Big Bore Break In
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Big Bore Break In
So for those of you who have been answering my posts thank you for your input, Bear and Wheelman particularly. As of now I am having my cylinder bored to 44mm for Tazlands piston kit on its way. I have am also about to order a 78 jet to replace my original for the larger displacement. Now I just need to know if there is anything else I should machine for clearance issues and how to break in the new cylinder. I have gathered that I need to heat cycle the engine, but I was wondering what the Bear thought as the best way to do this would be.
Re: Big Bore Break In
Don't rev it up on the stand
Don't give it WOT
No long pulls under load (high speed runs/hill climbs)
Vary the throttle/rpm. Dont let it sit and idle, don't hold it wide open, don't cruise at the same speed. Your wrist should constantly be moving, if only a little.
No top speed tests at all, no matter how short
Start small on the heat cycles (I went with 30 secs, 1min, 2min, 3min, etc. Didn't start riding until I was up to 5min)
WAIT A LONG TIME in between heat cycles. It takes at least 2-3 hours for everything to cool down fully, maybe longer. This is usually the hardest part, since you'll be itchy to ride
EDIT: Forgot to mention add extra oil. Figured it is common sense but I'm pretty familiar with this stuff.
Don't give it WOT
No long pulls under load (high speed runs/hill climbs)
Vary the throttle/rpm. Dont let it sit and idle, don't hold it wide open, don't cruise at the same speed. Your wrist should constantly be moving, if only a little.
No top speed tests at all, no matter how short
Start small on the heat cycles (I went with 30 secs, 1min, 2min, 3min, etc. Didn't start riding until I was up to 5min)
WAIT A LONG TIME in between heat cycles. It takes at least 2-3 hours for everything to cool down fully, maybe longer. This is usually the hardest part, since you'll be itchy to ride
EDIT: Forgot to mention add extra oil. Figured it is common sense but I'm pretty familiar with this stuff.
Last edited by 808BMW on Tue Sep 15, 2009 1:06 am, edited 1 time in total.
In 2040 they say we're going away
We could never let them control
Hawaiian man, take back your hawaiian land
We could never let them control
Hawaiian man, take back your hawaiian land
Re: Big Bore Break In
So how after I start riding it after the said 5min heat cycle, what should I do? I am guessing the same procedure for a couple of tanks of gas?
Re: Big Bore Break In
topic related question:
is it safe to break in an engine during winter? i plan on installing/breakin in my bore kit during winter when practical riding is impossible due to cold temps
is it safe to break in an engine during winter? i plan on installing/breakin in my bore kit during winter when practical riding is impossible due to cold temps
Re: Big Bore Break In
why is that scooters require a LONG cautious breakin?
as opposed to your run of the mill "dirtbike"stroker water or air cooled ?
facts not fiction are what i'm looking for here...
as opposed to your run of the mill "dirtbike"stroker water or air cooled ?
facts not fiction are what i'm looking for here...
busting my knuckles on vices since
for long as i can remember
for long as i can remember
Re: Big Bore Break In
I have to admit, as a long time racer of 2 stroke powered karts, scooters (Go-Ped style, with engines that can do upwards of 20k rpm) I have always found the best break in method to be ride it like you stole it while making sure to give varying amounts of throttle and check tuning often. I can't really see why it would be different for these scooters, given that the engine design is basically the same except for a case reed (most Go-Ped engines are piston port, though you can get aftermarket cylinder and case reeds) and iron cylinder (aluminum/Nikasil in the Go-Ped world).
That said though, I can't really say I've seen much of a difference in performance/longevity no matter what type of break in is used, though a little extra oil and care never hurt. It's mainly got to do with long term treatment of the engine and proper preventative maintenance.
That said though, I can't really say I've seen much of a difference in performance/longevity no matter what type of break in is used, though a little extra oil and care never hurt. It's mainly got to do with long term treatment of the engine and proper preventative maintenance.
Re: Big Bore Break In
exactly what i thought.
as long as jetting is correct for the state of tune and the oil/gas mixture stays
where it needs to be then a generaley quick break-in is fine.
while i have your attention-
i brought home a 88 Jog 50 last week and after the usual carb cleaning, pulling the cylinder and checking for obvious flaws i reckoned it had enough compression that it ought to at least run.
well the short of it is the exhaust was completely clogged.i drilled some new holes so it would exhale.
well after a few shots of ether it lit but it would only run at near wfo.
checked the float level - o.k.
anyway i was able to get the engine to"idle if i held my hand over the carbs intake
tightly.
i think the crank seals are fubared, possibly from the sealed off exhaust.
thoughts?
as long as jetting is correct for the state of tune and the oil/gas mixture stays
where it needs to be then a generaley quick break-in is fine.
while i have your attention-
i brought home a 88 Jog 50 last week and after the usual carb cleaning, pulling the cylinder and checking for obvious flaws i reckoned it had enough compression that it ought to at least run.
well the short of it is the exhaust was completely clogged.i drilled some new holes so it would exhale.
well after a few shots of ether it lit but it would only run at near wfo.
checked the float level - o.k.
anyway i was able to get the engine to"idle if i held my hand over the carbs intake
tightly.
i think the crank seals are fubared, possibly from the sealed off exhaust.
thoughts?
busting my knuckles on vices since
for long as i can remember
for long as i can remember
Re: Big Bore Break In
I know both methods of easy/hard break in, and they both have merits.
The simple reason I recommend easy break in: It's almost impossible to mess up.
Breaking it in hard (through hard acceleration/deceleration) requires that you know what you are doing. Engine must be in a good state of tune (hard to ballpark if you've never built a motor), needs to be warmed up properly, cooled down properly, etc. If you can break it in hard and not blow up your bike, you shouldn't need to ask anyone about it.
Personally I also feel that due to our CVT trans, deceleration doesn't put enough negative load on your rings.
The simple reason I recommend easy break in: It's almost impossible to mess up.
Breaking it in hard (through hard acceleration/deceleration) requires that you know what you are doing. Engine must be in a good state of tune (hard to ballpark if you've never built a motor), needs to be warmed up properly, cooled down properly, etc. If you can break it in hard and not blow up your bike, you shouldn't need to ask anyone about it.
Personally I also feel that due to our CVT trans, deceleration doesn't put enough negative load on your rings.
In 2040 they say we're going away
We could never let them control
Hawaiian man, take back your hawaiian land
We could never let them control
Hawaiian man, take back your hawaiian land
Re: Big Bore Break In
i'd really like to know how the tazland kit performs. please tell when done! nobody on here seems to report how well those kits work out