[Narco83]

Hello all! I'm new to the site as well as atv's. I actually obtained my first one yesterday which is a '98 Fourtrax 300 4x4 which I traded a johnboat/trailer setup for.

I picked it up yesterday with the understanding that it needed a battery but would kick over and run fine. I watched the previous owner hop on and kick it over with no problem. It only took two kicks. We loaded it up and I brought it home.

When I got home I unloaded it and hopped on. I kicked until I was exhausted. Yes the key was on, switch on run and the fuel on. Being that I unloaded it in the field next to my house, I slowly towed it over to my house to put in the garage, probably about 400 yards that it was towed.

I then said screw it, went and bought a battery. Put the battery in and it turns over but won't crank. I tried kicking again and nothing. I originally tried with no throttle, then light throttle. I messaged the guy I got it from and he said hold it wide open and kick it. Tried that too and nothing. I even used some starting fluid but no change.

Being how it's old and worn out, I intend on doing a long term rebuild. I Removed the rear fender and air box. Drained the fuel and put in fresh non ethanol. I turn it over and I noticed a lot of compression/pressure coming out of the carb which sprays a little fuel. Is this normal?

Also note that the choke cable is broken. I have one on order as well as a carb kit to freshen it up. But it's also around 95 degrees here in south GA. The previous owner claimed to have just done a top end. I have no reason to doubt that.

Basically I'm looking for any advice. I did test spark and compression. Both are good. If the compression through the carb is normal then I am going to have higher hopes with the carb rebuild.

Sorry for any stupidity I may have posted. As I said, I am new to atv's. I haven't had anything since I used to race motocross on 2 strokes back in the day.

Thanks in advance.

 

[retro]

Nothing you said is stupid! LOL You traded for an unknown basically. So we can either sit here and guess all day what may be wrong with it (I can think of 7 things possible right now, simple & dumb stuff excluded!) or you can go through it and fix everything up right before trying to ride it. Get yourself a copy of the FSM HERE if you've haven't gotten it yet.

Then pull the tank and clean it out. Pull the carb down, clean thoroughly and reassemble exactly as the FSM recommends & making sure the vent hoses are all clear. Put a new NGK spark plug in it. Check the wear on the timing chain. Adjust the valves. Change fluids & filters etc. Replace any broken, missing or worn out parts that you find... When you get done it will probably start right up and run good. If it doesn't, the cam chain may have been installed out of time or has jumped a tooth.

Welcome to the forums!

 

[shadetree]

new top end huh ?, well bro, this tells me a few things !. one: compression not high enough ?, two : timing from cam to crank is off ?. I say timing !, why ? : simple, no fuel should spray from the carb when cranking it over, at least not much until its running. exhausting out the carb tells me the timing is off from him doing a top end rebuild ( if it was really done ??!! )..lol ..

 

[Narco83]

Nothing you said is stupid! LOL You traded for an unknown basically. So we can either sit here and guess all day what may be wrong with it (I can think of 7 things possible right now, simple & dumb stuff excluded!) or you can go through it and fix everything up right before trying to ride it. Get yourself a copy of the FSM HERE if you've haven't gotten it yet.

Then pull the tank and clean it out. Pull the carb down, clean thoroughly and reassemble exactly as the FSM recommends & making sure the vent hoses are all clear. Put a new NGK spark plug in it. Check the wear on the timing chain. Adjust the valves. Change fluids & filters etc. Replace any broken, missing or worn out parts that you find... When you get done it will probably start right up and run good. If it doesn't, the cam chain may have been installed out of time or has jumped a tooth.

Welcome to the forums!

Thanks for the link and advice retro. You are 100% correct about doing it all right myself. I think I'm more annoyed that it ran for him but I can get it to do anything lol.

 

[Narco83]

new top end huh ?, well bro, this tells me a few things !. one: compression not high enough ?, two : timing from cam to crank is off ?. I say timing !, why ? : simple, no fuel should spray from the carb when cranking it over, at least not much until its running. exhausting out the carb tells me the timing is off from him doing a top end rebuild ( if it was really done ??!! )..lol ..

Thanks for the input. I think I'm going to plan to go ahead and change the cam chain too. Better safe than sorry.

 

[SamUK]

If you plan on fitting a new cam chain be sure to fit a new cam chain gear at the same time, another member recently had issues by only changing the chain, as did I.

 

[shadetree]

Nothing you said is stupid! LOL You traded for an unknown basically. So we can either sit here and guess all day what may be wrong with it (I can think of 7 things possible right now, simple & dumb stuff excluded!) or you can go through it and fix everything up right before trying to ride it. Get yourself a copy of the FSM HERE if you've haven't gotten it yet.

Then pull the tank and clean it out. Pull the carb down, clean thoroughly and reassemble exactly as the FSM recommends & making sure the vent hoses are all clear. Put a new NGK spark plug in it. Check the wear on the timing chain. Adjust the valves. Change fluids & filters etc. Replace any broken, missing or worn out parts that you find... When you get done it will probably start right up and run good. If it doesn't, the cam chain may have been installed out of time or has jumped a tooth.

Welcome to the forums!

Thanks for the link and advice retro. You are 100% correct about doing it all right myself. I think I'm more annoyed that it ran for him but I can get it to do anything lol.

tip for ya : I have a golden rule when it comes to buying an atv or any thing with a motor ? ( spec atvs or motorcycles ), I always...ALWAYS !!..when I get there ?, the very first thing I do ?..IS I PUT MY HANDS ON THE MOTOR, AND SEE IF IT'S WARM OR COLD ??!!!. a warm engine tells me this motor has starting issues ?, or..he wanted to make sure it runs when I get there ?. if a sellers claims it runs just great ?, THEN THERE SHOULD BE NO REASON THAT THE MOTOR WILL BE WARM OR HOT !!!!!.

 

[shadetree]

side note: I don't worry if they run or not ?, 10 out of 10 times..i buy non-running atvs/motorcycles anyway !!..lol. ( cheaper for me to buy them this way )..one thing is for sure ?..I WILL MAKE THAT MOTOR RUN AGAIN !..LOL.

 

[retro]

I do like shadetree does, get them cheap (or free) and fix them up!

I do it differently than many others do though... I don't even try to start most of the things I bring home! Why not? Because it doesn't matter to me whether they will run or not... they aren't ready to start and be used yet!

I disassemble everything on the machine and put it back together right, freshly lubed and adjusted and with any new parts I find that it needs. Then, when it is time to use it, I KNOW for a fact that nothing is getting torn up, that it needs nothing, and that it is ready to be put to work... and requires no more of my time and money!

I hate chasing problems, they get expensive and waste my time. If I don't put eyeballs on everything, many problems can remain unknown until something blows. So I refuse to chase...

About your fuel spray and/or carb standoff... check all of the vents and vent hoses on the carb for mud daubers nests and blow them all out clean as part of your carb cleaning job. Heavy fuel standoff while cranking is generally caused by plugged atmospheric vents.

And even though you have already checked compression and found it to be good, snoop in on the intake valve if you take the rocker cover off and decide whether it can be sticking open or not. Valve guides can fill up with crusty oil over time from decaying valve seals and stick open on occasion.

You can check your timing chain for wear by turning the motor over to TDC on the compression stroke, then take the chain tensioner out. While holding the tensioner back in against the guide after it has extended itself, you can see how much wear there is left to it.

Ask questions if you have any and enjoy your work!

 

[SamUK]

Compression stroke TDC will be when the cam lobes are facing down, also, may sound silly but it's an easy thing to do, did you test the compression with the throttle wide open?

 

[shadetree]

Compression stroke TDC will be when the cam lobes are facing down, also, may sound silly but it's an easy thing to do, did you test the compression with the throttle wide open?

'' did you test the compression with the throttle wide open '' <----- this is a MUST DO... IN ORDER TO GET A CORRECT READING !!!!.