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What should I go from here?

8213 Views 57 Replies 8 Participants Last post by  Helmut
Where should I go from here?

Hey guys,

I bought a 98 300ex off a guy that ran pretty good but it was knocking from the top end like a tink-tink knock didn't bog or anything when I was test driving it. It needed new clutch plates and he had some that came with the quad that were brand new EBC Dirt Racer brand... also had the clutch cover gasket.

Took it out riding that weekend all was great ran fine just the knocking was still going and the clutch needed some new plates but wasn't bad.

So a couple days later I drained the oil changed and took the cover off and found quite a bit of metal shavings down under the oil screen so I checked all the bearings and they were all in good shape and went ahead and changed out the clutch plates and put it all back together and as I was putting the nuetral switch on it sheared off and I had to get it out and get a new one so I finally got it all back together. and it started up and ran good and the clutch was now fixed.

Anyways I took it out riding that weekend and was doing some trails and I pulled in the clutch to check my battery to see if it had fallen out because it's only held in by zip ties and the engine just died on me. So I tried to start it back up again and it wouldn't start... the starter motor was turning but the engine was not.

So I got home and checked all the fuel lines and such and it was all clean no obstructions checked the spark plug and it looked ok nice blue spark... put my fingers over the plug hole and checked the compression and it blew by fingers back so now I'm stuck... Any ideas?
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I am currently replaceing all the gaskets on my quad and fixing what needs to be fixed. I have the right side crank case cover off so I can see all the gears for the timing chain etc. My question is is their a certain way the chain goes on the gear at the bottom in relation to the cam shaft gear? I have a brand new Clymer manul I bought off of e-bay and I can't find anything in it that tells me that their is some marks or what not. Now I found some marks on the tom gear that attaches to to the cam but none on the bottom.
Go to the other side of the motor and take off the two allen wrench covers ones big and the others small. Turn the bolt in the bottom hole and shine a light in the top one and turn it to the second T mark make sure your at top dead with the piston and make sure your on the compression stroke. Then match the marks on the timing chain gear there should be 3 marks one goes up and the other matches up with the top of the motor. If you have any other questions feel free to ask i am currently rebuilding my whole motor so i will be glad to help you out. Oh and welcome to the forums! you will be glad to know that lots of ppl here can help you with any problem you may b having. Welcome to the family!
Okay thanks a whole bunch! This will help me alot. Now I will just have to put it all togeather!
Welcome to the forums!
Yep no problem bro!

So I have it all completely apart and I'm stripping the frame down and repainting it and the rear swing arm/ axle. Also have the motor torn apart and got a new cam chain, cam chain tensioner, cam chain guides and some new valves and am getting them and the head resurfaced/ reseated then once all that is done I'm gonna put it all together and put a new carb rebuild kit on and fixer all up and go from there.

Hopefully it starts... if not it will look good. LOL I went with a flat black and I'm gonna clear coat over that and I'm leaving my nerf bars chrome... so It will look nice. I'll post some pics up soon.
Sweet Sounds Like its gunna look good. I dont really worry about the cosmetics all that much i just like to make mine go fast lol
from what your telling us..sounds like your rings are pretty much can check your cylinder with a mic..or new rings..with new rings..slide them down into the cylinder with the gap facing up.after you get the rings down in the cylinder..turn them like they would be facing as if they were on the piston..check the top...middle..and bottom of the cylinder with the new ring...don't check the cylinder with old will not get a correct reading...with a new ring in the cylinder..either use a fealer gage..or do like i do..i go by sight..hold the cylinder up to a good light source..if you can see light through the cylinder with the new rings..the cylinder will either need a boring..and if not too bad out of may get by with just a honing...depends on how bad the gap is after you get the new ring in the cylinder ? for the knocking noise..could be a piston skirt hitting the crank..but.if that was the case..your piston skirt would be probally broken off by now. after you get your timming chain in..and timming chain guides..ligthly oil your cylinder..put your base gasket on..then cylinder..make sure the gaps on your new rings are not all lined set the gaps..and don't line the gaps up with either the intake..or ex or the piston wrist you go to push the cylinder back down on the lower end..first..tie a peice of wire to your timming chain...long enough to reach all the way out of the top of the motor..and easy enough where you can reach the end to untie it...lay 2 pieces of 1/2 x 1/2 x 6 '' of wood across the base in between the studs..put your wire through the cylinder..ease the cylinder down..carefully starting the rings in..after your wire is through..tie it off..finish getting the piston inside the cylinder..remove the wood after the piston is in..lower the cylinder all the way down....install the timming chain guide..untie the it through the head gasket..then tie the wire back off...get your cylinder head..untie the the wire through the head...set the head down on the clylinder..tie the wire back off...lay your cam down in the head..face the cam lobes down..with the piston on tdc < top dead center > can remove the inspection cover's..< they are round with a screwdriver slot..or allen bolt > one is larger than the other..with a socket..i think it's 17mm..while turing the flywheel around..look in the smaller for the T to come around..line it up with the mark on the hole..might be a single line..or an arrow..while your turning the flywheel..make sure there is enough slack for your timming chain to rotate...after you get the T mark to line up..and your cam lobes facing down..lay the cam sprocket on the end of the cam with the chain already on the cam sprocket..don't worry about the slack for now...on the cam should see either a punch mark..or maybe double lines ?..not sure on this part for your bike..if it's lines..while your putting the cam sprocket on the end of the cam to bolt up..face the lines horizonal to the head....the lines will be side to side..and the cam lobes will be facing down..keep an eye on the T mark on your flywheel..< incase it moved on you >..the piston HAS TO BE ON TDC !..once you get all that on..and lined up..bolt the head everything bolted down..loosen your rocker arms..set the gab...not sure what yours calls for ?..tighten the valves down..install your valve covers..with the key on..kill switch OFF, and oil line not hooked up..crank it a few should see oil comming from the line ?..if not..means your gonna have to replace the oil pump...if you do get oil..bolt your oil line up..spark plug back in..key on..kill switch on the RUN position..crank it up..see how it does..good luck.
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How can I tell if I have 400ex A arms or 300ex? My A arm grease boots are shot and apparently there's not a replacement just for the boots.

So I'm gonna have to replace the whole A arm I don't know the difference between 300ex and 400ex A arms. Anyone?
they both fit a 300
Please read the question b4 replying... I'm asking what the difference is between them. Anyone else?
The 400ex ones are a +2 wider if you have stock rims on the front. I have douglas rims with a 0 offset and they are like a +1 1/2 or so. And if you buy the kit from diamond j customs you can put 400ex shocks on and get way better suspension travel. When you put the 400ex a-arms on with the 300ex shocks its like a lowering kit for the front which is kinda gay. And you literaly have no suspension at all. That should clear things up for yah bro!
OK Thanks! That helped. I think I still have 300ex A Arms. Are those kits made for Jumping as well and is there one for the rear or do I just need to find a stock '01 predator shock?

I have some extra A arms that came with the purchase of my quad not sure what they are but they also came with some shocks that look like 400ex shocks I'll have to look into it.

Is that worth doing though if the rear of the quad isn't widened?

I'll figure out what those extra parts are and post back here so we can find out what would be the best and cheapest for my situation. I'm fine with stock parts as long as it's cheaper.
BTW here is a teaser.

The frame is just primed this is the second coat. Also the rear swing arm is primed... it's getting there!
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Yes the front +2 makes you handle alot better way harder to flip and you can throw the back end around corners alot more. The ones you have on it look like 300ex ones but its really hard to tell. As for the back shock. They are fine stock if you ask me i mean i jump some pretty gnarly gaps on mine and have never had a problem with it bottoming out in the back. But thats up to you! And yes the kit from diamond j customs is very strong and easily capable of jumping and stuff. I hit a 30 foot double with my quad and its never had a bend or crack in there kit.
All back together!!!

So It's finally all back together but Im unsure of the electrical if I hooked it back up right. Everything is fixed but im not getting any spark at all where as before I took it all apart it was getting a nice blue spark.

I replaced the spark plug cap but no luck... Any ideas? If someone could post pictures of what wire are hooked up where on the shifter side of the 300ex that would help me out alot to see if I got the electrical right. Thanks in advance!
I don't have any pictures, but here's a wiring diagram for the 2001 300EX.

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So I now have spark!!! Yea! I didn't start it yet cuz well it was 3am and I didn't want to wake up the whole neighborhood.

Ended up being the regulator wasn't plug in completely. :unsure:

So I'll update you guys in the morning and Ill have some pics. Night!

Started right up, first try!! It still is knocking though... not sure why. I think it maybe the cam chain but I'm not sure.

I have swimmers ear in both ears, so I don't have very precise hearing at the moment. Valve clearance is set to .004 on all valves so I'm pretty sure it's not that...

Anyways it seems to run good I haven't rode it yet but I have a K&N air filter, DG pipe and a stock main and the pilot 2 1/4 turns out.

Any suggestions before I take it out for a test ride? Is there anything I need to do special because it has two brand new exhaust valves in it?

BTW here are some pics!

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I would double check your cam chain wheel bolts. They backed out on mine the first time i started it after the rebuild. Your probably gunna have to rejet with the filter and pipe. The stock main isnt gunna be right. Your gunna run it lean when you ride so it may seem hotter than normal. Other than that i wish i had the time to pull mine down and pain the frame black! That looks SICK!
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