Idiot Wanting To Do General Engine Rebuild

[d1admiral]

83 ATC 185s. I have the Clymer and am slowly getting all the tools that are required. What preventative maint should be done while I have the engine out? Seals, valves, gaskets? I just don't know, but would like to do it myself as a project. The real question I need answering is how do I tell if I need to bore out the cylinder or just put new rings in? Is it just a visual thing like obvious scratches and what not, or do I need to measure something? What do I measure with? Like I said earlier, I don't know much about what I'm going to embark on, but it should be fun. Any advise you good people can dish out is greatly appreciated.

[brokdown]

The best thing to do with a cylinder, unless you've got a micrometer, and experience, is to just take it to a local shop and let someone there take a look at it for you. They can easily tell you if it needs to be bored. And if it does, you'll need to have them mic it for you anyways in order to know what size piston you'll need. They usually won't charge you anything to check it out and mic it.

[Trikeaholic]

they ALL need to be bored. its only 30 bucks, but then there is the piston. Just make sure the cam chain does NOT fall into the engine. Follow the manual exactly to set the timing properly, and it should run like new. tourque specs are pretty important. too loose, you will leak either oil or compression, too tight, and you will be trying to get a broken stud or bolt out. NOT FUN. Even the head bolts or nuts are only 18-22 FT-LBs. Get a small tourque wrench, dial type 1/4 drive would do any bike motor. My 3/8 is just too darn big for those small fasteners. I gotta spring for a good 1/4 drive one.

[brokdown]

sorry for the mis-info. :oops: ;)
should question my intelligence more often

[KLT Man]

1. Take it to a shop and have them look at it and mic it.
2. Find out how much bigger it is than original, and how much bore is required to make it new. If it is within specs, just hone it and install some new rings.
3. Before boring the cylinder, locate the smallest oversize piston available that will fit you cylinder. For example, if the cylinder requires only a .20mm bore and you can get a .25 mm oversize piston, go that route. Don't bore it to the max, because that will be the last time you bore it. Keeping the oversize bore size to a minimum will extend the cylinder life if you ever have to re-bore it.

Now, if you have torn down your engine, I would recommend new valve seals. They are easily changed. Of course a new gasket kit.

You can also check your valve seats and re-lap them if needed.


JUst my nickel and dime...................................

You dont NEED to have it bored out, most honda's dont need it any way(I know, I've rebuilt half a dozen 185's and 200's) if it's really bad then yes have it bored, but if it's not to bad just have them hone it, it's far less expensive(like $10) and you dont need to buy a new piston also, replace the cam chain tensioners and cam chain(cam chain is like $25, tensioners are like $15) replace rings(around $20 for RIK rings) lap the valves or just replace them also(about 15$ per valve) a good way to test to see if valves are good is to spray some WD-40D into the intake and exhaust, let it sit for 5 minutes and if the valves leak then it needs valves. Honda's are very easy to rebuild.

[d1admiral]

Can't thank you enough. I will take it to the shop and have it looked at and go from there. Appreciate all your help. The torque wrench I need to get. I do not have an id micrometer either, just an od. I think the shop will be a big help. I dont have the engine out yet. Should I take it out before bringing it to the shop or leave it in? The engine runs now, but it has a knock in in it somewhere. That's the whole reason for the rebuild. Can the shop do the inspection with the engine in or will they be charging me labor for tearing it down? I'll call them and ask as well. Again thanks for the help!

[MountainRider]

Before you take the motor off, or tear into it, try adjusting the tension on your timing chain (good directions in the manual, and only takes a minute). If it's got a lot of slop in it, it'll sound just like the begining of a light rod knock or piston slap. If that gets rid of the noise and it's not smoking and has good compression, there's no reason to tear it down.

[d1admiral]

Thanks for the tip. I'll do that tonite. Do I need a timing light for that or any special tools? I'll repost and let everyone know if it worked.

[ATCs Reborn]

if it sounds more like a tap than a knock, might wanna adjust your valves too. actually they're probably ready for an adjustment one way or the other.
exhaust all possibilities before rippin into it. may save yourself alot of time and money.
good luck

[MountainRider]

No special tools required, just an open end wrench. Start it, let it warm up good, and make the adjustment while it's running. If I remember right, the manual takes you through the process step by step for the 200s, but the 185s works the same way.