[chrisbaker]

Good morning,

I am a new member to this forum and am really stumped. I have a 2003 RancherES that was running fine and the stopped. I was able to get it going several times of a couple of days, but eventually dies. Here is a list of what I have done so far.
drained and cleaned gas tank, replaced carb twice, cleaned spark arrestor, replaced in line fuel filter, replaced spark plug.

I have fuel flow, spark and when choked and primed it almost fires but not quite, even with ether. I am really stumped on this one as this is the first ATV I've owned. Just wondering if there is a timing issue or some electronics I'm missing. Any help would be really appreciated. Don't want to take it to a shop as the repair bill may exceed the value of the vehicle.

Thanks
Chris

 

[Black0ut]

Compression is good? Should hit on ether otherwise I would think.

 

[SamUK]

When you say 'replaced carb twice' do you mean cleaned the carb or replaced it completely for a new unit?
If it's a new unit is it an OEM or Chinese junker? If Chinese, honestly, you may as well throw it in the bin and cut your losses, they really are that bad. A quality name Carb rebuild kit for your OEM carb is definitely the way forward.

 

[mrbb]

FIRST OF WELCOME TO THE SITE!

NEXT? how many hours miles on this atv< jumping time can happen with some age or abuse or??

also, what is the compression at?
ATV ever sunk??

and I agree , explain more on "CARB replaced twice"
I agree many time Aftermarket carbs can be JUNK!



if compression is good, and timing right, you MIGHT have a bad CDI, causing funny things at time to start and or run!

 

[chrisbaker]

I don't know what the compression is. It's at a buddy's house now and he will check it tomorrow. I purchased two new carbs, interestingly both seem to leak from the primer when pressed several times, one was a Leland? They were like $50 (the first one didn't have a heater but did work for about an hour before it failed completely. As to the question of ever sunk, no idea. I bought it used and it was a farm vehicle and has been patched together many times by my reckoning and I'm sure it has been completely abused, but it did run fine for a couple months since purchase.

What is the CDI? and how do you adjust timing? When you turn it over, it almost wants to start to the point where the exhaust gets warmish so there is combustion at some level. It seems like an exhaust blockage or timing issue, but I don't know how to adjust the timing as there is no distributer and I tried to start it without the muffler to no avail. BTW, you guys are awesome with your responses, thanks

Chris

 

[chrisbaker]

Oh, probably many hours and many miles. The guy that sold it to me said it was a 2003, no title and can't find any vin or id info on the vehicle

 

[Black0ut]

Vin should be around the front "bumper area" engraved in a flat on the frame. I would start with a compression check. Might have jumped time or engine needs an overhaul.

 

[SamUK]

Check list...

Check timing
Compression test
Thoroughly clean and refit OEM carb (check fuel tank for debris before refitting!)

CDI controls spark, ignition(timing) advance and rev limit.

 

[retro]

Got a copy of the FSM yet? Welcome to the forums!

 

[mrbb]

yes GET a service manual, you will learn a lot from that alone

NEXT< if the VIN is MISSING< that is a HUGE RED FLAG, its against the law to have one removed, and HIGHLY increases the odds its a stolen atv>
if your CAUGHT with it, they can confiscate it off you, and any money you put into it, will be a 100 % LOSS to you
SO< before I'd go sinking money into this, I'd make darn sure it HAS a VIN< as well, as maybe have the vin run, if its altered in any way.

IF this atv was ever sunk, DOES it look like this is a possible thing??
running a motor AFTER it was sunk, EVEN if it was " flushed " or NOT, can be a short lived motor on you,
if its low on compression, and you even THINK, it MIGHT have been sunk, its going to need a full break down and cases split and things inspected inside and cleaned SUPER well!.

as they say your call, you can just get it running and ride it to death LOL , or, can fix it right and get many many yrs out of it?

 

[chrisbaker]

Sorry for the delayed response. Looks like the motor is done. Compression around 35psi, with the valves seated, compressed air is clearly audible in the crankcase. What in your opinions is the most cost effective solution for a rebuild? Big bore kit? used replacement engine? $.75/lb at the scrap yard?

 

[Jeepwm69]

If you have a good local machine shop, take the cylinder to them, have them measure it and order the appropriate oversized piston, and then they will bore the cylinder to match the new piston.

If you don't have a good local machine shop, G&H discount ATV is good to go. Shipping adds quite a bit to the price, but they do good work.

Another alternative is something like this. I don't know anyone who has tried one. Price is definitely right, but I'm sure it's Chinese, and it strikes me as one of those "too good to be true" cases.

HONDA RANCHER TRX350 TRX 350 CYLINDER PISTON RINGS GASKET KIT SET 2000-2006 | eBay

I've thought about trying one simply to settle the "Does it work or not" question that arises here from time to time.

 

[chrisbaker]

pretty sure it was never under water, just an old and abused vehicle. Have not looked for vin, but I get it back from my friends tomorrow and will check then. Are there crank bearings and cams/timing chain that should be replaced also or does a new piston and valve lap do the trick. Also if just the top end and piston does the motor need to be removed or can you do it in place? I have worked on cars for a long time but never an ATV and I don't have a real baseline for how complex they are onside and all the tips and tricks. Thanks for all your help and advice, it is really appreciated.

Chris

 

[retro]

You can do it all while the motor is in the frame, but its a lot easier to work on while its out, since so much of the motor will be taken apart and fussed around with. I'd take it out first if I were working on it, if for no other reason than to be able to work on it off the bench. My eyes are not good anymore... and my back and my hands are shot too. 30 years ago I could do whatever saved the most time, but nowadays gotta worry about whether I can actually get the job done or not before my body breaks down. Then there are those unknown issues that tend to pop up more often when I'm taking a shortcut... like what if the little end of the rod is worn out...or some other surprise? With an already sore back and aching hands I'll end up pulling the motor & splitting cases anyway! Your call...

No matter what you decide, the service manual be your best friend during the entire job. Unless you are very experienced lots of your money and time can/will get wasted winging it...

 

[Jeepwm69]

The 350 motors are pretty easy to yank. Unbolt front diff and pull it forward so you can pry the front driveshaft out and then unbolt the two lower motor mounts and one upper motor mount, unbolt exhaust and oil cooler lines, and out it comes.

You can do it in the frame fairly easily too, but on a 350 I usually pull the motor since they're not big and heavy.

 

[chrisbaker]

Awesome guys, that's good advice as I usually cause myself as many headaches trying to save time as any upside I might achieve. sounds like a good fall project when the kids are back in school and I can get some of my day back. I hear you on the body breakdowns, my eyes don't work up close and more and more far away, but at about 5-10 feet, I'm awesome. lol. I'll download the manual and get my ducks in a row, thanks for all your help on this one, I already feel tons more informed

 

[retro]

Thanks, feel free to start another thread and keep us updated as you're having all that fun, if you can! Many of us here like to follow along and look at pics...