Changing Piston Rings

[MudBug]

Ive diagnosed my big red with worn rings and valve seals. This seems like a fairly easy job, and I already know how to do valve timing. Is there anything else I should watch out for? Which hone should I buy, flexhone, or other ?

[WilliamJ]

Not tried the flex hone - i've always used stones but either way, when you have finished honing in the 30 degree criss cross pattern you need to clean the bore out until you cannot get any specks of dirt when you wipe with a white paper towel. All the microscopic particles need to be washed right out.

Check the ring gaps by putting them in the bore and ring groove clearances on the piston. See manual for these gaps etc.

Use a proper ring spreader if you can (you can do it with your fingers but keep the ring shape flat - don't wind the top 2 new rings down on to the piston -it's unlikely they'll break unless you force them but they can take a slight 'set' and they won't seal so well. (This doesn't apply to the steel 3-part oil control ring).

If you put a score mark on the piston sand it very lightly with 240 grit paper remove any burrs in same direction as machining marks - side to side (and clean until spotless).

Use lots of oil to fit the cylinder on the piston and be gentle.

[Erics350x]

I wouldn't waste my time just re-ringing it. Every Honda i ever tried that on smoked after a few rides. It'll last alot longer if you bore it and put in a piston kit.

[code200k]

^^X2 since your already there i would do a piston kit and bore it over.

[MudBug]

I have no way to bore my cylinder. No shops around here do it, and If I did find one it would cost an arm and 2 legs

[2hundredx]

i had one that smoked. I honed a good, stock cylinder and bought new piston and rings and put her back together. Alot of compression and didnt smoke one bit. Had it for another year then sold it, still with great compression and no smoke. Id say do what i did.

[Mr_RPM]

i have sent a cylinder out to be bored. just send the cylinder and the new piston. cost me 50 bucks for the guy to go 4mm over on my 110, which is a hard job. most aren't nearly as hard. even if you sent it out to a big shop out in cali or michigan thats only gonna be 10-20 bucks in shipping.

[MudBug]

hmm that sounds like a good plan. I was thinking of using a more aggressive cam as well.

[Dirtcrasher]

^ Your in Canada so shipping isn't cheap........

Whats important is how worn the cylinder is. The guys that rings don't work for are guys that NEEDED to be bored, but that is not always the case. It has to be measured at numerous points (front to back wear more) and I'm sure a machine shop can do that for you. Just give them puppy dog eyes :lol:

The ball hone is great for 2 strokes because of the chambers. Not needed for a thumper, they're just like a small block and a 3 stone auto hone is fine.

I find a drill on low at a slow speed pulled/pushed in and out quickly gives you the cross hatch or aforementioned "30 degrees". If ANYONE tries it in a drill press or a drill on high, it will not work and the rings won't seal.......... And I've seen people do it that way!!

[MudBug]

I dont even think theres a reputable machine shop in my entire province :lol: This engine is very high mileage and I'm surprised it still runs actually. I has been ridden everyday that we owned it ( 11 years) and we were the 4th owners. I only realized that its tired when I bought my other big red, which has a very strong motor.

I am going to look around for a shop to do it, but I don't trust just anyone with my stuff. This needs to be done right because this bike is 90% of my transportation.

It still has decent compression, so i'm guessing it only needs to be bored one size up just to clean it up, right?

[jeswinehart]

Mudbug, just send the jug + piston + rings to Dirtcrasher. If you just ain't got anybody in your province that you feel you can trust, DC is your man.

[MudBug]

send old piston and rings?? for measuring or?? I doubt theres anyone I can trust more than someone here on the boards. Especially DC :D

[jeswinehart]

Yep, send the old piston and rings (and the jug). Reason being is if you can get by with a a light to moderate hone (6 to 8 thousands, and new rings on your old piston that is exactly what DC will do.
No fluff, no bs. He will not try to sell you something you don't need but ain't afraid to tell you like it is either if it do need a bore.

[fabiodriven]

Yep, send the old piston and rings (and the jug). Reason being is if you can get by with a a light to moderate hone (6 to 8 thousands, and new rings on your old piston that is exactly what DC will do.
No fluff, no bs. He will not try to sell you something you don't need but ain't afraid to tell you like it is either if it do need a bore.

It's true. Ain't too many guys around like DC anymore. He's a straight shooter.

[cr480r]

Yep, send the old piston and rings (and the jug). Reason being is if you can get by with a a light to moderate hone (6 to 8 thousands, and new rings on your old piston that is exactly what DC will do.

John .006-.008" is excessively huge clearance...

[Mr_RPM]

^ Your in Canada so shipping isn't cheap........



haha when i typed that i swear i saw Mississippi. lol. my bad...

[MudBug]

Is there any way to calculate shipping from Newfoundland to Massachusetts? I know we have friends in West Brookfield and we mail stuff back and forth all the time