My lightened flywheel's diameter measured at 118mm OD IIRC

 

Ahh but I have had the 40mm on the bike, and I know how it performed and I've reported as such. Anyone else's past IC experience does not apply if they haven't tried the same carb on the same engine.

I've already said it's as good in the low end as the 36 for all intents and purposes. Any other guesses are just conjecture based on the fear that the 40 is such a big number and OMG it's scaring you into believing it's falling on its face/unusable etc.

Why do you fret over it? If it doesn't apply to your type of riding then just go on to the next thread. This thread isn't about "if" it will work. It is working, and very very well. The .2 sec slower 0-60 ET for the 40 I noted could be spot on, or it could closer or farther away a tenth.

The 40's chance of outperforming the 36 at 250cc was probably doomed to be limited from the beginning. But there are plenty of bigger bore KLX250s out there, and now it's known the engine will carburate perfectly with the 40mm.

Now you know that (so far) the 40s not any better @ 250cc. If you don't plan a big overbore, then the 36 is probably big enough. BB makes what 34hp? with a 33/34 carb-so go chide the 36ers about how their carb is too big.

Now everyone knows that if you have or do plan an overbore, this 40mm does start, idle, and run at all speeds very well-perfect for that matter. It could be a serious contender for 331 and up big bores.

This thread's about timing. If you want to labor over carb theory in the face of actual testing then you are encouraged to start your own thread-as most people do.


The only two "camps" I see here are the vast and mostly silent Old Guard vs the Avant Garde.

 

Well..."No one's tried it, so it can't succeed" is kind of flat Earth thinking isn't it? I mean that was the argument way back when.

It's jolly fun testing this and that, and maybe with a mod to it, the 40 can outperform the 36 at 250cc. -Or maybe not


Speaking of quotes from famous people.. Henry Ford said, "Whether you think you can, or think you cannot-you are correct!"


Presently I am psyching myself up to do the MCM which I plan to be the very next thing before sorting through any of the many variations at hand.

It's time and long overdue

 

Or is it "maybe" I'll do the MCM?


Back in 2011 Marcelino had this to say on TT:

The 5 HP gain was a combination of air filter lid removed , exhaust mod and cam mod over a completly stock EFI bike . On a bike that has already been modded at the air filter and exhaust level the gains will be smaller. You have probably gained allready 3 HP.

On a carburated bike the results will vary greatly based on your ability to correctly retune the carb .

The most significant gains are in the midrange ( 5000 - 8000 ) RPM , the rev range one uses the most on a trail bike .

If you are looking for top range power ( 8000 - 10500 ) leave the cams as they are and change the following in no particular order but all of them :

Larger diameter carb : 37 - 39 - 41 mm carb.

Higher max advance igniter or ECU ( your signature doesn't say if you have a carb or FI bike )

Aftermarket higher duration cams ( at least 290* at 0 lift or 240* at 1mm lift )

Reshape the intake duct , before and after the the carb/throtle body .

Higher compression piston .


I'll probably go ahead and do it just for the zen of it. I guess I can always undo the MCM if need be

 

Richard, you will need to feel the MCM's power. With the correct AFR @ WOT , you get a large broad trq curve that does not fall off - it tapers off gently.

 

Carb stuff stepped in the supposed discussion in your first few posts.

So full of one's self that you actually believe what you are doing has not been tried before and that everyone has nothing to contribute... I see, looks like a smidgen of messiah complex. You jeer the lack of comments, but when someone does and they do not see things your way they are subject to your ridicule. Why would anyone want to contribute.

Sorry only see one here willing to kiss your ring.

When you come up with a new idea remember what has been said so many times before... "nothing is new under the sun." As I said, tuners world wide both with and without big budgets, equipment, and time have done what you are doing. They've been doing it for years, decades in some cases.

Oh, and for my having nothing of any value to contribute to any of your conversations on my part, where did you come across Thunder Products? You made fun of their quad flow, what changed?

Oops, forgot... no questioning, comments, dissent, or contributions wanted or appreciated unless following the party lines. My bad.

 

Fusion powered ego, Energizer bunny persistence - gotta love that..

 

Troll (Internet) - Wikipedia, the free encyclopedia

In Internet slang, a troll (/ˈtroʊl/, /ˈtrɒl/) is a person who sows discord on the Internet by starting arguments or upsetting people,[1] by posting inflammatory,[2] extraneous, or off-topic messages in an online community (such as a newsgroup, forum, chat room, or blog) with the deliberate intent of provoking readers into an emotional response[3] or of otherwise disrupting normal on-topic discussion..

 

Well I guess I jumped right into the timing mod with both barrels, as both the stock and lightened flywheels are now welded up with a 3mm nose extension.



I put the lighter one on today after shaping the welded part to size-it looks much better than the first flywheel btw. The bike ran so well through the gears the other day with the stock weight flywheel and 3mm timing addition using the little 34mm carb, that I just lost my head I guess and had the 2nd one done..

So that may be about it for me on the timing. I've looked at the bracket that holds the pickup and can't really tell if it can be sliced horizontally, then rewelded with one half 3mm off to the side, OR if that would even be what you'd want to do to the bracket to move the pick up coil.

Just a guess. The bracket is $3 so it wouldn't cost much for someone to get one and have a look see.

 

Give him a break...He is an Educator.