TM 32 jetting

[This old RZ]

You really cannot tell your plug readings from a photo...or just by looking at it

You should use a magnification glass to view the plug, As well as magnifying illuminated.
In addition. You generally DONT use the porcelain color to read your your jetting you should be read by the color on the base rings of the plug. Use of a glass was already advised in another post above ..its good advice. "I'm not saying its mandatory...but its advisable."

Also are you using any form of Mikunis tuning guides? and taking into consideration your altitude and temp? These carbs unless purchased bare..are usually pretty close. Mikuni has a downloadable PDF avail online, walks you through and guides you the basics for the TM/VMs. I also used the little pocket tuning/jetting calculator guide, I got from Doug at MOTO CARRERA, he said it was all I needed "besides practice" and would work like a charm...HE WAS RIGHT! I did two bikes a RZ and a 77 RD400 each with TM28s" street bikes, and it actually worked for me. This is after my friend left it at a motorcycle mechanic who couldn't get it alt all. Obviously not a good mechanic. IMO 32s are way to big for the street..I don't like the VAMPIRED low end performance & stuttering that is the Trade Off. But that's besides the point a lot of guys/tuners seem to prefer them and claim good results.

So hopefully you get it dialed in to your liking

Seriously...IF I CAN DO IT........YOU DEFINATLEY CAN

[T.RexRacing]

Yeah WFO WOT are one and the same.

If you look at the porcelain and see small black spots (pepper) that is a sign of detonation. They are bits of carbon liberated from the fuel due to extreme heat and pressure of detonation. An occasional bit of carbon on the steel is nothing to worry about. It's the porcelain that is important to watch. By the time the steel has heat problems we're in deep shit.

As far as advance curves go it would be hazardous for me to guess. A degree or two advance at high RPM until it says stop always worked for me.

[cookie]

Yeah WFO WOT are one and the same.

A degree or two advance at high RPM until it says stop always worked for me.

+1

[Bngt]

This old RZ please, I don't need comments which are picked from reading general information on the net. I can do that myself. There are thousands of opinions, mainly from people who have never tried themselves.
No the carbs are not pretty close, at least not to my application and they can be used for a variety, that is why there are such a wide range of jets. I hope sharing my experience will help others with a similar engine to pick jets which are closer to correct to start with. I searched but couldn't find this info for myself and therefore thought it would be appreciated. The bike goes like stink and I am sure that if someone else with my engine spec starts where I am now they will save some time. I have no stuttering and the low to midrange is impressive, maybe the vForce4 is helping or the Kenny pipes, I don't know but compared to a stock bike I have loads of more HP across the revrange and better drivability than stock. The questions are; are there even more to be found and am I safe?

Altitude is sea level and ambient temperature is 10C. We have 25-28C in a normal Swedish summer and if one is not on the edge there shouldn't be any need for rejetting.

There are many tells from looking at the top and electrodes besides looking into the plug and you don't need a lamp for that. As I wrote before I am going to start chopping plugs now that I am getting close to dangerous territory and do prolonged WOT runs. I am sharing photos for those who want to learn from a real life experience and the photos come out on my mac very close to what they looked like in reality. I appreciate the picture of the chopped plug T.Rex, how do you judge the mixture strength from reading that plug? Do you have samples to compare with?

Yes, I was looking for "pepper spots", which I have read about but never seen myself. Looks like I don't have that then.

I still do not understand why I should advance the ignition. Most of what I have read about twostroke ignition curves points at the value of retarding ignition to get increased rpm span with full power. Successive advancement sounds like fourstroke tuning to me.

[Bngt]

Some reading about ignition curves: http://www.dragonfly75.com/motorbike/timingcurves.html

[This old RZ]

This old RZ please, I don't need comments which are picked from reading general information on the net. I can do that myself. There are thousands of opinions, mainly from people who have never tried themselves.
No the carbs are not pretty close, at least not to my application and they can be used for a variety, that is why there are such a wide range of jets. I hope sharing my experience will help others with a similar engine to pick jets which are closer to correct to start with. I searched but couldn't find this info for myself and therefore thought it would be appreciated. The bike goes like stink and I am sure that if someone else with my engine spec starts where I am now they will save some time. I have no stuttering and the low to midrange is impressive,

FYI I DID it myself ...and it has worked just fine Sure ITS EMBARASSING TO ME that it required me 4 days to do it..instead of a 1/2 hr for a experienced guy..but I don't intend to do it very often. And was the 1st time in 2 decades I did attempt carbs..So that's why I threw a wish of support to you along with a good luck
As far as your slighted comment regarding "comments" ANY INFORMATION information posted on the internet by respected and qualified sources....IS THE SAME AS READING IT HERE AS WELL from .ITS THE INTERNET TOO. There NOT opinions they are facts of what many of the shops/indaviduals have used to do 100s ..make that 1000s of bikes. So you tell me ...whats the difference there. Its all 1st hand information based on real people and there willingness to help other enthusiasts ...like me...like you.
. So I'm not sure why you felt the need to be sarcastic. I'm sorry you feel, any "motivation" or suggestion was not helpful or maybe you felt that the comment regarding 32s are weak performers on the street offended you..I did say IMO. Your listed mods are not unlike many a RZ, so I don't really expect your bike to be too much different its power delivery as any of your forebears have been. And as far as the carbs not being "close" well that's the way it goes for you I suppose. Many times more often than not there "ballpark" I'm sure it depends upon where you ordering them from These came from Spec 2 and HVC and were told they were ballpark jetted, That is probably the reason why..no big deal. I didn't strip them down bare and start over..there was no need for me to do that. If I had then perhaps I would certainly have had a lot more difficulty , beyond my comfort level.

My reply was meant to be supportive and helpful and take from it whatever you feel was a nice gesture..It was in NO WAY intended as a ridicule of your methods & issues and troubles regarding your carbs. I don't really feel why you felt the need to bite a helping hand ..even if my comments were I your opinion ," not welcomed general information" ..you could have been polite and not commented at all But pehaps you took it out of context and thought I was preaching to you,,for which I assuredly was not ..it seems pretty obvious re reading it it was intended as help und best wishes.
I really don't get some guys sometimes..I've never dealt with any one like "some" the RZ here guys before. At the 2 stroke extravaganzas & vintage meets with other enthusiasts from novice to hardcore professionals" helpful and respectful, and many whom frequent this site There exists NO inflated egos nor I'll will toward anyone with a opinion
We have all have a good laugh over some beers at some of the sissy drama and " tarnished egos " that happens on this site sometimes. Lets not get caught up in that.

Again I wish you the best ! , Hope you get it sorted to your liking! , Lets leave it at that

[Bngt]

I don't like smileys that much, especially this one
and I couldn't find anything new or useful in your comments, sorry.
A pocket tuning calculator is mainly used for altering your jetting according to altering circumstances, once you have found an optimal setting, not very useful here, or can you use your calculator and tell me which jets I should use?

[Bngt]

There is four degrees difference in timing between the curves. The yellow being the retarded one. This is supposed to be a 50cc racer. Yes the white line shows a slightly higher peak but I would definitely prefer the yellow line.

[This old RZ]

I don't like smileys that much, especially this one
and I couldn't find anything new or useful in your comments, sorry.
A pocket tuning calculator is mainly used for altering your jetting according to altering circumstances, once you have found an optimal setting, not very useful here, or can you use your calculator and tell me which jets I should use?

1.) You don't like smileys?? Is that my problem?
2.)Okay nothing useful..that's okay. I find not much useful from many of you posts as well..but Id never post a reply to tell you that
3.) I'm going to keep my golden trusty lil pocket calculator....hidden from you smart ass...lol And FYI the MIKUNI PDF on setting up the VM/TM carbs was very helpful, to us. But beware it came from the internet

Basically you are obviously beyond my level of knowledge and mechanic and tuning ability..I think you will figure it out for yourself. Every single person whom as ever previously tuned my carbs , or friends bikes can do this very quickly and efficiently usually within the hour..Biganski, Doug and Steve, or Gary at Spec 2 and few others . No problems. Not me......but you... I feel will get there soon, again Best Wishes

[cookie]

What you say is true, too much advance will limit over-rev and can cause flattening of the power curve near the top. That said though unless you advance the ignition beyond where you are now you can't know if you're in the right place. You can always go back once you know of course. If no advance at all was better we'd all be running static timing like the old A/C bikes. If you're not going to experiment what's the point of the zeel? Dyno time really is the best way to do this.

[T.RexRacing]

For maximum output you want to see peak cylinder pressure at 10-20 (depending on set-up) degrees ATDC. Since actually measuring that requires the tooling and budget of Honda we as normal humans advance the timing until it's detonates from too much advance and then retard. The engine can survive some detonation. The hardcore racers with big budgets see X amount deto events per mile raced as spot on.

You're close on the mains even though the plugs may not look that way to you. If you leave the mains where they are and advance timing you're giving the existing charge more real time to burn. If it detonates stop and back off. I have always gotten the advance good with useable fueling and then went after the fuel curve because of the real time factor that weighs heavily on the advance curve but not fueling. I can see on the plugs you could advance the timing at high RPM w/o damage to the engine.

The dyno chart you provide tells little other than someone's bike doesn't like that much timing. The pipe may not like the timing advance but as the chart tells you they found that out by testing. I'm not advocating a whole curve advance just at the last 2000-2500 of the rev range and maybe 1 0r 2 degrees. With an adjustable ignition it's simple to change if the results are not to your liking.

Dyno time is the real answer.

I just grabbed that image from the 'net and have no comparison images. Honestly that one looks like I'd try one main leaner if it was for racing. And a degree or two of advance too. That's a really cold plug too.

[Bngt]

Yes, there is no replacement for testing and measuring. I plan to Dyno when I get the time.
My take away from the 50cc graph was that they were able to advance timing without detonation and they did get slightly higher peak but lost overrun. I might find the same with further advancing the timing, but only testing can tell.


I ran below curve, which I got from Kenny, but for the plug reading I had retarded at 10k and 11k according to below to reduce risk for detonation:
Zeeltronic
1000 18
1500 20
3000 24
4000 25
7000 25
8000 22
9000 17
10000 16->14
11000 15->11

A stock 31K is according to Borut:
2000 17
3500 27
9000 17
9900 9
11000 9

i.e. much lower at high rpm even if you do the 4 degree stator plate mod.

Borut also provided an alternative curve
2000 17
4500 29
6000 29
9000 20
12500 4.5

there is no further info or theory supplied and I haven't asked.

It seems like 25-30 at midrange off pipe (<7k) is common and then dropping off to 17-20 at 9k.

Then there is a huge difference at 10k. Should it be 9 or 16? and then at 11k should it be 9 or 15?

I can go back to Kenny's original curve but I guess I will need a dyno to tell the difference and 14 might be safer than 16.

[cookie]

If you really want to get into this and expand your thinking install some EGT gauges and start moving exhaust gas temperatures up and down with timing changes. PM'd you some of my info.

[pushstartrearset]

Are you running the stock spark plugs?

I don't see any plate burn on the ground electrode (side)...might want to try a size or two cooler plug to start to see a plate burn somewhere near the middle of it's length. One big thing i got from the manual, if you are going to do any high speed riding (and to keep from damaging the engine), run a cooler plug...or BR9ES over BR8ES plug...maybe even cooler if the plate burn isn't in the right place.

Sounds like your porting and compression are mild (going back and reading...a lot like mine on my RD400) only the squish set to optimum. I'd go w/ the stock curve and maybe like cookie said IF you have the PCDI-10V, move the whole curve a degree or two if you have too...but i would start w/ the STOCK curve...you didn't really change the port timing, so it doesn't sound that extreme, right? I don't know jack about porting, but if the timing isn't changed...

See what i mean by plate burn in this image attached.

[Bngt]

Thanks, I run BR9ES and the color shift on the side electrode is exactly in the middle of the bend so heat range is probably ok.