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 Break In 
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Joined: Fri Jan 18, 2013 9:25 pm
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Location: Greenwood, Nova Scotia
Post Break In
Thought this might be useful to some and perhaps drum up some good info on this topic.


+1 Ja-Moo

G Bells 2 stroke tuning book says this about rings..

"The cross-hatch pattern the hone leaves on the cylinder walls is critical if the rings are to bed-in quickly and last for a long life. Personally , I prefer a 45° Crosshatch with a finish of 10-12 microinches. This type of finish makes it necessary to run the rings in, but they will wear well and not leak.

An engine that has been properly prepared can be run-in in about 45-60 minutes. Start running at reasonably low speeds with a rich mixture and additional oil in the fuel. If you normally use a 20:1 mix, run-in on an 18:1 ratio. After about 15 minutes of operation at a fairly constant speed, try varying your speed and occasionally use up to about 3/4 throttle. Continue changing your speed for another 15 minutes, but take care not to accelerate too briskly. Prolonged operation of a two-stroke at part throttle followed by a burst of full throttle may damage the engine. This occurs because only a
small amount of oil is present in the engine during constant light throttle running. Suddenly opening the throttle severely loads the engine but only a small quantity of oil is available to lubricate at slow speeds.
During the next 15 minutes gradually build up to racing speed, but do not use full throttle for more than two hundred yards on the main straight. Accelerate hard out of the corners for the last 15 minute segment, easing off after each burst to allow the rings and piston time to cool before the next blast. The hard acceleration is necessary to bed the rings into the bore. Do not hold full throttle for more than a few seconds or the
rings and bore could overheat and glaze. Some engines begin to 'lock up' during the run-in period and then seize under
actual race conditions. As a safeguard against this, I would recommend that you remove the barrel after running-in and examine the piston for any sign of scuffing. If you find any high spots on the piston, remove it from the engine and, using a smooth cut millsaw file, gently file the high spots off the piston. This does not sound very
scientific, but I can assure you that it works."


I tend to believe in
Making sure your timing is correct, jetting is close not to fat not to lean..
20:1 Bean oil [Castor based]
#1 Warm up - idle, blip throttle a little - until cylinders are worm
#2 Let cool -check head torque
#3 Start -Idle till warm, ride at varied throttle- 5 minutes.
#4 park let cool down -re-check torque
#5 Start let warm blip-ping throttle up to 5k rpm
#6 Ride harder up to 7k -2 minutes varying throttle
#7 Let cool
#8 ride it like you own it.. [burn out 1 gallon of 20:1 fuel]
#9 Let cool - fill tank with mix ratio you intend to use [32:1 most common]
It is ready to ride..

_________________
2005 Yamaha BW's Orange with Flames
Top Performance Trophy 70cc BBK
Stock Carb 46 Pilot 84 Main Needle Raised 1 notch
Leo Vince TT Exhaust
Carbon fiber reeds
Stock Airbox Snorkel Removed
Malossi Variator 7g weights
Malossi Delta Clutch, Yellow Contra, Yellow Springs, Pivot plates closest to pivot (Hardest setting), Winged Bell
Stage 6 14/42 Upgears
Dual Headlight Mod
Orange Trail Tech Tach/Hourmeter
Vented Trans Case
Shaved tail
Rear Turn signals relocated to brake light assembly, flush mount front signals
Tun'R carbon fiber mirrors


Thu May 23, 2013 8:09 am
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Post Re: Break In
I did find this post interesting.

When I was out riding my new kit I notice that when I close in on 60mph, I hear a lot of wild noises that say let off. My last kit did this during the break in also, but as time went on it sounded more and more solid as I approached top speed. I currently have like 30 miles on mine, and I did a very similar break in to the one described above. Checked my head torque, and they were all dead on even after four or five short rides. I cannot find any better break in steps than the one posted above though, so I would assume this is a good it of info. Thanks grav, and I hope all is well with your new setup

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MurderZuma-Sold


Thu May 23, 2013 9:30 am
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Scooterologist

Joined: Sat Oct 18, 2014 3:56 pm
Posts: 86
Location: Simpsonville
Post Re: Break In
I have taken a picture of the steps so when I do my 70cc kit.. I will be able to get a good long life and reliability out of my bike. I must say thanks, you taught me a lot about what my break in period should be.

_________________
04zuma 2t daily rider bike now has a technigas next r exhaust a piloni 70cc cylinder stock airbox with snorkel removed with 95 main jet and needle at its middle point right now ive got 6g and 6.5 gram rollers in the cvt stock clutch springs probly goin to try 5g nd 5.5g stricktly running premix also
near future goin to do a full race setup with a water cooled cylinder and full on build


Thu Nov 13, 2014 8:49 pm
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Joined: Tue Jul 08, 2008 9:16 pm
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Post Re: Break In
Your cylinder will come honed already - don't do anything to it!

And in my opinion you really don't want to do any of that shozzle with oil and stuff when you break it in. Just use your normal oil and follow a sensible break-in procedure.

The one I like is - after two or three short heat/cool cycles on the stand - 5 minutes ride/5 minutes rest; 10 ride/5 rest; 15/5; 20/5; 25/5; 30/5 and you're done. Take it very easy while you're breaking it in, don't push it above maybe 40MPH at first, and keep varying the RPMs as constantly as possible (I try to oscillate all the time). And don't wind it out - keep the RPMs at a moderate level.

It takes 2-1/4 hours or something. After that your ring(s) should be seated. I'd probably still still be a little cautious and not run any performance tests until I've gone through a couple of tankfulls, but it doesn't take long to break in a kit on the Zuma...my guess is because the RPMs are high in small-displacement engines.

Cwoodar0 hasn't been here for a while, but he's an eccentric kid - he has a lot of spirit and likes to experiment with a lot of stuff. But I wouldn't necessarily take his crazy advice. :)

_________________
'05 Zuma 50, Athena sport 70cc (12mm piston) with Polini head (.9 squish), B9ES spark plug; timing advanced about 2˚; Yasuni C16 exhaust, Buzzetti kick stand to make room for it (and Stage6 paddock stand after dropping the freaking bike because of the kick stand); stock airbox no snorkel, 5 x 1/2" holes; Stage6 21mm racing PHBG, 45/95/W7 1 lean/40 slide; Polini/Power One 12mm HPC crank; Athena 15/50 gears (also have 14/42s pressed into a gearbox cover, just switched back and like the 15/50s so far); 107mm Malossi Delta clutch, "racing" red springs/lighter "racing" counterweights ± 6800 RPM engagement, Stage6 Kupplungsglocke (bell - the light one); Malossi 6112811 Overrange kit, red contra and 28.2G rollers; VForce 3 reeds; Michelin Bopper tires; back to the stock shock; dual headlight wiring; C3 mirrors; Trailtech TTO tachometer and temp gauge.


Thu Nov 13, 2014 10:21 pm
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Joined: Mon Sep 23, 2013 8:29 pm
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Location: Lansing, MI
Post Re: Break In
Meh. I just heat cycle it a handful of times, ride it moderately a few times, and go. Never had a ring go brittle on me.

If it's a *new* kit and you're not sure about your tuning, then you'll want to be more careful. Overheating can definitely cause a brittle ring, so you want to be careful until you know your temps are gonna be fine.

As far as seating, it's gonna happen one way or the other. I don't worry about it. Never glazed a cylinder, either.

Much ado.

_________________
08 Zuma "The Fly" 50: Stage6 Racing Mk.1 (0.7 squish), Athena Race exhaust (S6 Pro), Malossi RHQ crank, Doppler 15/50s, Dellorto 21mm PHBG DS (60/42/90), Top Perf. Vforce3 reed valve, Malossi Multivar w/drive face, Malossi Delta Clutch & Wing bell (Yellow contra, yellow clutch springs on stiffest), Stage 6 R/T forks, Stage6 R/T 4 pot brake, S6 280mm big brake, Aerox 100 rims, S6 CNC'd controls, Brembo master cylinder, Hoca/Bando ignition, naked bars, manual petcock, Pirelli SL26s, dual light mod, re-profiled seat, LED signals, doodads and gizmos (TT Vapor, Harris Project R1 grips, silly stuff) and always running Amsoil Dominator.


Thu Nov 13, 2014 11:56 pm
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Joined: Tue Jul 08, 2008 9:16 pm
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Post Re: Break In
I've read posts about blowby because the ring didn't seal properly, so I'm cautious.

Most recently I replaced my piston and ring, and I honed my Nikasil Athena lightly with a ball hone made for cast iron (because that's what I have, and I just did one quick dip on each side with an electric driver at low speed). I was a little worried, so I was extra careful breaking it in. It's working fine.

_________________
'05 Zuma 50, Athena sport 70cc (12mm piston) with Polini head (.9 squish), B9ES spark plug; timing advanced about 2˚; Yasuni C16 exhaust, Buzzetti kick stand to make room for it (and Stage6 paddock stand after dropping the freaking bike because of the kick stand); stock airbox no snorkel, 5 x 1/2" holes; Stage6 21mm racing PHBG, 45/95/W7 1 lean/40 slide; Polini/Power One 12mm HPC crank; Athena 15/50 gears (also have 14/42s pressed into a gearbox cover, just switched back and like the 15/50s so far); 107mm Malossi Delta clutch, "racing" red springs/lighter "racing" counterweights ± 6800 RPM engagement, Stage6 Kupplungsglocke (bell - the light one); Malossi 6112811 Overrange kit, red contra and 28.2G rollers; VForce 3 reeds; Michelin Bopper tires; back to the stock shock; dual headlight wiring; C3 mirrors; Trailtech TTO tachometer and temp gauge.


Fri Nov 14, 2014 12:23 am
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