[Rusva]

I got a 2014 rancher 420 fm in trade and they said the rings just needed to be replaced. I bought a new jug, piston, and rings since the old jug was bored and looked scratched. Anyway I get it together with new seals and it won't start. I get a compression reading of 15. When I tried to adjust the valves I could do the intake, but I could unscrew the exhaust side all the way and it wouldn't let me put the guage in at all. Possible my problem is a stuck exhaust valve? I'll post a link to a video of the startup once fb approves it. Hopefully someone can help me out.

 

[shadetree]

welcome. chances are, stuck or bent valve ?, timing not right ?, jumped time, bent a valve ?. anytime they say '' it ran when I last parked it '', or it just needs rings , this tells me..break out the check book !..lmfao. was it sunk ?, any signs of it being sunk ?, best advice, tear into it, and start from scratch !. if its been sunk, and ruined the rings and cylinder ?, you better pull the motor, wash it out very good before you rebuild the top end !?,,,or your going to be right back on here, telling us you rebuilt the top end, it ran for a little while, then no longer will run, then I, we, us...get to tell you..''TOLD YOU SO ''..LOL. not trying to be a butt here ?!, just giving you hard facts .

 

[retro]

I get a compression reading of 15. When I tried to adjust the valves I could do the intake, but I could unscrew the exhaust side all the way and it wouldn't let me put the guage in at all.

You are adjusting the exhaust valve while it is open on the exhaust stroke. Rotate the motor another turn and you'll be able to adjust both of them. Get a copy of the service manual, you'll see what I mean... Welcome to the forums!

 

[Rusva]

I get a compression reading of 15. When I tried to adjust the valves I could do the intake, but I could unscrew the exhaust side all the way and it wouldn't let me put the guage in at all.

You are adjusting the exhaust valve while it is open on the exhaust stroke. Rotate the motor another turn and you'll be able to adjust both of them. Get a copy of the service manual, you'll see what I mean... Welcome to the forums!

I rotated it manually until I seen the T through the hole and the piston was all the way at the top. Should I be looking for a different mark?

 

[Rusva]

Here is the video of startup. It only will start if I give it there slightest of gas and will die if I give it any more.

https://youtu.be/zVeTM_VfdXQ

Also I looked around when I had the top end off with a inspection Cam and it looked clean inside.

 

[Rusva]

welcome. chances are, stuck or bent valve ?, timing not right ?, jumped time, bent a valve ?. anytime they say '' it ran when I last parked it '', or it just needs rings , this tells me..break out the check book !..lmfao. was it sunk ?, any signs of it being sunk ?, best advice, tear into it, and start from scratch !. if its been sunk, and ruined the rings and cylinder ?, you better pull the motor, wash it out very good before you rebuild the top end !?,,,or your going to be right back on here, telling us you rebuilt the top end, it ran for a little while, then no longer will run, then I, we, us...get to tell you..''TOLD YOU SO ''..LOL. not trying to be a butt here ?!, just giving you hard facts .

No hard feels at all man. My trade was only worth $800 and I work on trucks so I figured the whole "it only needs rings" was a crock and I could fix it myself at the cost of parts. I got it when it was already tore down but was still able to turn the key to make sure it atleast semi worked lol. I looked around with an inspection cam when the top was off and it looked clean inside from what I could see. Drained the oil and changed filter and the oil looked okay.

 

[Goober]

There will be two times you’ll see TDC (the T rotates around the first is the compression stroke both valves closed; the second is the exhaust stroke—the exhaust cam lobe is forcing the valve open. I think you’re adjusting the valves not realizing the cam lobe position

 

[shadetree]

I get a compression reading of 15. When I tried to adjust the valves I could do the intake, but I could unscrew the exhaust side all the way and it wouldn't let me put the guage in at all.

You are adjusting the exhaust valve while it is open on the exhaust stroke. Rotate the motor another turn and you'll be able to adjust both of them. Get a copy of the service manual, you'll see what I mean... Welcome to the forums!

I rotated it manually until I seen the T through the hole and the piston was all the way at the top. Should I be looking for a different mark?

there is a great sticky in the repair section from me, I go into easy to understand detail on how to check, and adjust valves on all 4-strokes, please take the time to read it, it's written from a dummy, for dummies..lmfao, no really, very easy to understand for just about anyone . ( word from the wise ) the T mark can be seen from both the exhaust stroke and intake stroke with piston on top dead center !.

 

[shadetree]

welcome. chances are, stuck or bent valve ?, timing not right ?, jumped time, bent a valve ?. anytime they say '' it ran when I last parked it '', or it just needs rings , this tells me..break out the check book !..lmfao. was it sunk ?, any signs of it being sunk ?, best advice, tear into it, and start from scratch !. if its been sunk, and ruined the rings and cylinder ?, you better pull the motor, wash it out very good before you rebuild the top end !?,,,or your going to be right back on here, telling us you rebuilt the top end, it ran for a little while, then no longer will run, then I, we, us...get to tell you..''TOLD YOU SO ''..LOL. not trying to be a butt here ?!, just giving you hard facts .

No hard feels at all man. My trade was only worth $800 and I work on trucks so I figured the whole "it only needs rings" was a crock and I could fix it myself at the cost of parts. I got it when it was already tore down but was still able to turn the key to make sure it atleast semi worked lol. I looked around with an inspection cam when the top was off and it looked clean inside from what I could see. Drained the oil and changed filter and the oil looked okay.

good deal . now, the 64,000.00 question you should be asking yourself ?, IS WHY DOES IT NEED RINGS ??. simple: A : they sunk it ?, b: they ran it with low oil ?. 800 bucks is a good deal, but !!!, I've learned in my 25 plus years of doing this, when things come cheap ?, they add up high !..I know this for a fact !!!..lol. there is nothing cheap about restoring atvs, spec a honda. last atv I restored , 600 bucks up front, 3500 more later..well..you get the pic..lol.

 

[Rusva]

I will try again in the morning to adjust the valves..thanks

also...would the valves cause what is shown in the video i took? it seems as if air is being forced out where the air box connects

 

[shadetree]

I will try again in the morning to adjust the valves..thanks

also...would the valves cause what is shown in the video i took? it seems as if air is being forced out where the air box connects

when air is forced back out the intake ?, this tells me the exhaust valve is not opening.

 

[Rusva]

welcome. chances are, stuck or bent valve ?, timing not right ?, jumped time, bent a valve ?. anytime they say '' it ran when I last parked it '', or it just needs rings , this tells me..break out the check book !..lmfao. was it sunk ?, any signs of it being sunk ?, best advice, tear into it, and start from scratch !. if its been sunk, and ruined the rings and cylinder ?, you better pull the motor, wash it out very good before you rebuild the top end !?,,,or your going to be right back on here, telling us you rebuilt the top end, it ran for a little while, then no longer will run, then I, we, us...get to tell you..''TOLD YOU SO ''..LOL. not trying to be a butt here ?!, just giving you hard facts .

No hard feels at all man. My trade was only worth $800 and I work on trucks so I figured the whole "it only needs rings" was a crock and I could fix it myself at the cost of parts. I got it when it was already tore down but was still able to turn the key to make sure it atleast semi worked lol. I looked around with an inspection cam when the top was off and it looked clean inside from what I could see. Drained the oil and changed filter and the oil looked okay.

good deal . now, the 64,000.00 question you should be asking yourself ?, IS WHY DOES IT NEED RINGS ??. simple: A : they sunk it ?, b: they ran it with low oil ?. 800 bucks is a good deal, but !!!, I've learned in my 25 plus years of doing this, when things come cheap ?, they add up high !..I know this for a fact !!!..lol. there is nothing cheap about restoring atvs, spec a honda. last atv I restored , 600 bucks up front, 3500 more later..well..you get the pic..lol.

$3500 is still cheaper than a new quad :grin i just wanted one to ride around in our woods and for hunting...ill get er fixed up with some help from you guys

 

[retro]

Adjust the valves (both of them) by aligning the "T" mark on the compression stroke instead of the exhaust stroke. You'll know you got it right on the compression stroke when both valves are closed. Read the sticky... read the manual too.

 

[Rusva]

I will try again in the morning to adjust the valves..thanks

also...would the valves cause what is shown in the video i took? it seems as if air is being forced out where the air box connects

when air is forced back out the intake ?, this tells me the exhaust valve is not opening.

parts for a valve job dont seem that expensive...maybe ill just put im new valves and hardware and it will run

 

[Rusva]

Adjust the valves (both of them) by aligning the "T" mark on the compression stroke instead of the exhaust stroke. You'll know you got it right on the compression stroke when both valves are closed. Read the sticky... read the manual too.

just downloaded the manual....ill try to do the valves again in the morning...thanks

 

[shadetree]

I will try again in the morning to adjust the valves..thanks

also...would the valves cause what is shown in the video i took? it seems as if air is being forced out where the air box connects

when air is forced back out the intake ?, this tells me the exhaust valve is not opening.

parts for a valve job dont seem that expensive...maybe ill just put im new valves and hardware and it will run

you can remove the valves with a large socket and hammer to remove the valves and springs ( just make sure to keep an eye out for the keepers !.lol ) but putting the new valves back in will require a valve spring compressor tool. once you get the old valves out, stick them in a cordless drill, run the drill, watch the head, odds are, you will see it wobble if its bent ?!.

 

[shadetree]

No hard feels at all man. My trade was only worth $800 and I work on trucks so I figured the whole "it only needs rings" was a crock and I could fix it myself at the cost of parts. I got it when it was already tore down but was still able to turn the key to make sure it atleast semi worked lol. I looked around with an inspection cam when the top was off and it looked clean inside from what I could see. Drained the oil and changed filter and the oil looked okay.

good deal . now, the 64,000.00 question you should be asking yourself ?, IS WHY DOES IT NEED RINGS ??. simple: A : they sunk it ?, b: they ran it with low oil ?. 800 bucks is a good deal, but !!!, I've learned in my 25 plus years of doing this, when things come cheap ?, they add up high !..I know this for a fact !!!..lol. there is nothing cheap about restoring atvs, spec a honda. last atv I restored , 600 bucks up front, 3500 more later..well..you get the pic..lol.

$3500 is still cheaper than a new quad :grin i just wanted one to ride around in our woods and for hunting...ill get er fixed up with some help from you guys

bought a 2003 trx450fm awhile back, paid 300 bucks, 5 hour drive round trip, 4500 bucks later, shes a new atv, and not for sale !..lmfao.

 

[Rusva]

Okay so I got the valves adjusted, but I still can't get it to start. I know I have fuel because I took the carb off and see it spraying gas, I should have air because I don't have the air filter box connected right now, and I confirmed I have spark so....

I believe my battery is bad since I have to have it hooked up to cables to turn it over...but that shouldnt stop it from starting...I'm at a loss right now

Also...when I first turn the key on and try to start it I get compression at 60...but when I try to start it again it goes to 30. I can turn off the key and turn it back on and it will always test at 60 when the key is turned off then on...

 

[shadetree]

at 60 psi, it will never run.

 

[Rusva]

at 60 psi, it will never run.

Yeah...I think it has to do with the valves so I will order new parts and replace them...cross fingers that fixes it