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john deere 318 help, i think the Onan is done for good?

22804 Views 103 Replies 28 Participants Last post by  alfieepstein
New to this forum, and i must say it looks fantastic! lots of helpful people, and lots of great tractor stuff. I bought my "new" 318 in the fall. My first real garden tractor. I searched for quite some time for a machine that could bag vast amounts of leafs, and clear alot of sloped, fairly steep, slippery driveway, and decided on this 318. came with power blower/catcher for leaves and the auger snowblower. It did a great job with the leaves. I was so excited to plow the driveway on this first winter storm in chicago. Well, i tried plowing without the chains, (1st mistake) and the driveway was too slippery, so i went to go get the chains and while doing that, the engine started sounding different, almost like it was on choke. Well, the engine then quit, and now won't start. The starter seems to want to crank it over, but can't so i get a grinding noise. I fear the worst, a siezed engine. There was oil in it, my only concern is that it was parked on a hill for a while, could the oil have drained back leaving no lubrication? is there an oil pump on these Onan engines? I am fairly mechanical, but haven't dealt with tractors too much. Usually if instructed well i can find the problem. my question now is, where do i start? What can i look for to figure out if this engine is done? I'm assuming that since it started ok that it is nothing electrical, and the snow thrower wasn't on and it was in neutral so i don't think its anything related to those two issues. I'm just praying someone with a good knowledge of these machines has seen this before. I don't really want to have to start the post of "so what's the best repower engine" :banghead3 although i'm pretty sure that that is coming.
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Late to the show here but it sounds like your starter bendix might be sticking to me. The bad part is you will have to pull the motor to get to the starter. Not a real hard thing to do but its is what it is. So before you do that make sure all the grounds are clean and tight, check the wires comming out of the key switch for any loose wires, and check the 2 fuses behind the dash also. Good luck and let us know what you find out.......
When you hear the horrible grinding noise while trying to start the engine, do you know if the engine is turning? If not this could be the bendix drive in the starter. I've wrenched on cars, trucks, construction equipment, and riding lawn mowers for years but I have very little experience with my newly acquired 318. Regardless, the troubleshooting techniques don't really change much for most internal combustion engines.

Any luck on determining the fuel delivery issue? My 318 also makes a horrible noise which is most likely the starter that will need attention at some point. After I turn the engine by hand with a wrench on the nut of the front PTO pulley, I seem to get past a potentially bad spot on the flywheel. Other times, the horrible grinding noise results in the engine not turning over. I'm tracing a fuel delivery issue right now. Once you determine if your fuel delivery is okay and you have enough juice to turn the engine over, and eventually get her to fire or run, you should be able to hone in the the grinding noise. In the meantime, you should remain attentive to what the engine noises are telling you. Good luck.
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sorry for the delay, life is gettin busy. Here's the new update. I pulled off the air breather, got to the fuel line going into the carburator. Problem was when i tried to start the battery was dead because i decided to leave the ignition on last time Doh! :banghead3 So I'm waiting for a charged battery, in the mean time i pulled off the rear fender cover. I tried turning the drive shaft at the yoke, but couldn't get it to turn by hand. But considering that its connected to the hydro shouldn't that be real hard to turn anyway? It is in free wheel right now. I had one long hard manual push up a snowy driveway :) When i pulled that gas line i didn't get any fuel coming out, and the fuel filter is empty. So maybe it is a fuel issue? After I get a battery, and check the fuel line, if i get nothing i will try the reserve to see if i can get any fuel coming through that way. If the line is emptied, how long would i have to crank to get fuel going through the entire line again? and someone mentioned that i shouldn't crank over if the cylinders are flooded? if its been sitting this long i dont think that should be an issue. Still should i check for this? if so, how? and is there anything else i should check for before cranking this thing over a bunch of times? I cannot see the cylinder heads through the spark plug holes, there seems to be some type of interior piece that seems to shield the plug. Seem kind of odd to me, but its consistant on both sides so it must be ok. Lucky for me, the guy who sold it to me gave spare parts for virtually every part of the electrical system from an old 318 he had that ironically enough blew a piston, so if its electrical.....there's a good chance i have a spare part :)
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After you start cranking the engine, the gas 'should' start pouring out of the fuel line in a matter of moments.
If you can't turn that driveshaft by hand you have big problems somewhere in the engine, flywheel stuck, or the starter is stuck.
ok, with the battery charged. and now with a great view with the fender cover off, flywheel is turning fine. Drive shaft is turning fine. I could not get a good grip with my hand, but by puttin a screwdriver in the yoke i got it to turn easily. So yay, no engine seizing. Im still getting no fuel from either the reserve or main lines. However, i'm beginning to think its starter related. Based on the noise, the grinding it makes kind of sounds like something is not engaging correctly. could it be that bendix rod you were talking about? The other thing is while watching the starter and turning the key, the starter moves, or jumps, a bit. Could it be moving because something is jamming up? I guess we still can't rule out the battery either. Should i be pulling the starter, and running the starter and battery over to autozone to have them checked? Also, it looks to me like you'd have to pull the engine to get to the starter, that true? If so this baby is getting transported to my dad's heated workshop. The cold snap we just got here makes working in my garage far less enjoyable.
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on the 318 I just purchased the bendix on the started was stuck in the engaged postion, and one of the mounting tabs on the starter was broken. I think maybe this is the case with yours. I cant imagine another reason the starter would move.
sorry, long time no post. Got really busy, but i have now diagnosed one source of the problem. the grinding noise is solved. The gear that comes from the starter is not fully engaging the flywheel. we tried adding washers in between the starter and the engine block to shim it, however, it seems like the starter needs to somehow get closer to the engine. Hard to explain, but its not that the gear isn't coming out far enough, it's that the gear seems to be too far away to grab fully. Like somehow i need to get that starter mounted closer to the block to get that gear in the right place. Any suggestions? my only thought was to shim the outside bolt, that way it would kind of twist the end of the starter in towards the flywheel. But to me, thats seems like im only treating the symptom, and not the actual problem. Any help? On the positive note, im now well experienced at pulling a 318 Onan engine :) And at least i have found one problem. We did one experiment. We had the starter slightly loosened, and my dad wedged a screwdriver in there to keep that starter more towards the engine, and it did eliminate that noise, so we know that was the issue, the bendix gear was slipping on the flywheel. So my ultimate question is why did it start doing that? and how do i get it right? seems to me there is no way to shim that thing left to right, that you can only shim it back and forth on the two bolts that secure it to the block.
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oh, and PS. i did get the starter and battery checked. both passed. though that seems irrelevant now.
Hmmm.....wrong starter perhaps or someone rebuilt a starter with a shorter shaft? What model starter is it?
it is a newer starter, so he might have put on the wrong one. But why did is start ok during the full fall season? also, when i look on ebay, the starters that come up for the 318 onan all look the same. I'm going to attempt to draw the problem in ms paint, so hopefully you can understand better than i can tell it.
got it, look below. what great artwork!
ams
three questions.
is this a REAL onan starter?
the # should be 191-1808-04 or 05
and the tag should say onan and it should have nine teeth.
have you checked the mounting holes in the block,
to make sure they are not, split or damaged in any way?
lastly, was the starter made in xxxxx?
if, so they tend to be JUNK.
shorter, smaller in diameter, and weigh almost two # less.
the last P 220 for 420 J.D. that i rebuilt had a junk one.
it worked fine when the engine was down on compression,
once the engine was rebuilt, it would barely turn it over.
O.K. i,m done venting now.
thank you boomer (the useed onan engine parts guy )
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Is the motor a B43 or P218? I did not see it anywhere.
OK, it has been awhile since this happened to me, but I will try to explain what I came across that caused a starter to have a grinding noise. I had an aftermarket starter in a318 with a B43G that the PO had put on. The nut at the end of the shaft holding the bendix gear had come loose and was about to fall out. I tightened the nut and never had any more problems with it. It was very simple to see once the engine was out.
I don't even believe the original starters have a nut there....can't remember. Unless you just happen to have one of these starters then this post is probably useless...sorry.
I will be headin back over to the folks house tomorrow to try and get some work done on this thing. To answer the few questions since the last post, it is a P218 engine. I can't check the numbers today, but i am almost positive it is a knockoff. however, my issue doesn't seem to be that it doesnt have enough juice, but that its not lining up right, and i had no problems using this machine all fall for leaves. 2nd, why did it decide to do this after the thing conked out. Which seems to most likely be a fuel delivery issue now. Was is just a strange coincidence? Now, i do have what i believe is an onan starter, the guy gave me a bunch of spare parts, however, it is a way different setup than the one on. It doesn't have a bendix rod attached to it, and had a few other differences to it. I know that i would need to buy additional parts to get it on, it appears there would be no way to put it on as is. I will check that nut, but again it appears to need an adjustment to get the gear in the right spot. So let me ask this, could i shim that outside bolt to twist the starter back in towards the engine? the gears wouldn't be perfectly aligned, but they would at least reach each other, or would this type of rig job just land me more problems? I don't want to grind on the teeth of the flywheel anymore, so i can't really address my fuel delivery problem until the starter is fixed.
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2nd, i have questions about the fuel system, so if i do get this starter problem solved i can hopefully start tackling problem #2 right away. How exactly does the fuel delivery work? The best we could tell is that its a vacuum system. Is that true? If so what parts do i have to look at for a blockage, or a break in the vacuum?
You don't want to mess with the starter mounting position because the flywheel may not be cheap to replace. It should work bolted up correctly. My advice, get a new starter.
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