4t tuning thread

[Buckets4Me]

Can I suggest a CBR125 re sleeved. Cooling sorted.

why re sleave it just wack in a 100cc piston

[bucketracer]

why re sleave it just wack in a 100cc piston

Yep, wack it in through the spark plug hole! that way you get to adjust the valve clearances at the same time.

[SS90]

Hey Woodyracer, does the cam you ordered come with any specifications?

[TZ350]

Lots of handy 4-stroke calculators http://www.rbracing-rsr.com/calculations.htm like dynamic compression, camshaft data, and inlet runner size. But be prepared to work in cub in and degrees F so you will need converters for those to.

Temperature converter http://manuelsweb.com/temp.htm

Inch/Centermeter converter http://manuelsweb.com/in_cm.htm

Cub Inch to CC converter http://www.metric-conversion.net/con...entimeters.htm

You can use these calculations on a 2-Stroke too if you remember a stroker fires every revolution so passes twice as much air as the same size 4-stroke doing the same rev's and every thing happens in half the time on the stroker so the 4-stroke runner lengths are halved and areas doubled.

[Buckets4Me]

Hey Woodyracer, does the cam you ordered come with any specifications?

ye 2 big lumps

[SS90]

let's try not to ruin this thread with childish stuff aye, because, well, really, we all know your dad just looks up stuff, reads it and posts it (but admittedly quite often tests it for himself, which, clearly is a great thing for others to watch), and you and your brother don't even do your own tuning work....(need I go on?)in an ideal world Woodyracer can learn and come up with his own work, constantly belittling him is both un-nesessary and childish, perhaps if you or your brother could come up with something insightful instead of silly replies (kind of like 2 little bullies at a kindergarten who need their ego's pegged down) you could encourage him to learn and post his results here.

Perhaps if you spent more time improving your riding skills your team may stand a chance at getting some tinware, because, despite Teezee's hard work, I still have not heard of any success.....although Teezee himself did actually get third in the GP last year...on a 15HP machine, and f5dave was "waiting for him" to have someone to ride with, (I have raced against plenty of the RG50 crew "back in the day", and beaten them all on a 13HP GN125, along with Cam Horgan who had substantually less power again than me, but still diced with me for the lead every single lap), so I assure you it can be done) so that just goes to show the level of competition, as was proven when some of the south Island boys came up and showed everyone a clean pair of heels.

Before you go off on some childish vendetta, just remember I am only writing the facts.

I hope Woodracer can give us some more information on the stuff he has brought, because if it is any good, he would be well advised to get the cam profiled before he fits it, and with a little research/experience, he may be able to improve on what he has brought.

I worry about the lightweight piston though, so much material removed from the skirt like that is quite risky (on all but very expensive pistons), I am curious as to how much power it all brings.

I also wonder if it will be a considerable advantage to him to remove the injections system, and simply fit a carb of, say, a mid eighties DR200 (flatslide), it will require some rewiring of the loom (to accommodate the loss of sensors), but (from personal experience) it's quite easy.

The big advantage is less weight and the ease you can change the jetting etc with a carb.

It will rev out faster with a flatslide too....the EFI system is for pollution levels, not power (on this sort of machine)

[bucketracer]

let's try not to ruin this thread with childish stuff aye, because, well, really, we all know your dad just looks up stuff, reads it and posts it (but admittedly quite often tests it for himself, which, clearly is a great thing for others to watch)........I have raced against plenty of the RG50 crew "back in the day", and beaten them all on a 13HP GN125

Yes you are quite right, Dad has already said something to us about discouraging Woody..........

Clearly Dad understands a lot more than he writes, and posts excerpts and links that he finds, because they articulate a point, he would like to make, better than he can, or has the time too.

Some of his ideas are quite original, and you have been privileged to see the thinking behind them.

And something you could learn from, TeeZee doesn't need to tell people how good he is or was he just lets his work do the talking for him.

[NOID]

[/QUOTE] I also wonder if it will be a considerable advantage to him to remove the injections system, and simply fit a carb of, say, a mid eighties DR200 (flatslide), it will require some rewiring of the loom (to accommodate the loss of sensors), but (from personal experience) it's quite easy.

The big advantage is less weight and the ease you can change the jetting etc with a carb.

It will rev out faster with a flatslide too....the EFI system is for pollution levels, not power (on this sort of machine)[/QUOTE]

would he not be better to leave the EFI and find a piggy back / tunable ECU ? even reflash the existing. i have no idea ithe gear is out there for this kind of bike, but it does exist. then he could download basic map setup found on the net and then adjust it with laptop .... i know this sounds way to advanced/flash for bucket racing.

[Buckets4Me]

let's try not to ruin this thread with childish stuff aye, because, well, really, we all know your dad just looks up stuff, reads it and posts it (but admittedly quite often tests it for himself, which, clearly is a great thing for others to watch), and you and your brother don't even do your own tuning work....(need I go on?)in an ideal world Woodyracer can learn and come up with his own work, constantly belittling him is both un-nesessary and childish, perhaps if you or your brother could come up with something insightful instead of silly replies (kind of like 2 little bullies at a kindergarten who need their ego's pegged down) you could encourage him to learn and post his results here.

Perhaps if you spent more time improving your riding skills your team may stand a chance at getting some tinware, because, despite Teezee's hard work, I still have not heard of any success.....although Teezee himself did actually get third in the GP last year...on a 15HP machine, and f5dave was "waiting for him" to have someone to ride with, (I have raced against plenty of the RG50 crew "back in the day", and beaten them all on a 13HP GN125, along with Cam Horgan who had substantually less power again than me, but still diced with me for the lead every single lap), so I assure you it can be done) so that just goes to show the level of competition, as was proven when some of the south Island boys came up and showed everyone a clean pair of heels.

Before you go off on some childish vendetta, just remember I am only writing the facts.

I hope Woodracer can give us some more information on the stuff he has brought, because if it is any good, he would be well advised to get the cam profiled before he fits it, and with a little research/experience, he may be able to improve on what he has brought.

I worry about the lightweight piston though, so much material removed from the skirt like that is quite risky (on all but very expensive pistons), I am curious as to how much power it all brings.

I also wonder if it will be a considerable advantage to him to remove the injections system, and simply fit a carb of, say, a mid eighties DR200 (flatslide), it will require some rewiring of the loom (to accommodate the loss of sensors), but (from personal experience) it's quite easy.

The big advantage is less weight and the ease you can change the jetting etc with a carb.

It will rev out faster with a flatslide too....the EFI system is for pollution levels, not power (on this sort of machine)

HA ha thats rich coming from you
childish indead

you couldn't go one sentance without having a stab at someone

[SS90]

would he not be better to leave the EFI and find a piggy back / tunable ECU ? even reflash the existing. i have no idea ithe gear is out there for this kind of bike, but it does exist. then he could download basic map setup found on the net and then adjust it with laptop .... i know this sounds way to advanced/flash for bucket racing.

Yea, for sure, I think piggy back systems are around $NZ450, and it would soon start to become a money hole, with, in my experience, no, or even less advantages than simply converting to a carb.

Carbs are plentiful, easy to tune (well, mostly) and by comparison, cheap. Even one carb off a bank of 4, (off, say a mid eighties GSX-R-750 for example) could be used.

I#m not saying "this is the best way to do it", but I think, in my experience, it will be the best dollar for dollar tuning he could do.

Systems like the one on Woodyracers bike are designed for low emissions opposed to high horsepower, and lack the complexities required to make power at the same time.

As an example, there are plenty of FXR150's that put out more than 20PS (and these are air cooled, and admittedly 25cc's bigger, oh, and D.O.H.C), but, they are simply carbed.

Granted, with the lesser spec of the Honda engine (the water cooling also is only to keep it at the correct temperature required to pass E4 rules, opposed to allowing higher compression ratios, and the higher power you can achieve with this) more than 20PS is unlikely (but perhaps not impossible...... I remember some VERY fast S.O.H.C cam CB/XL125's "back in the day", so, that sort of power is clearly obtainable.

[richban]

The latest idea to get a little more power over 3/4 throttle to full throttle. D shape the top of the carb. Will let people know if it makes any diff. Mikuni TM28 Attachment 194399

Just finished rebuilding the carb all fitted up and ready to go. I will post results after some testing. Need to order some more main jets, now running a 540 hex head main. Just under 2mm. The standard engine was running a 280.

[SS90]

Just finished rebuilding the carb all fitted up and ready to go. I will post results after some testing. Need to order some more main jets, now running a 540 hex head main. Just under 2mm. The standard engine was running a 280.

Erm, I don't think that's correct..... "more than 2mm" for a main on an FXR150?

Have a quick search on the web to find out how much fuel that will flow in a minute...... I don't think an FXR150 can do that.......... ready to learn though!

[Pumba]

........Even one carb off a bank of 4, (off, say a mid eighties GSX-R-750 for example) could be used........

Hey thats my idea, infact the very carbs you are talking about are sitting in the shed ready to go, must get round to fitting that one day.

[richban]

Erm, I don't think that's correct..... "more than 2mm" for a main on an FXR150?

Have a quick search on the web to find out how much fuel that will flow in a minute...... I don't think an FXR150 can do that.......... ready to learn though!

Yeh can't find anything. I have been playing with the carb and jetting for about 6 months and this is where its at. I was plug chopping it at Manfield and it had a nice full turn of colour after a good 30 seconds of full throttle running. I had it on the dyno but that was a wast of time as it had a manifold leak that didn't get found. Its not your average FXR engine.

[TZ350]

I was plug chopping it at Manfield and it had a nice full turn of colour after a good 30 seconds of full throttle running.

Hi Rich, A 70's TZ with 34mm carbs run 320 or so hex head mains. A 540 main jet is so big it suggests something else is metering the fuel at full throttle. Have you tried a run with no main jet, it should bog on full throttle but if it rev's out the needle/jet combo is to small and is controling the mixture at WOT, not the main jet or there is another restriction like the float needle/seat or tap/filter, dangerous stuff.

Or it could be your carb is so big that there is not much air velocity induced vacuum and you need a realy big jet to provide sufficent area for the reduced vacuum to draw fuel from.

All sorts of info on tuning carbs here:- http://www.sudco.com/mikuni.html