70 atc motor rebuild

[Beau]

So I have to rebuild my son's 70. The motor is apparently trashed according to the guy I took it too. Said the oil was the consistency of mud. Said he was surprised I didn't burn it up and mess up the bearings.
Where can I get a cheap kit to rebuild this thing. Everything I am seeing is cylinder head and piston with gaskets. Do they not need anything else to rebuild?

[tblumer]

Check dratv.com , he has all you need for a rebuild. Hit up Harbor Freight and get a impact screwdriver to get the case screws out. It's the type that you whack with a hammer. I recommend getting Allen head type replacement case screws. Wash all the sludge out and make sure to clean out the oil slinger on the clutch. The bottom ends are pretty bulletproof, just give it a good cleaning and maybe rebuild the clutch.

[Beau]

How long does it take to rebuild one.

[Beau]

Do you have to run race gas with the 88cc kit?

[Daddio]

Do you have to run race gas with the 88cc kit?
No you don't. You may want to check into getting a lifan engine. They sell the smaller ones fairly cheap. I've rebuilt several 70 engines and it isn't that cheap to do right. The Honda 70 engines are great, don't get me wrong, but the for the money I spent rebuilding the last one I could have bought 2 lifan engines.

[oscarmayer]

i like tboltusa.com for a lot of those parts and even some tweak stuff.

have you ever rebuilt one of these motors or any motors before? if not you may want to get someone who knows how to rebuild them to do it for you.
as someone suggested, you could look into one of the china 110cc clones with electric start. they can bolt in with a kit and will run really good.

[Beau]

yes I have rebuilt engines before. one of these, no. I just really want to keep it all Honda. I had 1 when I was a kid and the thing always ran like a top. this is for my 5 y/o son so I don't want to make it fast yet. I just want a very reliable three wheeler for him.
I have seen the complete 88cc kits with cam for like 150.

what else do I need?
I cant seem to find a bottom end kit at all.


i like tboltusa.com for a lot of those parts and even some tweak stuff.

have you ever rebuilt one of these motors or any motors before? if not you may want to get someone who knows how to rebuild them to do it for you.
as someone suggested, you could look into one of the china 110cc clones with electric start. they can bolt in with a kit and will run really good.

[John Tice]

I keep seeing the word CHEAP; how about properly. You want it to last, purchase a manual for the engine. Most everyone has some good advice; it’s time to roll up the sleeves & do a little more learning.
Everything3wheeler was your first best choice

John Tice
503-593-2908 Alternate 541-508-3944
www.smallenginemachineworks.com & www.nwsleeve.com
Turning Custom Cylinder Sleeves Since 1971

[90nut]

Cheap and rebuild don't really go together. As for the bottom end there really isn't a "kit" it's more like crank bearings and some oil seals unless you find other damage.

[Beau]

what should it cost for me to rebuild it. I am not expecting to get out of it for like a 100 bucks. but if these top end kits are complete and all I need is a few bearings and gaskets surely that wont be over 3-4 hundred. may not be cheap but it is cheaper than buying or paying someone 1k to do it.
tbolt has the 108 kit for 550. I would assume that would be a complete kit as it has the crankshaft with it.


Cheap and rebuild don't really go together. As for the bottom end there really isn't a "kit" it's more like crank bearings and some oil seals unless you find other damage.

[1979atc]

Get it apart then see what the cylinder, valves, cam, bearings, seals, and what condition the bottom end is in. If bottom end is good and if the cylinder is not bad get the cylinder honed. And check and see if piston is reusable,Then get new piston rings, valve seals, maybe a cam chain if it's bad and top end gasket kit. Check to see if valves are leaking, if they leak get them lapped in and clean up motor, flush it out good to get other gunk and junk out of it. Then you should be good to go.

[Daddio]

The last one I rebuilt, cost me in the neighborhood of $700. When I say rebuilt, I replaced everything that needed to be replaced. It was done with Honda parts. I work for a Honda dealership and get a very good deal on Honda parts. The only thing I didn't do myself, was install and ream the new valve guides to fit. I rebuilt that engine in 2009. I'm not even sure if you can get all of the stuff I put into that engine anymore. You said that the oil in your engine was the consistency of mud. If that's the case, it will need more than just a little freshening up. But without actually being able to see it and inspect it, I don't know how bad yours really is. You may be able to get away with just putting a 108 kit on it.

[oscarmayer]

call them up. they can help with what you need. Talk to Vince.

[Beau]

where can I buy the engine bearings. apparently all the bearings are bad. I went and picked it up the other day and the guy still had it apart. very few of the bearings moved and some of the ones that did move took a great deal of force for them to move.

I have looked on ebay and a few other places and cant seem to find these things. I have found a rod bearing for a pre 81, which mine is like an 84, and a tranny bearing. is there an all in one kit or do I just have to track them down 1 by one.

[1979atc]

where can I buy the engine bearings. apparently all the bearings are bad. I went and picked it up the other day and the guy still had it apart. very few of the bearings moved and some of the ones that did move took a great deal of force for them to move.

I have looked on ebay and a few other places and cant seem to find these things. I have found a rod bearing for a pre 81, which mine is like an 84, and a tranny bearing. is there an all in one kit or do I just have to track them down 1 by one.

Get all the bearings off that you need and go to a bearing dealer, I have a few around me. They should be able to help you out, and they are a good deal.

[oscarmayer]

you can take measurements of the bearings.
ID
OD
Thickness
then google search for them they may not show up as Honda but make sure you only use Europe or Japanese bearings. do that and your be fine. probably even find them 1/16tht he $ of dealership.