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Old 07-01-2008, 07:23 AM   #1
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Default How do I stop vapor locking?

I have a werks B3 that has all most 2 gallons on it. After about 4 minutes of driveing on the track the car will die and cannot be restarted untill it cools. Then it fires right back up. Im thinking it vapor lockign becuse I can hear the fuel bubling when I prime it to restart it. I check the temps right as it stalled and I was getting 230 - 245 range. It runs great when running, just wont go more that a few minutes. Is there any way to stop this other than richening it ? The performance really goes down when I richen it more that it is.
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Old 07-01-2008, 07:45 AM   #2
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If you have an aluminum carb without any kind of insulator, it will vapor lock when its hot. The easiest thing to do is use a can of compressed air to cool it down. Otherwise, get a carb with an insulator.
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Old 07-01-2008, 08:12 AM   #3
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have you temped the side of the case, you could be lean on the bottom end, and actually be temping hotter on the side of the case, rather than temping the head. fatten the bottom end needle a bit, and adjust your idle with the idle screw, so the gap is about 1mm. you should not vapor lock unless your running hotter than 300
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Old 07-01-2008, 11:38 AM   #4
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Good point xlgraphicspro, I didnt even think of that. I'll try checking that temp too.

I do have an plastic insulator around the carb, but the carb is aluminum.
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Old 07-01-2008, 04:30 PM   #5
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Quote:
Originally Posted by xlgraphicspro View Post
have you temped the side of the case, you could be lean on the bottom end, and actually be temping hotter on the side of the case, rather than temping the head. fatten the bottom end needle a bit, and adjust your idle with the idle screw, so the gap is about 1mm. you should not vapor lock unless your running hotter than 300
Vapor lock starts in the low 200's. Pretty much any alu carb will vapor lock once its up to temp.
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Old 07-01-2008, 11:04 PM   #6
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I have a B3 that I do have some trouble keeping the low end from going soft after about 4-5 minutes of running. I have to run the low end pretty rich but it will keep its punch through a 20 minute race. The only problem is that it takes about 3-4 minutes to warm up fully which is a bit more warmup time than I get. I have about 6+ gallons through the engine and it has never flamed out or given me tuning troubles. You just need to make sure the low end doesn't get too lean.
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Old 07-01-2008, 11:42 PM   #7
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Default Need Advise.

I own a used B3 partner with HN 053 pipe and love it too. Need advise on may I know average the B3 can run how long for one tank for buggy? I have run this engine for 4 weekend and today I found the LSN having oil leak, I can see oil all over the LSN screw do I set it too rich on the LSN? Or the o-ring need to check or change? Please advise. Thanks.
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Old 07-02-2008, 02:01 AM   #8
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You could buy a Trinity Extech!

They never vapor lock!

http://www.amainhobbies.com/product_...ducts_id/25377
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Old 07-02-2008, 07:23 AM   #9
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I'll try to richen up the bottom a little and see if that helps. Im also going to switch fuels as my current fuel (traxxas 33%) is pretty high in oil. I read some where else that this can be bad also.

Thanks for all the suggestions, I'll let you know how it goes!
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Old 07-02-2008, 07:39 AM   #10
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Quote:
Originally Posted by gubbs3 View Post
I have a B3 that I do have some trouble keeping the low end from going soft after about 4-5 minutes of running. I have to run the low end pretty rich but it will keep its punch through a 20 minute race. The only problem is that it takes about 3-4 minutes to warm up fully which is a bit more warmup time than I get. I have about 6+ gallons through the engine and it has never flamed out or given me tuning troubles. You just need to make sure the low end doesn't get too lean.

This post touches on the important thing to know about the Werks engines. They are notoriously "cold blooded" and take a good while to warm up. I you start one cold and the throttle is at all crisp or the engine already feels fast than you are likely too lean. These take a little while to get up to temp and can cause you to chase the tune around. I've been running my B7 with a JP2 pipe and that seems to lessen the effect (not to mention running pretty well) compared to the OS 2050 I ran before. It got better mileage with the 2050 though.
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