getting to the point that I hated going for a bike ride.