piston honing

Thanks for the ideas and info so far guys! Here is my update for now:

Tonight after work I continued mostly with general cleaning. This 29 year old engine is just plain dirty. I tore into the head as well, and took the valves out so i am ready to give them some attention in the near future (planning on lapping them). Unless I find something else that i have to do tomorrow night, i will start measuring and checking parts to see if they can be reused. The bike as 17,000 miles on it, and besides being dirty everything looks good to the naked eye. I'm on a college budget and so i'm really hoping to not have to stick to much more money into this bike. I just want a reliable commuter out of it (not to mention a do-it-myself mechanics lesson). So it is a fine line for me in deciding how to keep the costs down while still doing the job right. Anyway back to the measuring... I suppose I will have to pick up a vernier caliper of sorts in order to measure the cylinders, unless measuring the gap of a ring would do??? I've got a micrometer, but that will only measure thicknesses, not spans. Also what is the best way to measure the chains? As far as sealant goes for the case, would I be able to use "Seal-All" adhesive? It says it is gas and oil resistant and worked ok for me to seal intake manifolds in an earlier attempt to get the motor going.

So I guess that is all for now as i need to get some sleep. I will get some measurements soon and then maybe see what the general consensus is as far as the honing/new rings situation goes.

Thanks guys!

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Dave
New London, Wisconsin

If you measure the valve height before and after the lap job, you can estimate the valve shim required.

A good sealler you can buy anywhere is the permatex Ultra Grey silicone. There are more bad sealers, than better sealers compared to the ultra grey.

Also for the very reason Wierdgeorge mentions in the sealers Thread. I prefer only OEM gaskets. But I haven't tried to buy any in a long time.

For measuring tools, I recommend you pick up a digital caliper and tee-bore gauge set. You can find both for a reasonable price. The tee bore gauges are spring loaded and the arms on the tee pop out to fill the bore and then lock. You pull the guage out of the bore and measure the distance between the extended arms. They usually come in a set so as to be able to measure a variety of bore diameters. Get a decent digital caliper. At wider diameters a cheaper guage may be misleading and will only save you a couple bucks over a better gauge. If your desire is to learn some mechanic tradecraft, then some decent measuring tools should be one of your first purchases as NO mechanic can be without them as they are the bread and butter that allow a mechanic to make reasonable decisions as far as rebuilding goes. If you are on a budget, here is what I would do:

1. measure piston/bore clearance; to save money, you could take the block and pistons to a machine shop
2. clean up valves with wire brush, lap them in and replace valve seals.
3. replace cam chain WITHOUT splitting cases by using a master-link type chain which will allow you to avoid buying a full gasket set
4. if you find your piston/bore clearance is outside spec, buy a new block/piston set off eBay
5. re-ring regardless... hone cylinder bores

With the valves cleaned up and lapped in and new seals, new rings in bores that are within clearance and a new cam chain, you will get many miles out of the bike before it needs attention. Putting the 17K mile pistons/rings back into the bike with no attention is going to guarantee that the bike WILL need attention in the future. Read the thread on sealants and notice there is no concensus on what to use. I suspect most of the OEM sealers are made by Threebond and would recommend the appropriate Threebond or OEM type sealer. I use Hondabond stuff as that is what the multibrand dealer in San Antonio carries mostly rather than Yamabond or Kawi-bond or the Suzuki stuff. Hondabond HT is the same as Threebond 1203 and the other Hondabond is the same as the 1107.

Update for the night:

Well I took a trip to walmart and an auto parts store and came home with some loctite, some more carb cleaner, some "Permatex High-Temp Red RVT Silicone Gasket Maker," and a nice digital caliper. I went at measuring and my Cylinder bore is well within the wear limit, as is the piston diameter and Piston/Cylinder clearance. Now as far as ring gap goes... The two compression rings on all cylinders are within the specified range, but close to the worn end. However, the listed "wear limit" is 0.0275", well outside of the specified range of 0.006"-0.012". Would that mean that i would still have room to wear if, say, i honed the cylinders and put the same rings back in? Sorry if I am frustrating anyone as i know that i really should replace the rings but I am pretty broke for the time being. I also cant find rings under $56 a hole (the $56 is at Bikebandit.com. I checked Z1 Enterprises and there aren't even rings listed for my bike). My oil rings are actually quite a bit out of the wear limit as far as gap goes, however they are not quite as important as compression rings are, correct? Anyway I guess I would definately spend $80 dollars on rings, like told about in a previous post, if i could find them.

Also, to clear up some info. I do have a complete gasket kit allready...i just need the sealant for the case as there is no gasket made for it.

Thats all for now.

cool,i think everybody should be required to build a low budget motor once in a while just to remember how much fun it is to scrounge for parts! :pinch:

Why don't you just stick it back together with the current rings/etc, buy another motor when you can afford to spend $100-$200, then take your time to rebuild the second one?

In the meantime, if the bike smokes a little, who cares, you will be building the replacement motor and doing it right.

You might get lucky and find a good motor for that price that don't need rebuilt, then you can put it in the bike and build your current motor as time and money becomes available.

wireman wrote:

cool,i think everybody should be required to build a low budget motor once in a while just to remember how much fun it is to scrounge for parts! :pinch:

Describes me to a "T", the only parts I buy retail are wear items like tires/batteries/chains and sprockets, everything else is used or eBay finds

steell wrote:

wireman wrote:

cool,i think everybody should be required to build a low budget motor once in a while just to remember how much fun it is to scrounge for parts! :pinch:

Describes me to a "T", the only parts I buy retail are wear items like tires/batteries/chains and sprockets, everything else is used or eBay finds

got any rings for a 31 ford 4 cyl flathead? i threw this one back together in early 80s since i didnt have money to finish:P

Post edited by: wireman, at: 2007/06/06 00:07

Be careful when installing the rings, if you accidentally bend an oil ring, you will have a smoker.

I recomended the Ultra because it is resitant to oil and gasoline, yours is not. And you don't need any high temp silicone for anything you are doing anyway.

The only thing it will do, is tell everybody that sees it, that you did it yourself.

Post edited by: Capt. Quirk, at: 2007/06/06 02:25

I am curious... how did you measure the cylinder bores using a digital caliper? You have to make six different measurements... at different depths and different angles to determine if the bores are out of round. Tee bore gauges are the only way I know to make this measurement. Anyway, good luck.

Well, I think I've kind of decided what I'm going to do. I did only measure the piston diameter right up at the top with the digital caliper and there it was ok. I guess i understand that it really should be measured with a T-bore gauge, but frankly, if they are out of round I don't know how much farther i am willing to go to make it perfect. I think i am just going to hope for the best -- sorry to any perfectionist out there... i wish i could make it perfect too. I have decided to get new rings. I found some at a local shop for 120ish dollars for the whole set. I got a little loan from my mom and hopefully this way i can do things right. I'll probably return the red high temp permatex i got at walmart and take a trip to somewhere where i can get the ultra grey. I still need to buy engine bolts, as i used easy outs on quite a few. I kind of want to get blinkers, too, instead of putting back on the ugly fairing and saddle bags that came with the bike. Add spark plugs, valve shims, and oil to that and I hope I can afford everything. But I think that I now have enough info and direction to hopefully pull this off. Thanks for the help guys and wish me luck for now. Let me know if you have any other ideas. I will probably have a post in the carburetor thread soon. I don't know a whole lot about them. Thats all for tonight.

youll get there,it all takes time!