Junkyard 185S motor tear down

[BarnBoy]

Picked up this 185S motor at a junkyard 3 weeks ago for $15. Cases are decent, doesent look like its been thrown around. But, it wouldnt turn over past a certain point. I bought it to tear down and learn the inside of a Honda ATC engine before I rebuild my good 200M engine. This is an experiment and I dont really care what happens to it, so great for learning on. Figured I would also make a post with a couple pics in case anyone wants to tear down a similar engine.



Camshaft looks really good.


Notice pieces of spring on the magnetic pickup.


No springs, wonder where they went......


AHHHHHHHH!! I think that is why its not turning.


I think the cylinder will be usable again on some other bike, but would very likely need to be bored out. At least thats my guess. There isnt much pitting though.




Hmm, yeah I dont think this motor will run again.......




So, if you are ever thinking about leaving a engine outside with out a spark plug....dont do it! It makes a mess. I can hear water sloshing in the bottom of this thing. lol Rod bearing is seized up, crank bearings have rust, dont want to turn very easily. And I had to beat on the piston with a piece of wood to get it to slide out.

I think the piston could be cleaned up with a wire wheel and used, and I think the head would be usable again too if gone through.

Thats as far as I got today, and I did learn some useful things regarding tearing these down, so I am happy. Its helps to follow a manual and its really a very straight forward and simple job. Hoping to eventually split the cases and tear this thing down to the last bolt. Will try to post pics as I go.

[DAM shop]

Good way to learn BarnBoy and I like the fact that you used a manual.

[ironchop]

Great post.

The head and cam looks to be still usable and will interchange with your 200M topend if needed. The jug appears to be usable (after a bore job) ....both are worth well over $15 and I'm sure there are a few other salvageable parts in there too.

You still came out ahead

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[125Mmadness]

You might want to measure that cam and see if it's high performance, someone's been in that engine before, it has a high comp piston.

[BarnBoy]

Thanks guys, its always nice to have spare parts too. I actually have a good looking bottom end sitting in the shed. Hmmmm.... Gotta see what the cases are like on it, might be able to frankenstein something together.

You might want to measure that cam and see if it's high performance, someone's been in that engine before, it has a high comp piston.

VERY interesting!!! I thought the piston looked a bit different, but didnt think too much of it. Could it be a Wiseco piston??? I got clean it up and see if there are any numbers on it....any maybe measure it too.

Do I just measure across the lobes on the cam? Like from the tip of the lobe to the base of the lobe?

[DAM shop]

Thanks guys, its always nice to have spare parts too. I actually have a good looking bottom end sitting in the shed. Hmmmm.... Gotta see what the cases are like on it, might be able to frankenstein something together.



VERY interesting!!! I thought the piston looked a bit different, but didnt think too much of it. Could it be a Wiseco piston??? I got clean it up and see if there are any numbers on it....any maybe measure it too.

Do I just measure across the lobes on the cam? Like from the tip of the lobe to the base of the lobe?

yes that's what you measure that would be your lift, measuring the width would be your duration. The lift will tell you if its stock or not.

[125Mmadness]

Could it be a Wiseco piston???

Wiseco, BAPP, Helm and son, etc hard to tell by just the top.

[ps2fixer]

Nice to see you got it, and got it cheaper than the price stated before, have to love bargaining.

I know you're not putting that engine back together (we think atleast), but those springs that rusted apart you can get from Honda yet. I sell them in the 3ww shop for the ease of finding them, but I list the part number if you want to order direct from Honda. The rest of the unit looks usable, just needs to be cleaned up and lubed, I've seen worse on running engines.

Besides the tear down, don't forget to test electrical parts too, since you have a manual it should be easy as long as you have a multi meter.

You could try the hone the cyl (tool is fairly cheap), but I suspect there will be pitting. My dad uses a special tool that's for shaving down surfaces for old school bearings, like 50's era tractors used. He uses it to clean up the bore on rusty cyls to see if they are savable as is or need more major work. Not sure what it's called though, it's a triangle shaped tool with a tapered tip and it must be hardened steel or something, I've never seen him need to sharpen it.

[BarnBoy]

Thanks ps2fixer, I picked up this motor and an old Lawn Boy push mower for $30 total. He gave me $5 off cause I brought it an old aluminum radiator and a few other assorted aluminum scrap. I dont think its going to go back together. Not to run at least, because the rod bearing is rusted and seized. I can hear water sloshing in the bottom end which sucks, but thats to be expected after sitting in the elements for a while I guess.

Thanks for the info on the springs, if for whatever reason I end up needing them I will swing by the 3WW shop and check em out.

Will check out the electrical stuff too for sure. I do have a multi meter and a little experience with ATC electronics. Kinda stinks it would need a bore cause this piston is the standard size.

There are the numbers 156 and then a little "W" mark on the bottom of the piston so I am assuming its a Wiseco?? Attached a pic of the top, will try and get pics of the bottom as well. How can I tell if its a 10.25:1 or?? Looks to be very usable. Any idea on value?

I measure the cam, looks like the lobe on the clutch side is 33.5 mm and on the flywheel side 33.9 mm. Is this a high performance/larger than stock cam? Will try and get a pic of it too later.

[125Mmadness]

Definetely a Wiseco piston, STD therefore 65mm as that is the smallest they make. The 185 engines have a 63mm bore so that one is 2mm over. Just measured my stock atc200s cam 31.2mm flywheel side (intake) and 30.9mm exhaust so you have a higher lift cam, good score! I wish I could remember the measurment that I got on my cam in my 200s, it had much higher lift than stock. It came with the 200x head I bought when I did my most recent rebuild.

[ps2fixer]

Wouldn't the stock 200x cam have higher lift since it's a higher performance built 200 series engine? It has quite a lot more compression ratio than the 200S engine and I assume the 185S.

If the cyl isn't savable, but you want to reuse the piston, I could probably dig up a 200 series cyl for fairly cheap, or just watch ebay.

Actually, just looked up the bore size on a 200E and it's 65mm, so maybe it already has a 200 series cyl. So I guess really you picked up a 200cc engine. I'm not sure how to tell the 185 vs 200 engine apart besides the cc size on the cylinder. FYI, I used the 200E service manual since I don't have a proper Honda Service manual for the 185/200s engines.

[125Mmadness]

200x cam is hardly anymore lift than other 200/185 engines. Any 200 cylinder (except xr200 which is 65.5) is 65mm std. 185 is 63mm std.

[BarnBoy]

Wow, I am glad I picked this thing up. Its got some cool performance parts on it that I would not have even thought to look for.

It says 180 cm on the cyl so I know its a 185s or was. But yeah technically its a 200cc now I guess. I think serial number below the sprocket might tell too. Will have to look.