OzVMX Forum
Marque Remarks => Suzuki => Topic started by: twinrock on November 15, 2016, 02:40:58 pm
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Hi guys i have been lookin for a lil bike to club rego and ride off road.. i have a dt200 motard set up that i love but its a pain swapping wheels over , i have been lookin at dt175 250 IT175 and the like but thought id consider a suzuki , im about to pick one up.. very clean twinshock 81 model sounds and runs nicely..but i was expecting more bottom end..well at least some bottom end....it seemed very flat untill it came on pipe..and took awhile to get there..does this seem indicative of the power characteristics..are there ways to improve bottom end pull..im happy to sacrifice a lil top end for some more off throttle response.but not looking at doing major work..sometimes easier to buy a different/bigger bike thanks very much
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I have an '81 RM125X, and was similarly dismayed.
1. Check your ignition timing.
2. Carb/jetting? Mine had a replacement carb. An off the shelf Mikuni in stock size. I made useful advances with jetting changes. Basically after getting it as close to stock as I could. NOS needle for e.g. I found raising the needle made improvements with each change. I ran out of grooves and bought the next richest needle jet, which should put the clip back in the middle so I can continue experimenting.
3. You get used to it and keep the revs up. :P
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I had an 81 pe175 and although it wasn't an arm-tearer, the power was very linear, and had decent bottom-end. I'd be checking your carb etc
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Why not check out what the magazine tests said back in the day here
https://onedrive.live.com/?id=407D7EF0965D3991%211089&cid=407D7EF0965D3991
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Ahh thanks for that..yeah well the magazine review also concurs with my thoughts of the power characteristics ...well is there anyway to improve things or just accept and ride
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buy an it175 :)
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buy an it175 :)
Or better yet, buy an IT200 :)
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Chapter eleven of the Clymer manual discusses performance improvements for the PE models
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buy an it175 :)
Or better yet, buy an IT200 :)
yeah i had initiallytried to find a good 175 or 200 but budget didnt allow it. i traded pe175 for another bike so no cash was exchanged ..like i said i have a very well sorted dt200 , pipe ,carb ,reeds, which makes great power everywhere but i hve to swap to dirt wheels over when off road ..i do really like the idea of something simple and dedicated to total off road use..thansk for your input guys.. i may just move the pe175 on..
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Nothing wrong with a well set up PE, back in the very early 80's we did a lot of carnage to everything including open class on a PE175C, me thinks it was the suspension set up that did it! then again it was an ex Chris Gizza setup! just my opinion
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I would say a pipe mod would be worth investigating if you dont mind trading off a bit of top end for bottom end. Speak to Lozza, for some suggestions if you are open to a few mild complimentary mods for the PE. I would tend to think a lean towards a 'Plonker" pipe design would offer a better bottom end. Take a look at most ag bikes (2T) and you will notice the longer thinner mid pipe section, see the Suzuki TF range for ideas.
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Take a look at this TF125 Pipe
http://moto.zombdrive.com/images/suzuki-tf-125-4.jpg
Obviously designed to perform best with the TF gearing and porting, ignition etc. but sort of illustrates how the AG bikes get good tractable power from a 2t engine. Perhaps a mild tweak could help customise the power characteristics you prefer?
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Yeah i agree about the pipes and their design purposes .. i did have a lil chat with lozza the other day he suggested a 250..i would swap some top end for more bottom..i realize there us no free lunch... anyway i get the bike on friday ill go over it make sure its all as it should be before i do anything else thanks again
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Pe175 was never designed for bottom end. However a Ts185 was. Porting isnt as sharp so it pulls ok for a tiddler and it shares the same flywheel as the 250.
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The trick is to remove the Muffler restrictor / or use an aftermarket muffler. Next thing get your jetting sorted as they tend to run a bit rich.
Pe 175 perform better higher up in the revs, and once you have the flywheel spinning they are a fun thing to ride.
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the pe175 is a rip tearer once you get them right. there is a bit to do. 1. alloy muffler, 2 timing set to specs. 3. rejet to suit.
from the factory they were restricted and once they were removed, you had to reset timing jetting to std as they were altered to cope with the restrictors.
obviously now it would pay to strip motor and redo seals, and while its apart, get the transfer ports matched to the barrel and get the barrel ports tidied up as in open up and clean all dags, match them to the base gasket etc dont remove any metal from the barrel, leave the port timing std. clean up the intake port and knife edge any dividers etc.
check the exhaust pipe, they may be double walled so a real good clean would be in order. a new carb would be best unless its in real good low hours condition. boyson reeds top off the package.
you should finish with a real snappy quick revving engine, not a great bottom end engine but something that jumps into the band at the snap of the throttle and pulls hard across the range. would be fun to ride, a real zinger!
if you want a bike that crawls up hills in 3rd gear at 1000 rpm, the pe isn't for you! KDX 250 is the standout tractor of the 80's aircooled engines
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..................... knife edge any dividers etc.
Under no circumstances should that ever be done on any engine. I forgot about the pipe restrictors they are worth removing.
Increasing the compression ratio will help bottom end.
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please explain? Knife edging?? whats the deal?
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I have a 83 PE 175, not so good down low but when you keep the revs up its quite good, very nimble in the tight stuff but it's a single shock. I have a 80 PE 250, it pulls real well down low, my choice of the 2 for power delivery, it would have been great if the 250 carried on for another year or 2 and they built a single shock floater.
Cheers Pete
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Yep the knife edging is a sure sign of a back yarder with a die grinder from supercheap who is all of a sudden better than Frank Pons because he heard from a mate this is the go........
If I pull a barrel that the back yarder has knife edged, I usually resign myself to sourcing a replacement barrel beacause if someone has gone that far it is not too much of a stretch to believe that other "performance Mods" have been carried out. I pulled down an engine not long ago that had the classic houso porting plus a turbo crank - slotted with a grinder (but get this-it was done in situ!!).
Moral of the story is do your research, get the word from an expert or pay an expert to do the work. (discuss what you want from the engine)
Generally the factory has researched and developed the design to very acceptable standard, manufacturing flaws such as dags in the casting and port mismatch is usually the only work required to get good reliable power from a Jap performance engine.
Blue printing the stock engine will be best place to start in most cases, that way you will know how well the engine will perform as the manufacturer intended. This is a good place to start - baseline the bike - suck and see.
Carefull attention to detail makes a noticeable difference and is indeed all that most privateers delve into ie; blueprinting, carefull attention to build up and test and tune until the bike is dialled in to suit the rider.
If there is any short fall, performance parts are added to fix the short comings - emulators, aftermarket silencer/exhaust, carb, bars, pegs, springs etc.
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please explain? Knife edging?? whats the deal?
It has to do with sonic and sub sonic air flow. Like aircraft wings sub sonic aircraft have rounded leading edges on the wings and sharp trailing edges. Super sonic aircraft have sharp leading edges on the wings. There is no super sonic flow in an engine , therefore it is a pointless exercise.........not that I've ever done it ;D ;D ;D
Yep the knife edging is a sure sign of a back yarder with a die grinder from supercheap who is all of a sudden better than Frank Pons because he heard from a mate this is the go........
If I pull a barrel that the back yarder has knife edged, I usually resign myself to sourcing a replacement barrel beacause if someone has gone that far it is not too much of a stretch to believe that other "performance Mods" have been carried out. I pulled down an engine not long ago that had the classic houso porting plus a turbo crank - slotted with a grinder (but get this-it was done in situ!!).
Ha ha nearly spat my coffee everywhere. I'm even thinking now that removing dags and gasket matching is a WOFTAM. The next biggest sin is the step at the exhaust flange/cylinder, which is put there deliberately. Imagine what a Supercrap die grinder could do to this 54hp $5000 cylinder :D :D :D :D
(http://i155.photobucket.com/albums/s297/Lozza85_2007/edgeradius.jpg) (http://s155.photobucket.com/user/Lozza85_2007/media/edgeradius.jpg.html)
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LOL
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that cylinder should be in the Guggenheim ;)
for a little bit of $$ at a muddaboik man, the tidying up of the transfers and cleaning up of the edges is worth the $$.
its basically a blueprinting, not a "port job"
I have not suggested in any way shape or form that the port timing be altered. I have had considerable success doing this to several bikes ive owned.
this is just making the engine as good as it can be to compliment new seals bearings etc etc.
it seems to me to be a waste of time to split cases and spend a $k + refreshing the bottom end and not blueprint the ports especially if there is considerable gasket overlap and thick daggy bridges....
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old small files round/flat/square profiles bent to shape are good for tidying up the ports and for a few hrs work of blending youll get good gains for little money and a freer reving motor
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if you think that all that will make a difference it will regardless of what a dyno or a stopwatch will tell you. In a kart catagory I was tuning engine in there were specific rules against cutting your own base gaskets and having a large over lap, I always wondered why until we tried it. The overlap actually made the duct more efficient(engine could be leaned off and was 0.2-3 sec faster) as it was to big and the wrong shape. With 2 strokes nothing is as what it seems.
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so your saying abit of base gasket protroding in the transfer ports causing an restriction is a good thing??
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supersonic air in them cart engines :o
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if you know what your doing with ports and the effect a change has on the rest of the engine then it can be a good thing but if you dont then best go to the fridge and grab another beer and put the tv on and watch the cricket. i think we all know that if you pick up on one area it has to come from somewhere else.
All Ive ever done to a top end is basic clean up and match the ports and the piston skirt to the factory specifications, smooth exhaust port and CC. yeah Blueprint.
End result is stronger smoother engine performance that comes close to the factory sales blurb and still have reliability and a tractable engine.
i kind of like the notion of sand cast intake having a larger effect of emulsifying the fuel vapour more than a smooth intake that would only have drag and emulsifying effect on the peripheral zones. Im probably wrong but for no effort it works good and if it was good to have a smooth intakewhy didnt factories just do a straight clean machined intake and why did suzuki create the TSCC (twin swirl combustion chamber) on its 4t GSx750?
i have 'corked" a counterweight and i think it went better but i was 17 at the time so maybe the fumes or my mates sister made it feel better.
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Wow this has certainly turned into quite the discussion, i am no expert and am still learning the mystery of the 2t engine even though i have been riding and building them for 20yrs now..mostly road yamaha twins and Suzuki..but loving dirt riding now but know very lil about the bikes..yes knife edging has been frowned upon for sone time now over the rounded transfer bridges..i agree that manufacturers know what they are doing..BUT.. still have to make compromises due to noise, emissions and reliability constraints. They also suffer the flaws the mass production brings So in my experiences the general tidy up of castings and transfer flowing does make a notable difference..its seems to make more if whats already there..not change the characteristics of the motor the way making changes to ports does..so back to the suzuki pe175 it would seem that the performance characteristics i have questioned are the general census..no clean up or knife edging is going to change that ..only port timimg and an exhaust to match...thanks guys i have enjoyed the lesson
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The next biggest sin is the step at the exhaust flange/cylinder, which is put there deliberately.
Really?
I blended this on an RM125 in 1981 as a bit of an afterthought.
It made such a difference I was kicking myself for not doing it earlier.
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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 :)
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as Pauline pants down said ''please explain''
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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
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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.
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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
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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.
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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/
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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
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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
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http://www.ozebook.com/index.html
look up Bulletin 17 L-M-N for factory specs
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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
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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
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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
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the old I should have looked first post ;D
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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..
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And yet to commit to the purchase.. i bought the bike based on the info from tnis forum????
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Good little bike the PE, just takes a little to get use to how to ride it and get the most out of it.More than capable of going just about anywhere but it isnt a trials bike by any stretch . My first ride on one i hated it Felt like I had to wring its neck to make it perform. I prefer my not so peaky engines for tight stuff but i wouldnt turn my nose up at a nice PE.
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look at it this way ...its not a 125 being throttled pinned wide open nor is it a 250 with plenty of mid range ..... its a mix of both and will be a fun bike once you accept what it delivers.
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And make sure the pipe has minimal carbon in it. My mates PE175T was getting a bit sluggish, so we cooked the pipe out, and it lost a fair bit of weight, and regained some performance.
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so your saying abit of base gasket protroding in the transfer ports causing an restriction is a good thing??
Sounds counter intuitive but it actually worked with 30% of the duct area shrouded. If you look at the Hessels cylinder pic you will see a big difference between the duct entry and exit areas of the A & B transfer ducts. Small entry area leading to big exit area. That way the intake discharge maintains superior direction when the transfers start to flow as more volume is held in the duct(intake charge does not go from carb to combustion chamber in 1 cycle) . Result was less intake went straight out the exhaust, cooled the piston better which in turn allowed leaner jetting.
In the case of a gasket sticking out a bit between the cases and cylinder will make no measurable difference, though as my mate put it "increases the overall impression ratio" ;D
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Hessels cylinder.
I was meaning to ask, what's the story with the pictured cylinder?
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anyone had a look at the pics on Ian Williams tuning iwt.com.au just saying, Ive been tinkering for a few decades and still learning what I thought I knew is wrong