157QMJ BBK By Alleyoop (Read 3,110 times)

[Alleyoop]

Hi Troops,
I am thinking about putting a BBK on my 157QMJ(149.6cc) engine. I am thinking about the 61mm(170cc) BBK from Scooterworks.com which does not require milling the Case. Does anyone know how many EXTRA HP that would add to an engine.
Alleyoop

[jake aka:ventoscoot]

I have no idea on the added HP. I do know that some of the kits allow for not boring and some do, regardless of claims. I have heard of some that are able to be used without boring and they have very (read: VERY) thin cylinders that can have durability problems. Keep us posted on your results.

[Alleyoop]

Jake,
Thanks for the Heads Up I will make sure and ask about that before going for the one that does NOT require milling the case.
Alleyoop

[jake aka:ventoscoot]

Hell, the NCY 59mm kit I originally had and had the cracking issues with the cylinder had thin walls, thinner than the new 59mm kit I have.

[robb]

I have seen the dyno for that kit. It showed 11 hp! with stock head and 90 jet. It was on scooterworks but they seem to have pulled it. Scooterworks has it listed as aluminum but it is actually iron. I would think think that a cast iron cylinder of any given thickness could be much stronger than an identical aluminum one depending on the heat treating. It looks like a fast, significant, displacement gain. Whether it's good or not ; I think it depends on NCY's metalurgy. Robb

[rapidjim]

I went and read the info on their site and one thing I noticed was this " In addition, its recommended to get our 61mm big valve head as well, as some stock heads will not fit. " That statement prompted me to do a little more research and came up with this from MRP:

I also saw this statement "As far as we know, this is the only 61 mm cylinder kit for the GY6 engine that exists in the US. " This prompted some more research LOL. I did find that MRP does offer a 61mm GY6 kit, PN N-MP-0944C, sadly it is out of stock right now and no information except it is a 61mm. Sooooooooo, I wrote Joel and email asking him,
1. Does the case require boring for this kit to fit?
2. Is the jug aluminum or cast?
3. Will the stock head fit?
4. When is the expected date to be back in stock?
5. Who is the manufacturer?

I will post the results as soon as I get them. One other thing is the MRP price is lower on my site, even lower with the forum discount. Now does this mean that the MRP kit is an inferior setup? At this time I can not answer that question sense I have yet to try one.

Jim/Owner
Rapid Repair

[robb]

The scooterworks page is poorly set up, the copy poorly written and it's mislabled as aluminum. Of course it isn't the only 61mm in the US. I think they meant to say the only 61mm in the US that doesn't require boring of the case. I'd wager it is simply NCY's 59.5mm iron cylinder bored out with 61mm piston. Whether it's good or not will likely depend on the metalurgy. A cage camshaft is usually hard and can snap like glass. A good conecting rod will bend instead of snap. The question is; how hard is the cylinder? Robb

[Alleyoop]

WOW!! Thanks guys, I surely do not want something that is not reliable and cause problems.
I am not going to be hot rodding just want more power at all speeds and to be durable.

If a good combo is recommended and it needs taken some off the case then maybe I should just go for the 63mm which I believe is a 180cc BBK. I do not know a damn thing about the BBKs and will take any advice given.

Jim thanks so much for your researching and will wait for your questions to be answered and your thoughts on which way to go. If boreing is required for a 61mm why not then go for the 63mm???

Would a 63mm be a much better solution than a 61mm any trade-offs or concerns on either one?
Alleyoop

[rapidjim]

Alley,

This is the link for the 63mm kit which is also out of stock right now. www.rapidrepairpowersports.com/SPD/n-mp-09519--800008C0-1178919756.jsp

The description states that this kit may require case boring. It is $50 more, but less with your discount.

Still waiting on Joel to answer.

Jim

[jake aka:ventoscoot]

here is the 63mm kit from scrappy dog: www.scrappydogscooters.com/125_150cc_Performance.html I really think the 59mm kit I have from them, is far superior to the ncy one I had.

[rapidjim]

Nov 16, 2010 19:42:33 GMT -6 jake aka:ventoscoot said:

here is the 63mm kit from scrappy dog: www.scrappydogscooters.com/125_150cc_Performance.html I really think the 59mm kit I have from them, is far superior to the ncy one I had.

Wow that is a great price. I am going to have to look to see why the MRP kit is higher priced.

Jim

[rapidjim]

Sorry this took so long to get, but I ran out of time to write a reply yesterday.

1. Does the case require boring for this kit to fit? In MOST cases anything over a 59mm will require case machining. Be leary of those that say it don't.

2. Is the jug aluminum or cast? All BBK with the except of 62mm are cast.

3. Will the stock head fit? Depends on the original motor Some will some won't. See .


4. When is the expected date to be back in stock? Would take a couple days to build a kit, the only kit available for shipping right now is the 62mm.

5. Who is the manufacturer? Generic/MRP

As far as cost is concerned there will be some price adjusting going on with my website in the next couple days. Takes some time due to codeing issues. I want to be more competitive on these kits, but don't want to go broke doing it. There is one website (won't say the name) that has lowered his prices so low it is unbelievable, but he makes it up in Shipping and Handleing.

On another note, if you find a part on my website that you think is out of line price wise, let me know in an email or PM and I will look into it. With 1000s of parts I have access to in the MRP warehouse, it is hard for me to check each and everyone for price comparisions. Another thing is please don't mix apples and oranges when price comparing, some parts are cheaper elsewhere for a reason.

Jim/Owner
Rapid Repair

[bige]

I have run the ncy 61mm slip in cylinder on several gy6 150's. all had trouble with the lower section of the sleeve cracking. I now run the ncy 59mm kit with no issues

[rapidjim]

I have gotten some more info. I made a few phone calls and the consensus I got was: 59mm kits are a direct fit, 61mm kits require case milling in most cases depending on the motor and kit used, 62mm, 63mm and 64mm kits DO require case milling. I was also told that using the 63mm and 64mm can crack the case. more so with the 64mm. To use a 63mm or a 64mm kit, the cases need to be strengthened were the jug sides in by a machine shop capable of doing that and "line bored".

I also have been working with my warehouse on pricing of these kits and some other items. I hope to have the new prices on my site this weekend to be more in line with other "reputable" dealers. I doubt if I will be able to compare with "some" of the Ebay folks, but a lot of them only sell parts, meaning they don't other tech support or even work on scooters like those of us in the above banner ads. Bashan does a great job of weeding the bads ones out of his banners.

Jim/Owner
Rapid Repair

[rapidjim]

Prices changes are done!!!!!!!

scooterdoc.proboards.com/index.cgi?action=display&board=parts&thread=2404

Jim