[AndyB]

I picked up an 86 four trax 350 4x4 a week ago from a buddy. It hadn't ran in a couple years. So, I did the normal change fluids and filters. I couldn't get it to start, so I just adjusted the valves. I had to turn each screw at least 2-4 turns to get the feeler gauge in there. So, I was wondering if any of you thought that might have been to much? I had the correct gauge, well actually it was .078mm. But as soon as I put everything together, I tried to start it with the starter and it wouldn't start. So, I tried the kick starter and after probably the 7-8th try it came to life! So, I took some vid of it b/c it sounds like I have the valves to loose, but I'm not an ATV guy so I don't know.

Can someone take a listen and tell me what they think? Sorry for the quality, I took it with my iphone and photobucket sucks with degrading the quality.







Thanks,
Andy

 

[Helmut]

In the video, it sounds like they are too loose and 2-4 turns seems like a lot to have to loosen them. Did you have the piston on TDC on the compression stroke?

 

[AndyB]

Yeah I'm pretty sure it was the compression stroke and TDC. I put a long screwdriver in the plug hole and lined up the "T" mark with the mark in the case when the piston was at TDC. Did I do it right?

 

[Helmut]

Yeah I'm pretty sure it was the compression stroke and TDC. I put a long screwdriver in the plug hole and lined up the "T" mark with the mark in the case when the piston was at TDC. Did I do it right?

Yeah, sounds like you did it right. In the video, they sound too loose, though. I don't know what happened.

 

[TRX2fiveO]

oh yeah way too loose bro. if you rotate it around to TDC with the "T" alligned feel of the exhaust rockers if it is tight rotate it around again to the "T" then feel the exhaust rockers again whichever is the looser is where you want to adjust.

 

[AndyB]

oh yeah way too loose bro. if you rotate it around to TDC with the "T" alligned feel of the exhaust rockers if it is tight rotate it around again to the "T" then feel the exhaust rockers again whichever is the looser is where you want to adjust.

Yeah, it dawned on me after I posted the thread that I probably didn't do it on the right stroke. I didn't pay attention to the rockers to see which one was moving on the upward stroke to see which part of the cycle I was on. At least I got it to fire, so now I'm not so worried the motor is bad. Will be readjusting tonight. Going to stop by the shop and get a better feeler gauge too.

Thanks guys, much appreciated.

 

[Helmut]

I didn't figure it would even start if he adjusted the clearance on the exhaust stroke, because the exhaust valve would be all the way open and the rocker would be on the cam lobe. I don't even see how he could have adjusted them enough to have any clearance between the valve stems and the rocker arms when the lobes on the cam are facing up and the exhaust valve is open. The valves would have to shut all the way while the cam lobes are facing up to have any clearance. And if he did get any clearance with the lobes up, when the cam turns back around again, it won't open the exhaust valve at all. I guess the intake valve would be pretty close on the exhaust stroke, since it would be closed. That don't make sense to me, but maybe I'm missing something. Maybe he adjusted them on the "F" mark instead of the "T" mark. It's hard to see those marks sometimes.

 

[Helmut]

There's a "T" mark and a "F" mark. Make sure you adjust them on the "T" mark with the lobes on the cam facing down. Also, make sure the engine is cold when you adjust them.

 

[AndyB]

There's a "T" mark and a "F" mark. Make sure you adjust them on the "T" mark with the lobes on the cam facing down. Also, make sure the engine is cold when you adjust them.

Will do. Engine was def cold. I think it last time it was started was 3 years ago. lol

 

[Helmut]

There's a "T" mark and a "F" mark. Make sure you adjust them on the "T" mark with the lobes on the cam facing down. Also, make sure the engine is cold when you adjust them.

Will do. Engine was def cold. I think it last time it was started was 3 years ago. lol

Yep, it was definitely cold then, LOL.

I don't know how well you can see through those valve adjusting holes, but try to look at the cam and see if the lobes are facing down. When you adjust them, you don't want the rockers sitting on a lobe.

 

[AndyB]

We have success. Tore it back apart and checked the valves. I did it right the first time, I guess the issue was that the motor had sat for 3 years w/o being started that everything was so tight. When I adjusted them the first time I guess I had them loose enough to let the motor start and break the "rust" off everything to get it back loose again. B/c when I went back in this time to adjust them I could'nt believe how much play I had in the valves. So, I readjusted, put it back together, and fired it up and it sounded much much better. Let it run for about 5-10 min and start to burn off all the crap that's built up over the years. I'm going to readjust them again tomorrow and see where they are when I pull it apart. I'll keep doing this until it sounds the way I think it should. I've got two weeks until a family camping trip that the wife said I have to have it running for, so she can ride it. lol

Anyway, my next question is, what do you guys think of this fuel pump? It's wired directly to the fuse and there is no regulator that I can see inline, unless it's electronic. My thinking is that it could eventually flood the carb if it idles for a little bit. When I'd rev it, fuel would come out of the carb a little.

I really appreciate all your guys help! I know cars like the back of my hand, but ATV's are a new world to me. This is my first, which is why I bought this one.

 

[Helmut]

Glad you got the valve clearance figured out. As far as the fuel pump goes, it has a relay/control unit that operates the fuel pump and I think it cuts the fuel pump off and on when needed. I'm not sure about that, but I believe that's how it works. Whoever hooked that fuel pump up must not have hooked it up through the relay/control unit. You can see the fuel pump relay in the diagram below. It's the box on the left side of the diagram at the top. The fuel pump is directly under the relay in the diagram.

 

[TRX2fiveO]

If you turn on the key while holdong the pump does it pulse for a second or two then shut off? and while its running do you feel it pulsing? I doubt it will cause any issues I would start it up and let it idle for a few min and see if it's loading up if it is you and buy an aftermarket regulator and drop the fuel pressure below the 2.5 minimum psi the pump puts out. but you may run the risk of shoting out the pump. the cost effective thing to do would be to replace the pump with the factory one and save that one as a transfer pump for cars at the mall parking lot...lol JK

 

[Helmut]

the cost effective thing to do would be to replace the pump with the factory one

I don't think the factory fuel pump is available for that ATV anymore.

 

[TRX2fiveO]

hmmm well that would pose to be an issue then wouldn't it?? LOL. what psi is the stock pump operating at Helmut? that would tell him if it is working correctly.

 

[Helmut]

I looked through the manual and I can't find anywhere in the manual where it tells the fuel pump pressure. All I could find was a volume test, it didn't have a pressure test.

 

[Helmut]

Also, here is the procedure for checking the fuel pump cut relay.

 

[AndyB]

Thanks a ton guys. I'll check out if the relay is even still there tonight and check to see if it's still good. If it is, I'll wire it back in and we'll see how it runs. This is prob the most helpful board I've been on in a while. Many thanks!


The pump stays on all the time. It's wired directly to the power. As soon as the key is on the pump is on.

 

[AndyB]

Checked my valves again last night before I fired it up, they were good. So, I fired it up and let it run for about 10 min. Now my next question is, how long should I expect it to blow white smoke before I start to tear into the motor? Since it's been sitting for 3 years I expect smoke and smells from crap burning off and seals coming back to life. If this were a car, I'd say the valve guides and guide seals were gone. Do these have guide seals? It's smoking pretty good.

The fuel pump relay is there, I didn't get a chance to test it b/c it's so freaking hot being in the garage for only an hour an I'm soaked with sweat.

 

[Helmut]

If this were a car, I'd say the valve guides and guide seals were gone. Do these have guide seals?

Yes, they do.