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Post by hemi on Dec 21, 2017 13:39:51 GMT -6
I’m still trying to get this used engine running. I’m convinced it’s a timing issue. They guy I bought it from seemed honest. Said the only problem it had was that it burned some oil in the left cylinder. He suspected it was a valve stem seal. I’m pretty good at detecting BS but of course never 100%. At this point I still believe him. I’m wondering if it’s possible for a timing chain to slip on this engine. The only thing it does is backfire and cough. But usually when I use starting fluid and rarely when just choking the engine. Has anyone heard of it a slipped timing chain ever happening? I’ve been through everything several times over. I’m about to take the valve cover off again and have a look at the chain. The engine did roll over on the way home with it. Just a few seconds after I told my sister not to make any sudden stops, she almost ran a stop sign in the unfamiliar neighborhood. I’m pretty sure it rolled completely over in the back of her van. Amazingly it didn’t spill oil all over her interior. But I had it wrapped up pretty good.
on a side note I’ve decided to dive into my original engine now. I was going to wait until I got the used engine running and then rebuild the original but I might as well start now. Probably could have had it done by now as far as time is concerned.
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Post by eaglerider on Dec 21, 2017 14:46:25 GMT -6
Timing chain cannot "slip". Only way it cant get "out of time" is if someone pulled the cams, and did not set the timing right, when they put the cams back in. ....have you checked the valve adjustment? Do I remember you saying it is an EX500 engine? The 500 will not run in the 454 chassis/454 wiring harness, with out swapping in the 454 flywheel and stator & housing.
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Post by hemi on Dec 22, 2017 13:30:44 GMT -6
Oh, believe me, I’ve tweeked the valves at least 3 times. They are perfect. The 500 I mention earlier was the engine that was used to replace this one. So the 500 is in his bike. All the timing parts are from my engine. Flywheel/rotor, cover with pickups so the only thing that could be a problem as far as those parts go is if the crankshaft is keyed in a different position. I find that hard to believe. As far as I know all these en450 engines are the same.
on the other side, I started to tear into my original engine and found some grooves cut into the valve cover by the timing chain. After pulling the tensioner out I was able to pull the chain up a little bit and saw that a link in the chain was broken. Just one in the stack of links 5 or 6 deep. May be more like that hidden, but this little piece of medal was definitely the one that cut the deepest groove. I was hoping for a simple problem that would fix easy and I could concentrate my energies and funds to a nice rebuild and have a new motor.
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Post by hemi on Dec 22, 2017 13:38:00 GMT -6
I’m still trying a few things before I take the valve cover off again and check the position of he cams. Sometimes I just get this feeling that if I could just get the engine to spin fast enough and long enough it would start. I don’t know why. Perhaps just old experience. I do recall a few years ago it wouldn’t start after some work, but after cranking for a while it started to fire, and I just kept working at it and if finally took off. After that it started at a tap of the button from then on. Same thing with my old John Deere tractor. It was started by cranking a flywheel but if it sat for a while, I needed to pull it with the van and pop the clutch to get that first start. Then it was no problem starting it with the flywheel.
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Post by hemi on Dec 22, 2017 21:15:09 GMT -6
I took the cams out and the chain guides and tension guide. They are chewed to pieces. I bet all that ground up plastic clogged up my oil pump pickup screen or something. Explaining the loss oil pressure. The cam bearing caps are in ok condition. The to nearest the timing chain have some scratches but not deap. I think they will be ok. My micrometer is too small to measure my lobes. My calipers say they are in spec, but I don’t know how accurate they are compared to micrometers.
tomorrow I hope to draw a conclusion about the used engine. Perhaps it will be a parts donor.
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Post by eaglerider on Dec 23, 2017 9:08:57 GMT -6
Better pull the oil pan and check the oil pick-up....bet the screen is clogged.
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Post by hemi on Dec 29, 2017 17:11:19 GMT -6
Yeah, I’m sure it is clogged. I plan to tear this thing apart and make sure all oil passages are clean and clear and to all the measurements for wear before I put it together. I think since it would run for a short while and then start to loose oil pressure it sucked material up until it was clogged, and then it would settle again after cooling down. And do it again. It took me for trips and an entire day to get it the few miles to my brothers house. I would run it until I noticed the oil light flash and kill the engine. Let it sit a couple hours and do it again until I got to the house.
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Post by nateshelton on Mar 11, 2021 16:06:03 GMT -6
Did you figure out what the problem was? My bike is doing the same thing.
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