4-Stroke Valve Spacing Guide

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Earth Mechanic

Guest
Hey Crew, Sorry so long since the last post, duty called. I have put serious mileage on my honda gxh50 4 stroke after regapping the valves (300+ miles) and found out that bigger valve gaps on the intake and exhaust is both easy to adjust and makes a big difference in accelaration and top speed (aka more of both). Follow the pics to regap your valves.

I have also included pics of two gasket makers that will work, but are not recommended, as the red gasket maker has melted off my crankcase and head cover.

Emech
 

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MadPC

Guest
Hey Earth Mechanic, this is a great post... Thanks for being the few w/ the honda 4 stroke here.

In fact I have the same engine too but I'm running into this "stalling problem" right now and i wonder if you have any advises for me.

I get the engine brand new and I did not run for over 3 miles. One day I was trying to work w/ my gear box, I angled the bicycle 90 degrees up and some of the gasoline leaked out(I think it's from the carb)... then after that the stalling problem was introduced. The bike would stall while throttling...

I then took out the the carb, cleaned it and rebuild it... the bike stalled even quicker then b4. I started it up, 2 sec later it died.

I checked the fuel tank and filter, there is no clog..

I checked the wiring, they are all good... the spark plug is good as well...

So here is the question, when you get your new engine, after you connect the fuel input w/ the tank, did that take you a few days to let the fuel "soak" into the carb bowl? Or it happened instancely?

This situation I have seems to related to low fuel in the carb bowl. So does it take the carb a few day make the gravity to push the gas down the bowl?

I ordered and replaced the engine a new carb it's still no good. It starts for 2 sec and died. I wonder if I need to wait for the gas to soak into the carb bowl...

Would the carb gasket blocked part of the pressure regularing holes? would that matter?
 
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HoughMade

Guest
I have the GXH50 not installed yet. I was able to test run it by filling the fuel bowl with a syringe, then it would run until the bowl emptied. I did this several times. It sounds to me like your float is stuck or wedged in some way. However, it would seem that your carb rebuild would have addressed that...unless all your work was internal to the carb and not in the bowl.
 
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MadPC

Guest
hey where did u syringe the gasoline to? the main gas nozzle or the fuel valve?
 
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MadPC

Guest
I did both...
I first try to clean it and rebuild it... the problem was still there... then I order one from ebay and put the new one there
it's still the same...
 
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dave1490

Guest
Hey Crew, Sorry so long since the last post, duty called. I have put serious mileage on my honda gxh50 4 stroke after regapping the valves (300+ miles) and found out that bigger valve gaps on the intake and exhaust is both easy to adjust and makes a big difference in accelaration and top speed (aka more of both). Follow the pics to regap your valves.

I have also included pics of two gasket makers that will work, but are not recommended, as the red gasket maker has melted off my crankcase and head cover.

Emech

this doesn.t make sence. increasing the gap would give you less lift and deration.quicker for the bottem end but not more speed.the best way is to adjust when running to just befor the ticking stop,s to compensate for thermal expantion.
 
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Alaskavan

Guest
Hey Mad, are you getting fuel from the tank to the carb? If it's gravity feed, if you pull the fuel line off the carb, there should be a good flow of fuel. It should not take days to fill the carb.
 
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MadPC

Guest
yea the fuel come out fine if I pull the gas pipe out from the carb...
 
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Earth Mechanic

Guest
thanks for the reply dev,

It does seam like it would decrease compression by opening up the valves. I also really didnt change the spacing by more than .5 mills, so maybe im just smokin. It does seam like tighter valve gaps would create more compression and top speed....Do you really recommend adjusting the valve gap while running, seams like it wouldbe tough to get the feeler guage in there with all the motion, but perhaps i just ditch the feeler and adjust the motor based on throttle sound?? teach me more.
 
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