Anyone know who is doing these...?

http://www.ebay.com/itm/80cc-66cc-M...d=100005&prg=1088&rk=5&rkt=5&sd=221262940332&


Just curious if this is a forum member....

Map

MotorBicycleRacing said:

I hate vague subjects like these or that? you couldn't have thrown on Port and Polished Cylinder Head Rings and Piston?

They are in Dover Arkansas.

Seriously a much better choice would be to get ported cylinders from a pro who knows what they are doing and wins races.

High Performance Ported Piston Port Cylinder from Arrow all the way.
About the same money too.

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LOL..! NOPE! the way I did it got ya here and got a response, that is what I was shooting for!

I have no intention of purchasing this set of parts, I do my own rookie style port work, works good for me, got 48mph with an NT carb and a $5 home built exhaust, plenty of low and mid power as well so I'm plenty happy with my own work. I'm not looking to break records or go 50+ mph on my bikes and the work I do gets me 40+mph cruise speed which is all I'm wanting on any of my bikes.

the jug and parts I listed are probably a good deal for the fella looking to add a little power and speed who doesn't have the tools to do the work themselves, but you're correct in saying that they would probably be better off in the long run just going with a reputable china girl builder like Arrow, Fred or Jakes.

as my question indicates I was more curious if the person doing this was a forum member so I could ask for more detailed pix of the transfers and intake port work, best I can see what is shown in pix looks pretty good as far as being nice and clean, transfers look to be cleaned up nice on the inner edge and the exhaust port looks good from what can be seen, ports dont have to be raised and lowered to see nice performance benefits in my experience, just really smooth clean ports make a really good difference.

The highly restrictive aluminum intake would be a joke to use on a well ported jug though for sure....LOL!

Thanks for the reply MBR

Map

bill2781 said:

hey mapbike if you don't mind me asking what sprocket do you use ? .

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Don't mind you asking at all friend, I enjoy telling people what I have and do to my bikes and hope that they will have the same results or even better than I do, I'm not one of the high end racers on here as it is obvious, but I do enjoy some added performance and better cruising speeds on my bikes.

Now all that said, on my last build I was using an NT carb with jet drilled with #72 wire gauge bit after I soldered it closed, a Puch 70cc hi hi head which helps it run cooler up top and might have added a tad of performance I was running the dax slant head that has the better squish band, honestly couldn't tell it worked any better than the standard slant head, but to answer your question about my exhaust, Yes the exhaust I had on the bike when it was at its fastest top speed was a home built rig that was basically a straight through design, I did use the header pipe from a kit exhaust and I worked out the flange where i bolt to jug so that it is a s closely matched to the port as possible so that exhaust could flow out without running into any flat surface and would have a smooth taper into the pipe.

I could cruise on the flat at 42-45mph and hit around 48mph on a slight decline with very high revs, I ran a 34T and a 36T with bike set up this way I described above and had about the same cruise speeds.

I have since made some changes on the bike, I installed the Dellorto Clone/RT carb and I built a header pipe for a X1/X2 pocket bike expansion chamber I had and have done some modifying to the silencer on the chamber to get it to flow better, now the bike has loads of semi low to mid range power and my cruise speeds on the flat have dropped to 40-42mph, the RT carb made the engine way more responsive and acceleration has been very noticeably improved but I'm certain that my top speed loss is due to a way small restrictive header pipe I made up for the new expansion exhaust, the reason I changed exhaust was to quieten the bike down because with the straight through pipe it was very loud, performance was there though because it would scream at over 9000 rpm and maintain close to 40mph on the slight hills we have around here, it still pulls my slight inclines good but it peters out on the top end because of the flow restriction in the header pipe I made up for it, which will be resolved when I have the time to build another header pipe.

so to sum all this up....LOL!

With a well ported jug, a well tuned carb, a good free flowing exhaust, a 36T rear sprocket, a bike that has good wheel bearings that aren't causing excessive drag, brakes that arent dragging against the rims and a rider at 217lbs --> (thats me...LOL!) 40+mph is doable on the flat without major head wind and such.

I have two engines that have had no port work with well tuned carbs, one has SBP exhaust and the other has one of the $40 banana expansion pipes on it, both of these top out in the upper 30's and cruise nice in the lower 30's these two engines are BGF ebay engines and get crazy vibes above 30mph on one of them and above 34mph on the other.

The fastest bike(40+mph one) is running one of the better built & better balanced lowers I purchased from Duane at thatsdax, and I did what I think turned out to be some good port work on a jug I had that was off of an older LEB/BGF ebay engine I had.

In my experience at least well deburred and matched as good as possible ports, well tuned carb and and exhaust that flow really good are the best mods to shoot for and then if the engine isn't just wildly out of balance like my two old BGF engines you should see 40mph and maybe a little more as your top speed with a 36t rear sprocket, just be aware that you will be spinning that engine at some serious rpms at that speed with a 36T and you better have an upgraded upper wrist pin bearing or you may hand grenade the little sucker......LOL! (Ask me how I know......!)

well I'll end this book now.

Peace, Map

Huffydavidson said:

If you want to buy a top end already ported and polished then buy one of the kits from RC machine or David Rust. Not some dirt road hillbilly it doesn't have a clue because he's already drank too much moon shine.LMAO

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I reject your reality and substitute it for my own...........!

(I'm the "dirt road hillbilly" in this story and I do my own port work and it works pretty dang good for me.....LOL!)

For top performance it is true that the major builders have done there homework and can provide better high end performance from there jugs and parts, but.....YES there is a but in here.....single T mind you...!

For someone who wants improved performance on more of a budget and doesn't want port timing changes that may kill some of there low end cruising around town power, just a well cleaned up jug with the ports polished on the exhaust side and slightly widened and deburred on the intake side and the transfers deburred and having the ridges ground out will make a few MPH increase and help at the midrange rpm also, but yes for all out speed seekers who don't care about loosing a little on the bottom and plan to do all the other mods needed to make the high end jug work beneficial the Fred, Arrow or Jakes cylinder and parts are top of the line from what I have read, no first hand experience with them though and my work get s me cruising nice at 40+mph with plenty of midrange pull for the hills so for me I cant justify spending $80+ on a jug and parts when I can have just what I want with an $18 jug and an hour or so porting work that includes some minor ramps on the piston at the port openings and the skirt notched out to clear intake port.

I'd say 9000+rpm at 40+mph cruise and a top speed of 45+ aint bad for some dremel tool work of a "dirt road hillbilly" and by the way i'm a bit on the Red Neck clinging to my God & Guns side also....LOL!



Peace, Map

bill2781 said:

thanks mapbike for answering that post I am kinda like you I want my bike to top out around 45 to mabe 50 so I can cruse around 30 to 35 all day. and not worry about it blowing up .

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You're very welcome, with my current set up it looks like I'm gonna end up with either a 30 or 32T rear sprocket on mine so that I can have a 40mph cruise speed and a top on the flat at 45+mph, I did a GPS 'd speed run today after putting my non expansion exhaust back on my bike and I found that right now I have a top speed on the flat of 43.0MPH with a 36T rear sprocket, my engine has good porting and th RT carb which seem to have knocked 1-2 MPH off my top speed but it is way more responsive than the stock NT carb I had on it, my engine has good power like it is so I'm pretty sure I can knock 4-6 teeth off the rear by dropping in sprocket size and get the cruise speed back where I want it and still have it nice and ridable in the 30-35mph range as well, the expansion pipe I made up hurt my top speed and didn't do as much as I had thought for the low to mid range power, thr RT Dellorto clone carb was where I got my nice boost in low to mid range acceleration, so I'm keeping it on the engine for sure.

50mph is doable but only with serious mods and high gearing which will limit use when needing to putts around town at lower speeds, I'd suggest staying with a simular set up as mine and then you can have 40+mph top speed and still putts around OK when you need to and it will run great in the 30-35mph range, I know mine does, it just purrs like a kitten at 35-37mph and then it will wind on up to 43mph on the flat really quick if I want to run all out.

Map