2003 quadsport z400

[HeWasRidinDirty]

I got this 400, that wouldn't start. It would try, but wouldn't catch. I checked the valves and the L intake was tight at .002. The compression came in around 120. It didn't improve after a couple of drops of oil into the cylinder. So,I figured it was the valve causing the problem. So, I got the valves squared away, but it still won't start. I checked the spark and it seems like it's getting an intermittent spark. It fires a few times then nothing. If l let up on the button and then hit again immediately, it will fire a few more times, then repeat. So, what am I looking at as a possibility? Electrical issues are not my strong point. LOL

[HeWasRidinDirty]

Oh, and also the camshaft timing seems odd to me. I watched a couple of utube vids and both pointed out a "3" on the intake cam sprocket and a "2" on the exhaust sprocket. The one I'm working on has neither. Each sprocket has EX on one side and IN on the other, not directly opposite each other, either. Someone had painted IN/EX on the sprockets and put some white dots on them where they line up with the top of the cylinder head. IDK if these are some aftermarket camshafts or what.

[Frank Angerano]

Could be a bad cdi. 

I would start by testing some of the regular components to see if there within spec.  

Stator, pick up coil, secondary coil and the regulator/rectifier.  If all of that tests fine then all indications will point to a new cdi.   

[HeWasRidinDirty]

Thank you. It seems like the spark is ok with a new plug. But also when I crank it over it struggles when ever it hits the compression stroke. I thought it was a weak battery so I got new larger lawn equipment battery, fully charged, and I hook it up via jumper cables and it does the same thing. You think the starter is bad/weak? It pops and acts like it wants to start, but, it seems if it was spinning faster, it would. I wonder if I could bump start it with a truck or quad? That might answer that question.

[Frank Angerano]

Honestly if that engine is having trouble at the top of the stroke plus the backfire makes me thing the timing jumped a spot.  I would double check before you keep cranking.   

[HeWasRidinDirty]

1 hour ago, Frank Angerano said:

Honestly if that engine is having trouble at the top of the stroke plus the backfire makes me thing the timing jumped a spot.  I would double check before you keep cranking.   

I may have to take a look at that. It did the same before I took it apart and checked the valves. Someone has had it apart before that, tho. Read my 2nd post. It doesn't have marks on the cam sprockets like described in the Y.T vids that I watched. 

[Frank Angerano]

There are marks.  Someplace on there.   Unless the sprocket was put on backwards and your not seeing them.  It’s either a dot or a line. 

[HeWasRidinDirty]

Backwards?? that may be it. These cam sprockets have bolts in them that look out of place. Like someone "made it work" at some point. I'll put some pics up later. On this video there are no bolts on the cam sprockets. Weird

 

[Frank Angerano]

That’s a great video. Sounds like the terminator doing the timing.  

Lol. 

Let me know what you find out. 

[HeWasRidinDirty]

So ,here is the cam sprockets. This is at TDC. I didn't do any of the paint. Notice those bolts? 

The white dots on the cam lobes denote the center of the lobe. I did those. Aren't those supposed to be 180 from each other at TDC? 

 

 

[Frank Angerano]

I would say forget any white marks.  You should have a clear stamped line that’s supposed to be 180 from each other that aligns with the top of the engine head cover. Just like you seen in that video.  And make sure the flywheel is on the T mark on the sight hole. 

[HeWasRidinDirty]

There are no marks on the sprockets other than the IN that you can see at about the 10 o'clock position in the first pic. There is an EX stamped opposite side. Same on both sprockets. You might be onto something about them being on backwards. I'm gonna pull them out.

 

 

[Frank Angerano]

Ok let me know I’m curious.   

[HeWasRidinDirty]

Here's the back. It ain't on backwards

[Frank Angerano]

I’m wondering if there aftermarket cams and sprockets in that engine.   Maybe hot cams? Take a look at this hopefully it helps.  

[HeWasRidinDirty]

Hmmm IDK. If you look at the diagram that you put up, and also on the video, you will notice on the intake cam that the keyway is at about 1 oclock and 11 oclock on the exhaust. Now, look at the first pics I put up before I took it apart. On the intake the key is at about 11 and on the exhaust it's at about 3 oclock. Fuuuuuuuu... something smells here. LOL

[Frank Angerano]

Lol well get after it and make sure timing is properly aligned.  If so great, if not then well hopefully no hits between the piston and valves.   

[HeWasRidinDirty]

I'm going to email hot cams inc. and ask them if these look like  their stuff. These are definitley not OEM camshafts. IDK what else to do. 

[Frank Angerano]

Have you followed the diagram I sent you ?

You can see the position of the cams in that image.  

[HeWasRidinDirty]

2 hours ago, Frank Angerano said:

Have you followed the diagram I sent you ?

You can see the position of the cams in that image.  

Didja look at the pics that I posted? Those 1 2 3 marks aint on there. That's the crux of the matter. 😉

[Frank Angerano]

Yes I got the pics. What I meant to say was have you tried to line up the cam lobes as per the image (also the key ways on cams) I sent and see if the flywheel is near at TDC.   If the cam lobes are no where near the image on the manual then there clearly a problem with timing. 

[HeWasRidinDirty]

12 hours ago, Frank Angerano said:

 

Oh, ya, the lobes. They seem to be in about the same location. If they are aftermarket cams, then, the keyway is probably irrelevant.

Edited August 22, 2019 by HeWasRidinDirty

[HeWasRidinDirty]

I pulled the stator cover and stator off today. It looks like the key on the flywheel is ok. Is there a way to check the timing with a timing light? I really don't know. If it was an old car or truck, then.....LOL. 

I'll post up some pics of what I found inside the stator cover a bit later. 

[Frank Angerano]

Believe it or not you can do that but it has to be a running bike Un fortunately.  I’ve seen and tried after watching.  When the bike is running up to par I’ve seen a person put marks on the flywheel and on the engine casing. After hitting it with the timing light it worked. Crazy stuff but yes.  I have to try to find the video.  It wa s a good idea. 

I honestly think your cams are off, hope I’m wrong. But I think you have to go back and look at what was done and try to locate some information on the cams you have or replace with oem cams and sprockets.   

 

[HeWasRidinDirty]

Heres the pcs that I found around the stator. There's parts of a spring that would be found on an oil/water seal.

The drain plug. 

[Frank Angerano]

Oh boy. Any idea where there from ?

 

So you found them inside the stator cover and also in the oil when you drained ? 

[HeWasRidinDirty]

Yes, exactly. That round pc was stuck on the drain plug. 

What kind of seals are in this engine? It doesn't have crank seals like a 2 stroke does it? Water pump seals come to mind, but, there's no water in the oil or oil inthe water. It hasn't leaked any oil either. 

[Frank Angerano]

I’m thinking possibly a compression relief spring ? Not sure if the engine has that. But based on the short history of the cam replacement and top end work  that would be my guess. 

See that small spring on the cam ? It’s possible that it has come off prior to the last owner rebuilding the top end.    

[HeWasRidinDirty]

Most 4 strokes have a compression releif mechanism on the exhaust cam right? This doesn't have anything on the ex cam. Nothing. It looks exactly the same as the IN cam. ANd if there was a spring on the ex cam, how would it get to the stator? IDK. I'm about to light this thing on fire!  LOL

[Frank Angerano]

Lol take a deep breath and maybe a step back. To much time at it will make you crazy. My feeling is that spring is exactly what I think it is. But I could be wrong.   If it fell down Into the cylinder it could have easily been mangled up in the cam chain into pieces and basically been pumped through the engine.  I’m thinking along these lines like I said earlier based on the top end work.  I would change the oil a few more times with cheap oil to make sure you get it all out.  You can use paint strainers to catch any debris as you drain the oil and re use the oil over to keep flushing the system.   Once it’s all clear put a better grade oil in. 

If it’s just the small spring chances are it’s not going to do much.   Go through all the gears to make sure it’s shifting, you can do that just by rocking the bike back and forth and go through the gears.  

Stick with the timing to make sure it’s correct  and get it fired and listen to it run. Take it from there.   That pic I sent you is a cam  that’s for your machine.  

The only other option is to pull the engine off the frame and set it on a bench and tare it down.   Not sure how far you want to go but it is what it is. 

Lastly is the previous owner: did he or she give you any background on this machine ? It seems like you don’t have much background history with it as to what was done etc?