Fuel Vent

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rampagemt said:
It will run soo much better once tank is vented
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Especially with a mod 30.5, or adding a pipe. Fuel flow gets increased. Once I added 8" pipes to the X-Can on the stock 30.5 I couldn't keep it running till I put a vent kit on. Full throttle and 2 seconds later, silence.
 
Re: Fuel Vent

Does the tank need to get more air in or out? Just wondering if a one way valve in the cap would work
 
Both.

The engine gets starved of fuel if air can't get in.

If the fuel expands due to temperature increase while the vehicle is not being used, the pressure forces fuel into the engine causing flooding.
 
Lol, rcdad beat me to it. Vapor lock is suction. It needs to draw air in. Kinda like what happens to a Capri sun pouch. As you drink, the pouch contracts from the suction bc there is no vent.
 
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Yup got word from redcat,said they have seen that problem before with the crank bearings going right away and are sending me a new motor :) .also I'm putting an order in to ddm for dom pipe,tgn filer pre filter and v stack and also 7500 rpm spring question is should I wait to break the motor in before I install spring pipe and filter?
 
I'm curious about this too. I've always broke in atv engines, car & truck engines one way, I break it in the way it's gonna be driven. I've never ever had an issue. So what makes these 2 strokes so different? These are just weed eater motors. There was no break in procedure in any manual. The fuel mix is 25:1. No difference there either.
 
Re: Fuel Vent

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Heres how I did mine. I also took that little disc plug thing out of the cap to help vent better. No wonder they clog so easily just by looking at the cap innards

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Chief409 said:
I put in a vent kit from Snappy RC. You can't use the gasket in the kit for the fuel cap, the RedCat has a much smaller diameter filler. However the 3 hole grommet for the lines fits in the tank just fine. All you need to do is plug the vent hole in the gas cap, I used a toothpick, hasn't worked loose yet. Better yet, drill out the vent hole in the plastic filler cap and use a grub screw.
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+1 on that! thats what i did.. I was in Antelope Acres a few months ago picking up my dad.. wish id had the time to look ya up...
 
So here's my question, my buddy just installed his tank vent (bought the Snappy 3 hole grommet kit from DDM) and ran the vent line 1/2 " into the gas tank. Wen the engine is running gas starts making its way up the tube eventually out the check valve pouring fuel everywhere and flooding the carb. Anyone had this problem? We've tried mounting the valve facing up & down. This is with the cap sealed also. When we run a vented cap, the fuel never rise up the vent tube. How strange is that?
 
You gotta make sure the end of vent line is not submerged in the fuel.

How does it flood the carb? I can see it making a big mess. Is it dripping onto the air filter?
 
RCDAD said:
You gotta make sure the end of vent line is not submerged in the fuel.How does it flood the carb? I can see it making a big mess. Is it dripping onto the air filter?
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(I meant the engine flooded not the carb sorry) No gas made it to the air filter.

After the fuel poured out of the check valve, the truck wouldn't start. So we pulled the plug, dried it, then it started again. I'm assuming the engine was flooded. I just don't understand how the fuel is making it's way up that vent tube.

I'm thinking the tube may have been pushed in a little to much re-installing the grommet (because we know how much fun that is to install). Thanks for all the help guys! Great forum!
 
Mike4130 said:
So here's my question, my buddy just installed his tank vent (bought the Snappy 3 hole grommet kit from DDM) and ran the vent line 1/2 " into the gas tank. Wen the engine is running gas starts making its way up the tube eventually out the check valve pouring fuel everywhere and flooding the carb. Anyone had this problem? We've tried mounting the valve facing up & down. This is with the cap sealed also. When we run a vented cap, the fuel never rise up the vent tube. How strange is that?
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Mine did this too. It was because I had the fuel lines mixed up. Something to check anyway. Supply to bottom of carb and return out the top.
 
Ebb75 said:
Mine did this too. It was because I had the fuel lines mixed up. Something to check anyway. Supply to bottom of carb and return out the top.
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I double checked that, Thanks.
 
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