pe175 performance questions

[Rossvickicampbell]

slightly off the topic question - has anybody had any experience with the "honeycomb" flow porting system?  Does anyone even know what I am referring to

[TT5 Matt]

as Pauline pants down said ''please explain''

[Terrapista]

I have a pe250c with a 38mm carb (pe400). Does this mean i lose at the top end and gain at bottom end? In turn,  does it mean i lose power but makes it more torque? Gears are are standard at 13t/52t but i take it that sprockets is for the powerband. Not sure if carb is set up for 250 performance. I have not ridden it yet so would i be able to tell at all or should ride as is and just enjoy as i dont know any better.
Im bought it for some flat track and vinduros so obviously differing set ups involved for both.
Cheers

[80-85 husky]

engine / carb size is all about the flow rate of the fuel air mix at any rpm. the bigger the carb the less speed the fuel air mix has. thus bigger carbs only work well at high rpm when the speed of the mix gets high enough. a small carb will work best for low rpm as the mix speed is high at low revs but reaches terminal velocity before peak rpm and the engine chokes. add ign timing, exhaust design etc and its easy to stuff up by fiddling.

early pe's were designed for a bit more low end than later (t,x z)which were basically a/c rm's with a flywheel.

[shelpi]

get ya squish area right, factory's allow for upto 0.8 mm intolerance due to piston lengths, conrod length's and cylinder height
so correct cc in the combustion chamber with the correct squish then less to no detonation and a nice clean burn with out over heating the engine from reduced power to seizure

[pokey]

slightly off the topic question - has anybody had any experience with the "honeycomb" flow porting system?  Does anyone even know what I am referring to

Never done it but have read a tad on it. The school is still out on if it has any benefits over a random surface . In theory... exact design should produce better results  however as the lesions are uniform in size and angle and the velocity of the charge is not uniform then  its like a broken watch, correct two times a day.

[skypig]

get ya squish area right, factory's allow for upto 0.8 mm intolerance due to piston lengths, conrod length's and cylinder height
so correct cc in the combustion chamber with the correct squish then less to no detonation and a nice clean burn with out over heating the engine from reduced power to seizure

The 2 stroke specialists TSP, offer a service where you measure your squish, and send the head only for fine tuning. From all I've read, it's one of the best improvements, especially on a modern bike that probably has pretty clever porting and pipe already, but a compromise (for obvious reasons) on the squish dimensions.

http://twostrokeperformance.com.au/measuring-squish-clearance/

[shelpi]

get ya squish area right, factory's allow for upto 0.8 mm intolerance due to piston lengths, conrod length's and cylinder height
so correct cc in the combustion chamber with the correct squish then less to no detonation and a nice clean burn with out over heating the engine from reduced power to seizure

The 2 stroke specialists TSP, offer a service where you measure your squish, and send the head only for fine tuning. From all I've read, it's one of the best improvements, especially on a modern bike that probably has pretty clever porting and pipe already, but a compromise (for obvious reasons) on the squish dimensions.

http://twostrokeperformance.com.au/measuring-squish-clearance/

don't forget when the engine is rebuilt (again) it will have to be matched again with base gasket etc but the bloke from TSP will fill you in on the details

[twinrock]

What i need to do is make sure all the specs are right.. anyone got the  carb specs for this model and expected compression psi.. to start off with thanks

[Oldfart]

http://www.ozebook.com/index.html

look up Bulletin 17  L-M-N for factory specs

[LWC82PE]

Standard jetting specs from new which was for 20:1 premix can be found in the factory service manual here. Don't look at the Cylmer manual because it was written based on the US market bikes which may have had different jetting? Also look at the scanned parts books.
https://onedrive.live.com/?id=407D7EF0965D3991%211086&cid=407D7EF0965D3991

E24 is 'Australia' so look at specs for E24 model. Also sites like CMSNL.com and Mick Hone suzuki may also list jet/needls sizes in the parts lists so look there too.

Almost all info is out there for these bikes. You just need to look

[supermotomc]

Ok eyeball the expansion chamber your looking for a set of spot weld marks cut behind  through the chamber 90% open up! you see why it doesn't go! cut grind out the restriction weld back together burn out pipe ! if you have the original tail pipe leave it where it is. burn out drill 1x 8 mm hole through spark arrester check reed for fibre ,open the reed stoppers 3-4 mm  new piston rings

[twinrock]

Well i had a quick look at the bike today starting with the airbox and filter..the air box had no lid just a big round hole..not sure it this is factory..now get this..the air filter was made from a round chinese container with some slots cut into it and wraped in matress type foam taped up with electrical tape..i took it off and adjusted the needle height till happy..big difference..midrange heaps stronger as well as top end..i will go over carb and check pipe next as well..i think this bike will be just fine now..i knew it had to have more then what it had

[80-85 husky]

the old I should have looked first post

[twinrock]

I know..how ever i was yet to pic up the bike.. i only got it in my hands late yesterday ... i had riden it and it sounded fine but just lacked the power i would have expected..hence the post..it still lacks bottom end..but not as bad as before..