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Discussion Starter · #1 ·
Here is the story of my troubles. I bought a 98 fourtrax 300fw about a week ago, it was not running when i bought it but was used all winter to plow snow and had been running within the month. It came with a broken starter valve in the carb and a broken exhaust flange bolt so it has an exhaust leak from the head. So I brought the atv home and cleaned the carb and put new jets, needles and gasket/o rings in it. New spark plug and now she will fire but wont idle just dies immediatly, cant get her to run at all. The starter valve is 50$ and i dont want to buy it until I know if the atv runs, I dont have the money to spare right now. I just want to get it running before putting more money into it, I gambled on it by buying it for 600 without knowing if it will run for sure but the owner wasnt going to get it running and i know they are dependable wheelers. I already made sure the vents were clear and the tank is vented. If anyone has some ideas i would be greatful for the input.
 

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as I said in PM, fix the choke valve, clean the carbs jets, then take it from there. it won't run without the choke valve fixed, because it will suck air.
 

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With the carb off you can spray starter fluid straight into the intake. Spray intermittently to keep it running. You can hear knocks and rattles during this process. Then you will know if it will be worth the time and money.
Starter fluid is known as 'knock knock' here in the UK, basically because that's what it does to engines in such a short time! It ruins them, will also cause a knock,pink & rattle when spraying into the intake.
I'd personally put gas(petrol) into a spray bottle and take it from there.

It's each to their own obviously but if I see anybody using knock knock i cringe, bigtime!
 

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You could also pour a little gas (petrol) down the plug hole and fire it that way a few times, if the exhaust is blowing at the head though I doubt you'll hear much in the way of an engine issue.
 

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With the carb off you can spray starter fluid straight into the intake. Spray intermittently to keep it running. You can hear knocks and rattles during this process. Then you will know if it will be worth the time and money.
Starter fluid is known as 'knock knock' here in the UK, basically because that's what it does to engines in such a short time! It ruins them, will also cause a knock,pink & rattle when spraying into the intake.
I'd personally put gas(petrol) into a spray bottle and take it from there.

It's each to their own obviously but if I see anybody using knock knock i cringe, bigtime!
this starting fluid topic has been covered soooooooooo many times !. once again , i'll say all over. you can use starting fluid as a TESTING method ONLY !. the trick here is, NOT SPRAYING A LOT IN THE INTAKE !. why ?, because starting fluid washes away oil from the cylinders walls, you do not want this to happen !. again, SHORT BURST ONLY !!!, DO NOT KEEP SPRAYNG IT IN TO KEEP THE MOTOR RUNNING !!!..THIS IS A BIG NO NO !!. in my 20 years of building/restoring atvs/engines, NOT ONCE HAVE I DESTROYED A MOTOR BY USING STARTING FLUID !. starting fluid is great for only one thing ?..FOR TESTING TO SEE IF THE MOTOR FIRES OVER, WITH COMPRESSION ?..other than this ?..DO NOT KEEP SPRAYING IT IN THE MOTOR !!.
 
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With the carb off you can spray starter fluid straight into the intake. Spray intermittently to keep it running. You can hear knocks and rattles during this process. Then you will know if it will be worth the time and money.
Starter fluid is known as 'knock knock' here in the UK, basically because that's what it does to engines in such a short time! It ruins them, will also cause a knock,pink & rattle when spraying into the intake.
I'd personally put gas(petrol) into a spray bottle and take it from there.

It's each to their own obviously but if I see anybody using knock knock i cringe, bigtime!
this starting fluid topic has been covered soooooooooo many times !. once again , i'll say all over. you can use starting fluid as a TESTING method ONLY !. the trick here is, NOT SPRAYING A LOT IN THE INTAKE !. why ?, because starting fluid washes away oil from the cylinders walls, you do not want this to happen !. again, SHORT BURST ONLY !!!, DO NOT KEEP SPRAYNG IT IN TO KEEP THE MOTOR RUNNING !!!..THIS IS A BIG NO NO !!. in my 20 years of building/restoring atvs/engines, NOT ONCE HAVE I DESTROYED A MOTOR BY USING STARTING FLUID !. starting fluid is great for only one thing ?..FOR TESTING TO SEE IF THE MOTOR FIRES OVER, WITH COMPRESSION ?..other than this ?..DO NOT KEEP SPRAYING IT IN THE MOTOR !!.
I should imagine it has lol.

Starter fluid contains ethanol, ethanol eats metal in a matter of hours wether it's a lot or a little, it's still a fact. Hence why drag cars a rebuilt for every race!
If the OP doesn't know the condition of his engine advising to use easy start isn't a wise idea is it, he could finish it off and be left with a knackered motor.

Stick with gas in a spray bottle, it works just fine!
 

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from my personal experiences with starting fluid , it is like a loaded gun , in the hands of the wrong person and used wrong it can be fatal , I have seen people destroy diesel engines with it , I use it , it is a helpful tool if used in small burst
 

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If you use starting fluid or petrol it's muy importante not to allow free fluid to accumulate--if your carb backfires you could burn down your rig and the garage!
Have a thick towel ready to smother any flash if you use this method.

Starter valve is only $35 I know you're concerned about the dollars, but you'll be much more satisfied with proper fixes.

A good starter valve makes a huge difference but I'm not going to promise that you won't have to make more repairs. BTW $600 for that rig is a great deal
 

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Discussion Starter · #10 ·
Thank you all for the replies, I finally got some free time and I am going out to try the gas spraying into intake.

Shadetree, i didnt get to compression test it because i dont have a small enough adapter, the bowl is filling up i checked by opening the drain screw and it flows out of drain hose.

The local honda dealer here wants 50 for the starter/choke valve and if the engine sounds good i will definately buy it when i can, its just i dont want to throw 50 at a part for the carb to find out the engine needs a rebuild, if that makes sense.

I will check back in after i go spray gas into intake.
 

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Discussion Starter · #11 ·
So gave squirting gas into the intake a shot, if i nearly stick the nozzle of the bottle in the intake it will fire between 1-3 times. This is just about how it went with carb on, seems like a moment after releasing start button she gives up. With attempting to pulse gas in to keep her running i cannot get it to stay puttin, a few back fires of gas vapor out of the intake though no fire. Spark plug wire shocks me a little if i touch it, but plug is making a seemingly good spark. Still stumped.

In the case of the strarter valve, i have it in the carb and use the plastic screw cap and some paper towel to hold it in position/(what i assume is) fully disengaged (fully pushed into the carb). Shouldnt i be able to get it to run like this? It has been in the 60s here (northern Mn). I have a few things to do today but if i have time i may clean the carb for the 4th time tonight.
 

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sounds like your c.d.i. is mis-firing ?, not sparking all the time ?, put the spark plug in the boot, lay It on the engine rocker, crank it over, watch to see if it sparks while holding the button ?. if it does ?, then its a fuel issue. if it does not ?, then this is a electrical issue, as in c.d.i., stator, reg/rec.
 

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Discussion Starter · #14 ·
sounds like your c.d.i. is mis-firing ?, not sparking all the time ?, put the spark plug in the boot, lay It on the engine rocker, crank it over, watch to see if it sparks while holding the button ?. if it does ?, then its a fuel issue. if it does not ?, then this is a electrical issue, as in c.d.i., stator, reg/rec.
it sparks, one of the first things i tried but i just tried again
 

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sounds like your c.d.i. is mis-firing ?, not sparking all the time ?, put the spark plug in the boot, lay It on the engine rocker, crank it over, watch to see if it sparks while holding the button ?. if it does ?, then its a fuel issue. if it does not ?, then this is a electrical issue, as in c.d.i., stator, reg/rec.
it sparks, one of the first things i tried but i just tried again
ok, your getting spark. then this is a fuel issue. you should go back through your carb, there is a sticky on this, i'll copy and paste it for you, please read it, read it again, and understand it :).
 

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Discussion Starter · #20 ·
Just got done cleaning carb again following shadetree's how to and installed the new choke valve deal, still no luck. Starts if i pump the plunger on the bottom of the carb then dies within a second or two, seems to be having a hard time getting the fuel from the carb into the combustion chamber. Still stumped, to recap what ive done; cleaned carb 4x now, new plug, and broken starter/choke valve replaced. All vent lines are clear cap vent works and bowl fills up with fuel. Last couple times cleaning carb havent found any evidence of debris at all, oh yeah and put a repair kit into carb, new pins and new o rings and gasket. ??
 
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