I have my 300 2x4, and today when i was riding it it would run great for about 1-2 min and act like it was lockin up, die and motor would stop that sec. Happened the other day once added some oil to the cylinder and it run like a top, so today after it stoped we pulled it to a friends house added some oil through spark plug hole and started right up, i think maybe my oil injecters bad, so i mixed up a tank of fuel today but my chock broke so when i get that fixed i can tell u more, Good Idea? or not? ditchin the oil jecter a good or bad thing? ifigured then at lest i know shes always being oiled? INfo would be great. Hey elroy hows ur 300 comming? i have seen a 96 400 4x4 in the swap sheet here and thinkin about callin on it. thanks everyone!

 

It sounds like to me that you have a compression or a gas problem. When you add oil in the cylinder that will seal around the rings for a few and raise the compression. Unless you know the compression is good (already tested it) I would check out and make sure you are getting gas; filter, carb, etc. Also check your plug and see what kind of condition it is in. My first thing would be the compression though just to make sure, you would be suprised how a motor will run with bad rings or a cracked piston, etc. Last summer the Piston skirt blew apart on half of my piston. It still cranked, ran, and everything, but one day I was riding it around the yard goofing off and It locked up. I finally got It cranked, reved it, went about 100 ft. and I heard the rest of my piston skirt exiting my exhaust pipe. [img]i/expressions/face-icon-small-smile.gif[/img] I had no idea the piston was in that bad of shape, but had I done a compression check I would have known and saved alot of my time trying to get the thing to run decent, hard to do with a cracked piston.. If your oil pump is bad, you definately have a problem and If you even have a reason to believe it is bad, then you probably already have engine damage.

 

yea i did a compression check on it yesterday, first pull about 90psi but it soon rased over 110psi, i had the head off of it about 3 weeks ago wall looked great yet, i just put new rings in it a while back. i'm thinkin of pullin the head off to check wall again, don;t wanna have to bore .020 over to get the scores outa the wall a 2nd time [img]i/expressions/face-icon-small-smile.gif[/img]

 

Yes, you will not want to have to re-bore if you are already .20 over, because then you would not have a bore left in that sleeve if anything happens later on. Check your compression a few times then try putting a little oil, maybe a teaspoon in there and see if your compression raises. If it does, get new rings. Your compression should be 115 minimum. Good luck.

 

yea its running 90, then works up to 120 fast, 1-2 cranks and its at 120psi, I don;t think the rings r shot if it goes to 120psi in 1-2 cranks are they? i'm thinkin of takin head off and checkin the wall. If the rings r shot y is it keep eating rings? i know the first time i put rings in i didn't get them lined up and they cracked (my Bad) this last time i checked them 2-3 times moving them around and gettin them in the right spot, maybe its cuz i didn't set them right when i put them in? i run a tank through it goin no faster then 1/4-1/3 throttle? thats the way i took it u did it. i've always keep oil filled umm takin pretty good care of it. Just seems odd. Would the piston pin make rings go bad? cuz i replaced the pin when i rebuilt it, maybe it isn't in right, i put it in as the dealer told me and got the snap rings in right place? elroy told me to go through the intake and try to wiggle the piston skirt, i had barly any movment. My cylinder wall had 2 fine (very fine scores in it) from the old rings that were cracked runing up and down as i tryed to figure out what was the matter with it. U can only feel the scores if u have longer finger nails and run all the way around it. Gonna rip the head off it maybe this week and check stuff out! thanks for ur imput. i think i will just mix gas to keep it safe. thanks

 

I am wondering if when you are doing all of this head removing If you are replacing the gasket every time you do it. It is recommended to replace the head gasket when removing the head and not to re-use an old one. Also, you could try a leak down test and make sure you are not leaking anywhere. Was the cylinder honed after you put in new rings? If not your rings will not wear properly without the crosshatch pattern from the honing, that is why you take it easy the first few hours to let the rings seat properly, but without a properly prepared cylinder they will not wear right and you may lose compression. The first few hours are critical and the crosshatch included because after a few hours the crosshatch should be all but gone leaving a good seal with the rings.

 

o ic, yes i have been replacin head gaskets. i didn't the first time but i figured it needed itso i went and got one, ok i understand what u r talkin about the crosshatchin, damn old wheelers, i am lookin at a 96 400 4x4 but i want something newer. I wish i woulda known about the honning befor i put new rings in, my local dealers gota be wondering y i need all the same parts over and over again [img]i/expressions/face-icon-small-tongue.gif[/img] yea the gaskets have a rised ring around them that smashes down as u torque the head down. Would a bottle hone do the trick, then add new rings for the 5th time lol, dealers screwed it up 3 times and i screwed it up once, maybe 2 times, i've been lookin into a snap on bottle hone for a while now, would it be a good idea to get new rings check everything out good and hone it with a bottle hone add new rings and rebrake it in. i don't have a problem with spending time/money on this its what i love to do. thanks

 

Like NC stressed, it's always a great move to hone the cylinder to brake the glaze, and provide a good sealing surface. You can go to your local Sears store and get a ball type hone, not very spendy, but work great. Always use a wet hone...use honing oil. Other light wt oils will do in a pinch. Make sure to thoroughly clean out the cylinder after. Suggested motor rpm (drill with hone) is 300-500rpm, while keeping drill centered over the bore, and rapidily moving up and down the full amount of the cylinder. Go for a little while, then stop to inspect. Just look for a uniform finish, you'll see what we mean about "crosshatch" it's the zig-zag pattern the hone leaves behind. I prefer the bar type hones, these are where you'll either have two or three stones a few inches long. Through other forms of racing, I was always told this leaves a more accurate finish, but they are more difficult to use. Also, are you following a torque sequence when you re-install head/ cylinder. If you don't have a manual (always good to have one) basically you just criss-cross from the fastener you just tightened. Once the machine has been thoroughly warmed up, also go back and re-check those torques.

 

Thanks Ken, sounds great.

 

An added note to Ken's listing. Watch those dang rock hones on the 2-strokers. If you go just a hair to far out the bottom end you have a broken rock.[img]i/expressions/face-icon-small-shocked.gif[/img]