vapor lock on cali 6.5?

jdogg

jdogg

#1
#1
OK guys need your input on this! I have the Harbor Freight 6.5 with all the C.A.R.B. crap on it and read somewhere on here just to take it off and plug the 1/4'' inlet or outlet on the gas tank. OK did that now it seems its starving for fuel will only start with choke and dies within a few seconds. Thought It might be outa gas/ took off cap/ nope got gas/put cap back on/ starts and runs fine!! My guess is that little inlet also lets the tank breath. So I took the plug off today and it sucked air into the tank/ so I put a dirtbike/atv breather tube on it that should solve the problem! Hav'nt had a chance to try it out yet maybe this weekend:shrug:I'll let you guys know!Just wondering if anybody else ran into this problem? Sorry its so long I have a bad habit of not being able to get to the point!!:eek:ut::laugh: Thanks!!:thumbsup:
 
jdogg

jdogg

#2
#2
OOOOPS!! Sorry Chris this should have gone into engines and modifications feel free to move it! But in my defense the 6.5 in question is on a doodlebug!:laugh: Thanks!!
 
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Lorne

New Member
#4
#4
The EPA spec (49 state) engines have a gas cap that vents, and the California engines have a type of evap system in order to prevent the fuel vapor from escaping, and the cap does not vent. When you plug the evap lines on a California model, the tank develops a vacuum and fuel can't free flow. Kind of like when you hold water in a straw by putting your thumb over the top.

When you remove the gas cap, the vacuum is released and fuel flows again.. until you put the cap back on.

The evap setup won't hinder engine performance.. there's really no gain to be had by disconnecting it..
 
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Lorne

New Member
#6
#6
I agree. It's a lot of clutter. That's why I got rid of my stock tank completely.

The breather he installed will probably fix the problem. If not, I would either drill a tiny hole in the cap so it can vent (be careful with this because if it's too big it will always leak gas), or get rid of the tank altogether and find a different tank with a vented cap (like a round tank). That's what I did.
 
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bheezy27403

New Member
#8
#8
Lorne, I have a stock clone (N.C.) and I believe I may be experiencing some vapor lock. How small of a hole (in the cap) are we talking here? All replies appreciated. B
 
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Lorne

New Member
#11
#11
That's a good size (1/16 is like the diameter of a toothpick), but I have to ask.. Have you tried running the engine with the gas cap removed?

If you take the cap off and you still have issues, drilling a hole wont help.
 
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E85TunedGX200

New Member
#13
#13
Why not just leave on the vacuum line attached to the top of the fuel tank? Doesn't it just route to the black canister - allowing air to be drawn in - so that the fuel tank can breathe?
 
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