High Performance Wally World Cruiser?

[mapbike]

Forgot to mention on the GT5 bottom end I used a PK80 jug that I sanded down quite a bit. Probably could had sanded down more, but I will go from there and see what I get.

PK80 jug needs about .080" - .100" shaved off the deck to give good compression, if it isnt good enough you can always remove it and have more taken off, but honestly a little sanding down is a long way from what it will take to give that engine good compression with a PK80 jug on it, just saying this so if you have a very low powered engine when you get it going you know why and it can be fixed by taking a good bit more off that jugs deck to get compression up where it should be.

I ordered this jug for the GT5 lower I bought from you, this is an actual GT5 jug and gives a decent deck height, I shaved .030" off mine to get a good squish and bump compression on the engine but this jug will give decent performance at it stock height on a GT5 with just spome good cleaning of the ports.

http://www.ebay.com/itm/66cc-Motorized-bicycle-skyhawk-motor-cylinder-/221369946503

Here is the GT5 high pin piston also
http://www.ebay.com/itm/80cc-Motori...-motor-only-complete-piston-set-/321415387043

Seems when you find a vendor who only sells the high pin pistons, you also find that that vendor sells only the GT5 type jug because they deal with the GT% type engines.

 

[YesImLDS]

I shaved probably a few mm off the top, and it was getting to the point where I was getting only a few mm from the fins on the jug itself. I guess time will tell on that one!

 

[mapbike]

I shaved probably a few mm off the top, and it was getting to the point where I was getting only a few mm from the fins on the jug itself. I guess time will tell on that one!

If thats the case then you may have taken plenty off of it.

 

[YesImLDS]

It still had enough to clear the head as far as I know. I am running a double base gasket as well due to me shaving a little too much off the piston skirt on the exhaust side. I guess we will be able to know when I turn it over! I have an extra jug just in case anyways

 

[mapbike]

It still had enough to clear the head as far as I know. I am running a double base gasket as well due to me shaving a little too much off the piston skirt on the exhaust side. I guess we will be able to know when I turn it over! I have an extra jug just in case anyways

Best wishes and hope it works great for you, I'll be watching and listening for all the detail of how it works out when you get her busted off and on the road.

 

[YesImLDS]

Sanded down jug

Piston at BDC

Piston at TDC

Looks like more could be taken off too. No interference with the head.

Engine assembled

 

[YesImLDS]

Exhaust on

Exhaust oops. Didn't grind off enough of my welds for the bolt to fit. Looks like just another thing to hold me back! Ha

 

[YesImLDS]

Also Mikuni carb that will need some fabrication to fit properly

Need to figure out how to tune the dang thing too once that time comes.

 

[mapbike]

Well I really dont know where to start based on those pix YILDS....

Please take this as concern and not criticism, but your TDC is way off as far as an6thing close to ideal with that jug, some of it is due to you using two base gaskets and partly because the jug hasnt been shaved nearly enough to work good on a GT5 lower.

Second thing I think I'm seeing in the pic that shows piston a BDC is it looks like I can see the very top of the intake port slightly open qbove piston, this is also a bad thing.

The ramps on that piston are huge and that alone will take considerably from compression and your port timing is gonna be such that you may not have any low end power at all.

Please dont think Im hating on your work or being crotical of whT you have done because we live and learn on these engine by process of elimination sometimes, Imhonestly very concerned though about the areas I mentioned in this post and am afraid you're gonna have some issues because of the things I think Im seeing.

I honestly think an un-molested piston, a single base gasket and as thin of a head gasket as you can find or shave a few more thousandths off the de k and you'd have a better running engine.

I say give it a whirl but be prepared for some possible issues if what I think Im seeing is the way it is.

I know this all sounds so negative and Im sorry for that, I just really think you have a couple things working against what you're trying to acheive.

 

[YesImLDS]

Well I really dont know where to start based on those pix YILDS....

Please take this as concern and not criticism, but your TDC is way off as far as an6thing close to ideal with that jug, some of it is due to you using two base gaskets and partly because the jug hasnt been shaved nearly enough to work good on a GT5 lower.

Second thing I think I'm seeing in the pic that shows piston a BDC is it looks like I can see the very top of the intake port slightly open qbove piston, this is also a bad thing.

The ramps on that piston are huge and that alone will take considerably from compression and your port timing is gonna be such that you may not have any low end power at all.

Please dont think Im hating on your work or being crotical of whT you have done because we live and learn on these engine by process of elimination sometimes, Imhonestly very concerned though about the areas I mentioned in this post and am afraid you're gonna have some issues because of the things I think Im seeing.

I honestly think an un-molested piston, a single base gasket and as thin of a head gasket as you can find or shave a few more thousandths off the de k and you'd have a better running engine.

I say give it a whirl but be prepared for some possible issues if what I think Im seeing is the way it is.

I know this all sounds so negative and Im sorry for that, I just really think you have a couple things working against what you're trying to acheive.

I appreciate it. I'll give a look at it again in a little while. Like I said I haven't been feeling well and I might just invest in another GT5 top end so I can just have amatching set instead of forcing things to work. The piston was brought to TDC by hand so I could be very off. Could just be a weird reflection on the piston for intake port, but I guess I'll just have to take a better look at it!

 

[YesImLDS]

Also something I guess should be addressed it gaskets haven't been really torqued down yet so they will squish it quite a bit more. I'll put the piston at BDC and shine a light in it to see if I can see anything through the intake port.

 

[YesImLDS]

Also need to think about lengthening the exhaust so I have a little bit of a longer header and finding someone who can actually weld!

 

[YesImLDS]

Just opened it up again and sure enough the intake side is showing slightly. Guess I'll have to figure that out as well

 

[YesImLDS]

Well bicycle has been put on the back burner for a while due to a lack of funding. Opened a savings account a couple weeks ago and have been putting my money in there instead of the bike! I'll be back with more though in the short future!

 

[Semaj]

Gah, Im kinda at that point on my bike till mid next month, Hope its operatable currently so your not missin out on ride time.

 

[YesImLDS]

Gah, Im kinda at that point on my bike till mid next month, Hope its operatable currently so your not missin out on ride time.

Well it could be if I wanted to assemble it! I still have the motor I was using previously that still works perfectly. I'd have to switch over to my coaster brake wheel though. It's cold out and I am not missing out on much right now so I'll be just fine! Just need to get the bike worked out before I get too antsy and start missing things!

 

[mapbike]

Well it could be if I wanted to assemble it! I still have the motor I was using previously that still works perfectly. I'd have to switch over to my coaster brake wheel though. It's cold out and I am not missing out on much right now so I'll be just fine! Just need to get the bike worked out before I get too antsy and start missing things!

Hang in there brother, you'll have it going before long I'm sure...

Gonna be a nice ride when you get it to the point you want it, just takes a little time and a little cash to get them there.

 

[YesImLDS]

Hang in there brother, you'll have it going before long I'm sure...

Gonna be a nice ride when you get it to the point you want it, just takes a little time and a little cash to get them there.

Haha Cash wise I am not too far off! Just need another jug and piston which should be like thirty bucks. Need to get the fork threaded and cut which they said should be about twenty bucks and then I need to figure out my sprocket problems with the chain to figure out if it's a two different chain sized sprocket or I got something else going on. So I got <$100 left, but that'll be a couple paychecks before I have that $$$ with my savings plan I got going now! Good thing it's cold out still otherwise I'd be bummed!

 

[YesImLDS]

Also still got plenty to do on the bike it's just time now to do it as I got lots to catch up on from being sick and the girlfriend gave me a honey do list today... Damn women always holding me back! Haha just kidding.

 

[YesImLDS]

Does anybody know if a cruiser uses different style chain than a mountain bike would?