44mm spree big bore kit installation time!!!!

[Spreetard]

so... 78 jet?? i was going to step down to an 85, with no air filter it runs up pretty well untill high rpm's on the 95 it runs ok... i was thinking about boring the intake and exhaust port also...

[Spreetard]

You don't have to wait until the premix is burned up. The original jet was a 68. You only increased displacement 3cc. That's not a whole lot, definitely not deserving a 95. Tazland needs to send a smaller jet than that . I would think a 78 would be more appropriate.

He increased it 8cc, from 49cc to 57cc

And that is still way less than a 10% increase. I agree, a 95 is over kill and being that rich can retard break-in or ruin the bore.

ruin the bore. exactly what i don't want to do.
i figured running it rich with heavy oil would keep the bore cooler and slow the heat cycle, along with keeping everything nice and oily, well lubed and whatnot. with no air filter in place, it runs very strong, 4 strokes at higher speeds. still havn't tried too hard as the second tank of gas just got put in. rings seem to be seating nicely, as the required amperage to crank the engine has gone way up. no follow up compression test yet, i'll do it tomorrow.
how much will my 30:1 mix prevent it from running right?? i didn't think it was TOO overboard...

on a side note, i have the throttle adjustment needle clip on "rich", if i knock that down a bit it may run better. kinda an epiphany i just had... i just put it the same as on my other scoot...never looked back.
input is greatly appriciated. this is the biggest 2 stroke undertaking i've had yet.

[Bear45-70]

Here is a large CC 2 stroke nightmare. It's only 1637cc (99.9 CID) with a carb for each cylinder.

[Spreetard]

Here is a large CC 2 stroke nightmare. It's only 1637cc (99.9 CID) with a carb for each cylinder.

what is THAT from????

[Bear45-70]

Here is a large CC 2 stroke nightmare. It's only 1637cc (99.9 CID) with a carb for each cylinder.

what is THAT from????

A Mercury Marine outboard race motor called a Twister IIX for racing in the SST (Super Stock Tunnel) class. They would turn around 8400 RPM make better than 260 hp but didn't live long the high. They lived long and won at 7600 to 7800 though.

[toboggan]

It's a nice looking straight 6 however!

[carp]

You don't have to wait until the premix is burned up. The original jet was a 68. You only increased displacement 3cc. That's not a whole lot, definitely not deserving a 95. Tazland needs to send a smaller jet than that . I would think a 78 would be more appropriate.

He increased it 8cc, from 49cc to 57cc

And that is still way less than a 10% increase. I agree, a 95 is over kill and being that rich can retard break-in or ruin the bore.

All very true.Tazland stated in some past post that he was going to start sending #85 jets insted of the #95 jets.Carp

[Spreetard]

moved the clip to leanest setting, still running rich. smaller jet needed. must order for make good runningness. (i speak fluently in badly translated japanese service manual)

[bradthreee]

I wouldn't count on the info tazland sends. To be honest, I don't even think he did any research or testing of his product before selling them. He basically just put together a bigger piston, bored out the cylinder, then sold them as big bore kits. In all reality they are "big bore kits", but unlike a Polini or Malossi, thousands of dollars of research and development were not spent to make them true bolt on kits. Just keep that in mind when you throw on that 100 or 95 main jet he sends with the kits

[Spreetard]

belive me, i've found that out. the 95 will might work with a tuned pipe, but i still think it would be too much. the stock airbox is completly out of the question. as of right now, even the tube that connects the stock airbox to the carb with no filter attatched makes it run like crap. only with an open carb can i get any kind of speed, and only 30mph at that, which can only be achived at half to 3/4 throttle. the plugs come out black as night, but that's also from the 30:1 mix gas. untill i can get a new jet, the project will make little progress.

[maddog]

What is the purpose of this top end only engine build, i hope its not about speed

[Lunytune]

What is the purpose of this top end only engine build, i hope its not about speed

I don't know about others, but for me it's torque. I realize part of the problem with the NQ50/SB50 is in the straight drive transmission, but I would like to make every effort to improve takeoff and power. So the ovebore is a reasonable and cost effective way to do a rebuild. I wouldn't do it unless original jug lost compression and needed rebuilding anyway.

[eliteguy50]

I don't know about others, but for me it's torque. I realize part of the problem with the NQ50/SB50 is in the straight drive transmission, but I would like to make every effort to improve takeoff and power. So the ovebore is a reasonable and cost effective way to do a rebuild.

x2,advantages: overbore, porting, increased compression, cheaper than new oem...

[Lunytune]

x2,advantages: overbore, porting, increased compression, cheaper than new oem...

Just for the record on the cost factor: In ignorance, I originally took my LX jug to Hondasan for rebore (worn beyond specs.) and parts. Cost was going to be over $200. Because of inefficiency (kept it over a month, no action), I picked it up and went with daywot's kit for less money. If all you need is rings and maybe piston, it might be cheaper to stay stock, but even then it doesn't take but a few more dollars to go with the overbore. Definitely cheaper than Hondasan.

[toboggan]

wheres the throttle adjustment lever? lol