Need help with Tanaka 1.75 hp that won't stay running unless on choke

BaconGrease

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Feb 7, 2012
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4
Hi,
New forum member here. I have read through many of the frequently asked questions and previously posted topics but i cannot find help for my problem. I have a tanaka 1.75hp that will only run if its left on choke and if you give it too much gas it then wants to sputter out. I have tore the engine apart and cleaned the rings, opened the carb and let it soak and blew out all of the junk, I have replaced all fuel lines, replaced the spark plug, and made a fresh batch of gas oil mix to use. I cannot figure out what the problem is. This is starting to frustrate me. It worked great the last time I had it running which was about two years ago. I did drain all fuel before storing it.:confused:
 

steelespike

Supreme Mariner
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Apr 26, 2002
Messages
19,069
Re: Need help with Tanaka 1.75 hp that won't stay running unless on choke

Well typically it is a fuel supply problem.Do you have a service manual?You probably notice the carb is a bit of an odd ball.
as the slide admits more air the needle is withdrawn from the jet.Moving the clip up leans the mixture.
Also check that the fuel flows well from the tank.Be sure all passages in the carb are open.
 

robert graham

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Apr 16, 2009
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6,908
Re: Need help with Tanaka 1.75 hp that won't stay running unless on choke

Maybe with a piece of fuel hose, bypass that crappy little petcock that can cause a restriction in fuel flow. I finally just replaced mine with a small black plastic on/off valve from the chain saw/weedeater store. Of course your fuel cap vent is open? That carb and motor is dead simple and if it gets gas, then it'll usually run fine. Good Luck!:)
 

BaconGrease

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Re: Need help with Tanaka 1.75 hp that won't stay running unless on choke

Maybe with a piece of fuel hose, bypass that crappy little petcock that can cause a restriction in fuel flow. I finally just replaced mine with a small black plastic on/off valve from the chain saw/weedeater store. Of course your fuel cap vent is open? That carb and motor is dead simple and if it gets gas, then it'll usually run fine. Good Luck!:)

I already replaced the petcock with a filter and plastic shutoff because it was so crappy. I do have the fuel cap vent open. I have even tried it with the cap off. I'm still stumped:(
 

robert graham

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Re: Need help with Tanaka 1.75 hp that won't stay running unless on choke

Have you tried adjusting the position of the needle in the carb slide to give more fuel?...Still sounds like some kind of fuel restriction/lean condition. Don't suppose that little store-bought filter is restricting the flow?...I use a stainless steel mesh element rather than a paper element filter, which I figured might plug up some...
 

steelespike

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Re: Need help with Tanaka 1.75 hp that won't stay running unless on choke

I already replaced the petcock with a filter and plastic shutoff because it was so crappy. I do have the fuel cap vent open. I have even tried it with the cap off. I'm still stumped:(
Did you check the flow?
 

BaconGrease

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Feb 7, 2012
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Re: Need help with Tanaka 1.75 hp that won't stay running unless on choke

The flow seems fine. I've got one of the mesh filters but I will remove it and try it that way as well. Which way should I adjust the slide needle? The clip is currently on the third groove from the top.
 

robert graham

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Re: Need help with Tanaka 1.75 hp that won't stay running unless on choke

Adjust the clip to raise the needle for more gas through the jet...
 

steelespike

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Apr 26, 2002
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19,069
Re: Need help with Tanaka 1.75 hp that won't stay running unless on choke

I think the 3rd grove is the richest.
 

BaconGrease

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Feb 7, 2012
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Re: Need help with Tanaka 1.75 hp that won't stay running unless on choke

Well I moved the clip down to the lowest (richest) setting and it runs great now. Thanks for all the help. This thing was really frustrating me. Now I can use it on my canoe next week.
 

robert graham

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Re: Need help with Tanaka 1.75 hp that won't stay running unless on choke

That's good!...maybe the clip got moved during the carb cleaning? I've been running a Tanaka 3.0HP on my 17' aluminum canoe since 1983 and it's a great set-up for lots of stuff, especially shallow water fishing! Good Luck!:)
 

Rymer22

Seaman Apprentice
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Feb 7, 2013
Messages
34
Re: Need help with Tanaka 1.75 hp that won't stay running unless on choke

I know im late to this thread but hoping for some help. I too am having this same problem. What is the slide u are refering to? is it the adjustment screw or is ther something else im missing?
 
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