Difference between 139qmb and 1p39qmb? By jwest1990 (Read 25,227 times)

[jwest1990]

I've read a couple different things online but almost everything I've heard is different. Was just wondering because I just got a new 2013 TaoTao Thunder 49cc and it says 1p39 qmb and everybody else I know with a scooter says 139qmb. Anyways, your help would be much appreciated. Thanks

[Alleyoop]

Look on the rear of the engine case, on the part of the case above the rear axle by the rear brake pads there may be a stamp either 5B or 6B.

5B means it's a 49.5cc, 6B it's a 63cc.
Alleyoop

[royldoc]

There is no difference in the two engines. The "P" designates that it is a horizontal cylinder. Some manufactures stamp the "P" in the engine code and some don't. I have 4 of these engines and two of them are stamped 1P39QMB and two of them are stamped 139QMB.

The first digit designates the number of cylinders:1=1 cylinder

The next letter designates the lay out of the cylinder: P= horizontal, V=v type, Blank=vertical. Some manufactures do not stamp this digit as all 139QMB, 1P39QMB engines have a horizontal cylinder.

The next two digits designate the bore size: 39= 39mm bore

The next letter designates the type of cooling: Q= forced air

The next letter designates engine use: M=motorcycle

The last letter designates cc size: B= 50cc

None of my engines are stamped at the rear of the case with 5B or 6B. The engines may or may not be stamped.

Hope this helped.


Roy

[kz1000st]

Wait, I know this. A 1P57QMJ has a head tuned for more torque, power and mystical properties. I'm betting a 1P39QMB may have more mythical power than a plain old QMB. Some of the Bashan motors even had the secret 62cc cylinders. I just swapped a P head for a regular head on my 150cc Bashan and it won't burn rubber anymore. Of course it didn't do burnouts before but the mystical power must be gone.

[royldoc]

The 139QMB engine in my trike came from IceBear with a secret 72cc engine. All the "P" denotes in the engine code is the direction of the cylinder. the heads are the same. I have several heads by different manufactures. the specs are the same, valve diameter, valve length. cam size, ect.. I get better performance from one of them over the rest. not because it was tuned for a "p" engine but because of the small differences in manufacturing. such as a smaller combustion chamber. when you order an after market head they don't ask if it is a 1p39qmb or a 139qmb engine, because there is no difference.

Roy

[cdoublejj]

i rode a VIP with a secret 60cc cylinder we always wondered why it so much faster than the big wheeled 50cc scooters. this is what push me towards to upgrading to 60cc instead on an 88 or 100cc BB kit.

[portcitypetino]

I have a brand new Ice Bear Q6 50cc trike coming in, will it have the secret 72cc engine by chance?

[Alleyoop]

If its a TRIKE the motor may have a bigger displacement ONLY because of the extra 100lbs it has to pull. Otherwise people would complain that a 50cc trike is a real dog and word of mouth goes out and they would not sell to many 50cc trikes.
Alleyoop

[portcitypetino]

But they are advertised as 50cc's so by that logic wouldn't they sell more if it were advertised as a 72cc? I'm kind of confused now, lol, sorry!

[Alleyoop]

You need some learning BRO, ever hear of the EPA and DMV rules IF a scooter is under 50cc and does not go more than 30mph in a mile you do not need to register it or licence it IN MOST STATES.

If they advertized it as 72cc or 63cc then they would need to register it a license and in most states also prove of insurance and you would have to take the driving and written test.
Alleyoop

[portcitypetino]

You know what, it didn't dawn on me until your reply, but you are exactly right, I did know that, I was JUST having this same convo with a buddy of mine at my local bike shop! So, back on subject, is it safe to assume then that the Ice Bear Q6 trike is, indeed a 72cc as opposed to the advertised 50cc based on the fact that it is hulling an extra 100lbs give or take?


I always forget about the DMV rules simply because I already have my motorcycle endorsement from riding bigger bikes so I never needed to think about that! I also always fully insure my vehicle no matter what it is unless the insurance company says I can't! I originally came from scooters though and they are more my style, I like it toned down but in style.

[Alleyoop]

I say yes, but I do not have a 50cc trike but everyone that has one they say it does near 40mph.
Even Jim From Rapid Repair that he did the PDI on them for the customers had the suckers up there.

[portcitypetino]

Lol sorry Alley I got everything except that last part about the suckers.

[rapidjim]

I think what Alley meant was suckers = 50cc trikes. Think he also missed a word typing, should have been Even Jim From Rapid Repair that he did the PDI on them for the customers that had the suckers up there.

I have not tore down a 50cc Ice Bear trike yet. Haven't had one fail or a request for a bigger displacement, so I can not tell you if they big bored them at the factory or not. It could be gearing that is the difference. The only way to be sure would be to open one up and measure the bore, there is no way to tell by the outside looks of the motor, that is how many get away with big bore kits because the physical looks are the same and it would be a waste of time and money for law enforcement to tear one down to check. Lots of States have a MPH rule for 50cc Moped Class scooters, some are 30 and some 35. Wisc is currently 30 but is revising their staute.

Good luck with your Q6 and don't forget to do a good job on your Assembly and PDI. Also, not sure if your dealer told you, but make sure to take the rear wheels off and take them to a tire shop and have them spun balanced. Also make darn sure to check that the rear hub nut is tight and the cotter key is in the castle nut.

[portcitypetino]

Thanks so much for the info Alley and Jim, much appreciated! I'm actually purchasing it from Mega Motor Madness and I'm paying extra for the full assembly and PDI service (bought a 2 wheel before with same services from Power Ride Outlets). And I will DEFINITELY take your advice on the rear wheels being spun balanced and check the hubs and cotter keys! Could you tell me what spun balanced actually means by chance? I just learned what laser alignment meant a while back as I have a Can-Am Spyder clone from Kandi Motors as well lol!