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Old 06-23-2008, 03:44 PM   #1
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Default Why did my 2 of my OS Vspec carbs break like this in less than a lap?

Why did my 2 of my OS Vspec carbs break like this in less than a lap? I had my V-Spec in my ST-RR for over 8 race days now. I'd say almost 2 gallons thru the engine. I have changed NOTHING on my truggy except clutch shoes and bearings. With the ST-RR you don't need to worry about gear mesh once it is set due to the engine mount design so I know I didn't mess up the mesh.

OK, so I went to a race Saturday. I practiced 2 tanks Friday and all was fine. I went out Saturday morning and on my first lap I completed as I went down the straight my engine just stopped half way down the straight. I thought, crap I just threw a rod. I picked up the truck and tried to spin the fly wheel. All felt good. It took me a second but I then noticed fuel dripping from the chassis. So I thought the fuel line came off, but upon inspection I seen the rear end of the carb blown off. I was like WTF?

So I found someone who had a spare V-Spec carb. I threw it in and started it up. Engine sounded good and ran good on my box until it got up to temp. I put it on the track and less that 1/4 of the first lap the new carb blew the rear end off. Then I was really mad. I just pulled the engine and dropped in my backup, which was not as strong as this one, so I was sad the rest the day.

I have absolutely NO IDEA how the engine can cause this part of the carb to blow off. I don't feel like buying another $100 carb to blow apart on the first lap. What could cause this?

Has anyone seen this before? Any ideas at all? Would OS replace them or give a discount off another?

Thanks


(Sorry for the blurry pic, and yes I know the Mid-range needle is too far out, I pulled it to inspec for a cause)
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Old 06-23-2008, 05:24 PM   #2
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What happened to the thermo sleeve that's supposed to be on the base of your carb. ? I am going to guess and say It may have been hit while racing and cracked it then viberated to the point of breaking .I have had v-spec's for a very long time.Old style and the new . I have never seen this happen.My second guess would be You were trying to pull on the carb.to get it removed from the crack case (which the carb's on these motors do get stuck )hence why the thermo sleeve is missing. You may have been cracking on the high speed needle area to get it off and it got stressed and maybe cracked it . Just speculating( no pun intended) good luck ..
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Old 06-23-2008, 05:51 PM   #3
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wow never seen that before....
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Old 06-23-2008, 06:14 PM   #4
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I had that happen to me this weekend also, and seen it happen to 2 others.
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Old 06-23-2008, 06:55 PM   #5
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Actually that is the carb I got from the other guy. I had a very hard time removing that thermal sleeve from the first one that broke. I had to put a heat gun to it to remove that sleeve. Now the sleeve is stuck in the engine. So I can't say how that carb was removed, but I know for sure on the original one that I did not crank on the carb.

Regardless, how would it happen to 2 carbs in less than 1 lap? I would assume the engine has something to do with it?

I was told by another racer they had a friend who had this happen before as well.
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Old 06-23-2008, 07:05 PM   #6
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Sounds like a bad batch too me. I'm sure OS will take care of you. They warranty almost everything from what I hear.
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Old 06-23-2008, 07:16 PM   #7
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Unfortunately there is no warranty on the v-spec. However, It cant hurt to contact them and see if they can help you out. One question would also be if there was proper clearance between your carb and center diff? On my 8ight I have to angle the carb a little to account for chassis flex. If I didnt angle it I could see something like that being a possible demise of my v-spec as well.
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Old 06-23-2008, 07:28 PM   #8
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thats definetly a first for me..
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Old 06-24-2008, 02:04 AM   #9
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Yes a common faul tof the V spec among others. I have been told about this and is caused by changing the angle of the fuel nipple. So i have been told.

The new V Spec has a re issue carby and block as I bought one.
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Old 06-24-2008, 06:20 AM   #10
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Well I definitely changed the nipple position, that sucks if this is the cause.

Can I use a LRP 28 carb in this V-Spec? I happen to have 1 laying around.
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Old 06-24-2008, 08:34 AM   #11
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The 2007 and earlier Vspec carbs are a press fit for that part. It's rare but a few people have had it to pop out. If the high speed needle or fuel nipple is sticking way out and you land upside down on it, that could maybe have forced it to pop out.

The 2008 Vspecs have a new carb that is no longer press fit and that problem has been eliminated.
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Old 06-24-2008, 05:56 PM   #12
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That sucks that happened to you, when i have seen this before it was from trying to pry out your carb from the crankcase. if you tighten your carb neck too tight, it will damage your thermo sleeve and it can cause it to get stuck in your crankcase...i know another individual who did this and snapped it off trying to pry it out...you have to remove your needles and o-rings, boot, bake it in the oven then remove your thermo sleeve so you wont break your carb.

i have yet to see one break in a crash...and i have been in some horrid crashes lol but i guess there is a first for everything.
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Old 06-24-2008, 08:59 PM   #13
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I didn't crash, land upside down, land funny, nothing like that.

I never even had removed my original carb that was in there. First time I removed it was to replace it.

I was simply driving down the straight at WOT when the first one blew. Then I replaced it and not even 1/4 lap in the second one blew.

Last edited by LosiSuperTruck; 06-24-2008 at 09:36 PM.
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Old 06-24-2008, 09:37 PM   #14
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So we all agree that the engine had nothing to do with blowing the carbs? I can't think how it could, but I would like to know your opinion even before I waste the time to try my LRP Spec3 carb on it.

Thanks
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Old 06-24-2008, 11:15 PM   #15
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I personally do not see how your engine would make your carb fall apart..

OS Carbs are probably the easiest to maintain and are pretty durable i might add...i think the only other carb that could be better in comparison to is a Novarossi.

at any rate, when you install your new carb, make sure you do not over tighten your carb neck. it will pinch the thermo sleeve and will be a nightmare when you attempt to remove your carb from the crankcase.

good luck at getting your engine back together. its a learning process for us all. i personally would just buy a new carb off of EBAY or an online hobby shop. good luck.

Jesse
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