New Rider
Currently Offline
Posts: 1 
Likes: 0
Joined: Dec 12, 2016 21:06:13 GMT -5
|
Post by scooterbl2 on Dec 12, 2016 21:38:23 GMT -5
Hello I have a question about breaking in my new bbk i installed, and the crank shaft i replaced. I was wondering if it was possible to passively break in my scooter by keeping it on the stand strapping it to a saddle like device to keep it from vibrating some place or just make a wooden stand to sit it on and having the air intake get air by using air compressor to blow air into the filter area to prevent any over heating? I would love to drive it but i live in a city with crazy drivers that make me question the dmv. I could run it for 1000 miles no problems on the stand, however i don't know how that would effect the break in process since there is no load on the engine. They don't take much load to begin with but when i do drive i have to drive about 40 miles a day in a 50 so breaking it in to work and back is not an option. I want to leave it running in outside my garage and just let it knock some miles off the break in process for me. Anyone see any problems with this? I can fix the throttle at half so it isn't pulling too many rpm's i got a tach meter attached.
For the specs of things changed normal run of the mil qmb gy6 engine better crank installed to support 50mm big bore kit. New carb with a adjustable mixture screw and 80 main jet 37ish idle! Amazed i could not adjust those on the old carb and the mixture screw was fixed... Scooter brand name wolf Rx 50. Need any other info? I can provide actual product information on the installed parts if asked. I'm looking for options that don't require me to drive it. That's the goal here.
|
|
Sophomore Rider
Currently Offline
Posts: 183
Likes: 4
Joined: Mar 4, 2013 19:49:04 GMT -5
|
Post by 4950cycle on Dec 13, 2016 0:54:31 GMT -5
JCL MP250A Lihai 257cc powered / The only thing I can think of that your plan does not allow for is there should be variations in your rpm while breaking in. You are not supposed to be at one constant rpm while an engine breaks in. Constant rpm makes more heat than an engine accelerating and decelerating here and there. Higher operating temps are not an engines best friend while breaking in. Aside from that AFAIK there is no law that says an engine must be under load while breaking in.
|
|
|
|
Post by bandito2 on Dec 13, 2016 0:59:05 GMT -5
The only option that I can think of that wouldn't require you to drive it would be to have
somebody else drive it. Running off 1000 miles in a garage? No way I see that working...
though I did see where a guy put about 5600 miles on a Honda Elite scooter and about
1800 miles on a Honda PCX... in his driveway.
However, I still don't think doing this would be a proper break in method either. I really
think it needs to be put under load. WHAT!? You'd leave it to run unattended? No way
I'd even think about doing that.
BTW, when were you ever going to ride it? It might take a while but you might think
about riding it yourself on your days off from work.
|
|
|
|
Post by rockynv on Dec 13, 2016 1:52:54 GMT -5
You need to load up the crank and accelerate varying the throttle and load to break in the kit so running it on the stand with no load is not going to seat the rings to the bore very well and could create a damaging harmonic vibration that would damage the piston/cylinder. Accelerating under a moderate load forces the piston rings into tighter contact with the cylinder walls to get them to conform better during break in and really critical to the process.
The Wolf RX 50 is a 40/45 mph 50cc bike for riding on 30/35 mph roads so even with a 80cc BBK your pushing it on a 50 mph road where traffic is likely flowing at 55 to 60 with the insane going 70 mph. An entry level 125/150cc is really the minimum for that type of service. Bumping it to 80cc should just make it more reasonable on a 35/40 mph road so that you are not running wide open all the time to keep up with traffic. Its still going to be one of the smallest small frame 50cc scooters once all is done and not the safest size bike for a 40 mile daily commute on a 50 mph road.
Break it in putting around town in the evening or the coming weekend for a few hundred miles or so varying the throttle, change the oil at around 400/500 miles and then you should be passable for your commute as long as you don't go too wild. What type of results were you expecting to get from the 80cc BBK?
|
|
|
|
Post by dollartwentyfive on Dec 13, 2016 7:10:34 GMT -5
the entire reason for break in is to provide a means for the various parts of the engine to perfectly mate with one another.
this mainly applies to the piston and crank, but it also applies to other parts of the engine.
i'm not sure whether a stand can provide a proper break in environment, but i do know that the rings need the vacuum of a closed throttle to seat properly..
the best procedure, in my opinion, is, run scoot for about 15 minutes at idle (for warm up), then a WOT acceleration to almost max RPM, followed by a completely closed throttle deceleration to about 30 MPH, then repeat without the 15 minute warm up.
the MPH figure depends on engine size, the figure i gave was for my 250.
|
|
|
|
Post by rockynv on Dec 13, 2016 12:44:12 GMT -5
Its compression that expands the rings and seats them to the cylinder wall while vacuum releases them to allow oil film on the cylinder wall for the next compression and combustion stroke. WOT from a dead stop should be avoided during break in as would gunning an unloaded engine. A new cylinder should not be pushed past 2/3 of its top speed during initial break in.
A 15 minute warm up is too way too long at a constant speed for new cylinder and can cause harmonic buzzes and rattles that will stay with the bike for the life of the rebuild and can lead to prematurely wearing out.
|
|
|
|
Post by dollartwentyfive on Dec 13, 2016 15:51:35 GMT -5
Its compression that expands the rings and seats them to the cylinder wall while vacuum releases them to allow oil film on the cylinder wall for the next compression and combustion stroke. WOT from a dead stop should be avoided during break in as would gunning an unloaded engine. A new cylinder should not be pushed past 2/3 of its top speed during initial break in. A 15 minute warm up is too way too long at a constant speed for new cylinder and can cause harmonic buzzes and rattles that will stay with the bike for the life of the rebuild and can lead to prematurely wearing out. sounds reasonable to me. however, i don't think there is a "standard" break-in procedure. most car makers frown on flat out acceleration, just like running close to max RPM. i believe that there is some kind of "breakover" point in breakin. a point where you get the absolute maximum HP from your engine, and i'm not talking about RPMs. so, there is an advantage for a proper breakin. no, you won't destroy your engine if you don't break it in, but you CAN get just that tiny bit extra HP if you do it right. BTW, a "premium" built engine will probably not need a break in these aren't the days of "ye old bridgeports". no offense to bridgeport, i cut my teeth on them. |
|
|
|
Post by rockynv on Dec 14, 2016 1:10:09 GMT -5
Still need to run it in to get combustion pressure to seat the rings by getting behind the bevels and such. Yes some are run in under a load at the factory by a computer to minimize user run in before you buy them however in the case of the original posters home installed Big Block Kit you still need to go through the basics to ensure longer trouble free life and better performance.
Just had an old timer who always followed the run in by the book sell his Scarabeo 500 GT Touring scooter with 138,000 miles on it and still running great without a rebuild. You will see more of those coming from folks who followed the run in by the book than from the folks who did not and more typically had to rebuild their engines before 50,000 miles.
On my 250cc Aprilia the book said to run it in with no low speed full throttle acceleration for a set mileage and to refrain from speeds over 55 mph or riding at a constant speed until after the run in oil change and then gradually increase the speeds you ride at over then next few hundred miles. Following the book exactly my Aprilia at 30,000 miles burns no oil and still runs like new with the added plus that I get an extra 15 to 20 mph top speed (almost 100 mph) compared to those who did not follow the run in procedure specified in the Aprilia Owners Manual (around 75/80 mph).
|
|
|
|
Post by ricardoguitars on Dec 14, 2016 7:18:33 GMT -5
Ride it like you stole it! Just don't stay on high RPMs for extended periods of time, you shouldn't do that even after break in anyway.
|
|
|
|
Post by cyborg55 on Dec 14, 2016 9:35:23 GMT -5
Ride the thing alright already
|
|
