ESE's works engine tuner

[F5 Dave]

Attachment 267323

Here you go ..... Freds Manx.

That really is fantastic, spoke nipples & everything. Though there has been some damage on the rear shock springs, presumably where someone picked it up.

[FastFred]

there has been some damage on the rear shock springs, presumably where someone picked it up .

Rough Bastards

[diesel pig]

- a WELL EXECUTED full house 14,000 rpm engine with 32 RWHp and a 4000 wide powerband when used to its potential, is a forgone conclusion.
Why would this sport be different than EVERY other where a 2T has been well developed - fast and reliable.


*We had electronic powerjets on the TZ racebikes over 20 years ago,Honda gave in finally in 1998,no one in buckets has one yet????
.

When you say 14,000rpm engine do you mean that is where max power would be made OR do you mean useful power starting at 10,000rpm with max power between 12,000rpm and 13,000rpm and a overev of 1000rpm or so to 14,000rpm? I am sorry if this is obvious to you Wobbly but I am abit slow if you hadn't pointed out what I was doing wrong with the keihin mainjet and powerjets I would problely still be trying to sort it!

*My igntech showed on the computer that the electronic powerjet was working when I rev up the bucket the other night so there is a bucket with a electronic powerjet in NZ Wobbley.

[2T Institute]

No problem changing up through the gears i.e. no problem when the throttle is closed for fraction of a second (Im that quick on the change). The problem is when the throttle is completely closed for a couple seconds after revving out such as when braking, if you then blip the throttle when changing down through the gears its as if there is no spark and then when you hammer it back open nothing happens again as if theres no spark, delay, then it hits and its off again. My uneducated guess is that the crankcase pressure drops so much that the exhaust gases travel into the transfer ducts and theres a delay while things equalise and burnt gases are flushed out, part of the reasoning being that this doesnt happen at lower revs i.e. if I only rev to say 10k I can shut the throttle for a couple of seconds and when opened it picks up immediately.

Don't shut the throttle Sounds more like a combination of carburation and ignition, most help would be the TPS, do you have a tacho? What rpm is it happening? How high is the idle set at?

For iphone owners check out 'Harry's Lap timer' impressive stuff.

[TZ350]

This is a 38 electric power jet carb I tried a while ago on the dyno. It has a 24mm venture fitted behind the slide and flowed well on the bench but did not make any more power on the dyno.

I figured the hold up must have been some place else in the engine and it also would flat spot if opened to quickly and in the end after a lot of dyno time I figured a taper bored OKO would be a better all round carb.

But I liked the electric PJ so the next mission is to fit a electronic power jet to the OKO.

[F5 Dave]

I went for the PWK KX carb to get the soil PJ but have to remote the TPS as the Mik one pictured would have clashed with the shock. I'll fit it in stage 2 but needs the ignitech fitted at same time or just prior.

I have thought about doing a mod Soil onto older carb (ie my 32 Mik VJ21 carb) which might be the go for Kart tracks.

[wobbly]

Useable power around 9,000 with peak around 13.000 and will rev to 14,000 without falling off the cliff.

[TZ350]

Useable power around 9,000 with peak around 13.000 and will rev to 14,000 without falling off the cliff.

Not quite 9 to 14 but getting there, an electric PJ and a bit of ignition fiddling might strech it out more.

[richban]

Not quite 9 to 14 but getting there, an electric PJ and a bit of ignition fiddling might strech it out more.

Bloody hell. OK stop now, its not fare.

[Yow Ling]

Bloody hell. OK stop now, its not fare.

Just get an old GP125, soon they will be the new FXR

[richban]

Just get an old GP125, soon they will be the new FXR

Yeah nah can't do it. Plenty of development to do on the FXR. If i went 2 stroke my sponsor would beat me up and cut off all factory support. Be like going from a protype ride down to CRT. Anyway the new engine will smoke that for sure.

[TZ350]

Found out my inlet manifold went downwards just a bit and the other half upwards just a bit, so at low throttle openings with too weak suction from the engine I had like a little puddle in the inlet manifold. As soon as I opened the throttle, all of that mixture got pulled in at once causing a very rich condition. Your problem sounds like something similar,

There is a hollow in there that collects a lot of oily mixture that could be evidence of something similar to the puddle you describe.

[richban]

Stumbled onto this guy today. Amazing bike build. No need to speak the language just start from the beginning and look at the pics.

http://www.2t-special.it/forum/viewt...498&start=1310

[husaberg]

The wife mentioned he was getting excited, glad it was entertaining.
We had a bit of a shocking start to race day with the bike and I having a number of disagreements, stalling on the line was all me though . Thankfully my prediction that we'd got all the bad luck out of the way was correct and things went better for the points races. TZ had installed a TPS, altered the ignition curve to 3D map, installed the deto regulator and set a soft and hard rev limiter, all of which seemed to be working well as there were no mechanical issues and the bike was still clearly the quickest thing on track. Theres still an issue with a delay coming back onto the throttle but Im sure we can sort this out. Chassis wise we installed a new shock Friday night which worked out really well, even with my that looks about right approach to setting preload and dampening the handling improved immensely.
First race went well with a good start and managing to get through traffic reasonably quickly, as is often the case luck played a part in finishing 3rd but with that said second was a real chance with just a .9 sec gap separating us.
Second race and the start was a shocker (thought I'd got to terms with getting off the line but more practice required), by the time I got through to 5th the front 3 were long gone so just settled in behind the 4th place rider and played it safe, passing with 2 laps to go to finish 4th. The bike and I probably could have gone as much as 2 seconds a lap quicker but there seemed little point.
I was hoping to have my new bike ready for the next round but TZ's GP125 is getting so good I might try for a ride next round as well.

No problem changing up through the gears i.e. no problem when the throttle is closed for fraction of a second (Im that quick on the change). The problem is when the throttle is completely closed for a couple seconds after revving out such as when braking, if you then blip the throttle when changing down through the gears its as if there is no spark and then when you hammer it back open nothing happens again as if theres no spark, delay, then it hits and its off again. My uneducated guess is that the crankcase pressure drops so much that the exhaust gases travel into the transfer ducts and theres a delay while things equalise and burnt gases are flushed out, part of the reasoning being that this doesnt happen at lower revs i.e. if I only rev to say 10k I can shut the throttle for a couple of seconds and when opened it picks up immediately.

This suggests to me that the low end carburation is not the problem, and the problem is someplace else like a crankcase full of exhaust gas or loaded up from an over rich power jet. The simplist thing to try next is an electronic PJ.

Anyone with any thoughts on other possibilities...

Its a bit left field but as it 's overrun the simple as suggested is overly rich condition, and then it clears
But i see you said about how TZ has just set the rev limiter .
So could this be contributing to the problem as on overrun it will likely be shutting off the spark and not therefor the engine wouldn't be clearing the unburnt fuel? well maybe?

Not applicable to your problem much but i have suffered a far worse condition on a pumper carb equipped MB100 sure it was a rocket in the straight line yet unriddle out of a harpin's.
As the pumper carb pumps fuel regards as long as the engines turning the results were a best a large delay and stutter power then coming in rather abrupt or at worst power Bog then power in with bang and high-side. It can be cured on an old pumper with mods described by Jenning from his work with the Kawasaki disk twin McCollochs. I guess its not a problem with the Karts as the throttle is barely ever off. The fuel injected Cagiva allegedly suffered from the same problem as it kept on pumping fuel on overrun as well from what i have read about it.

[Haufen]

Actually come to think of it, like yours did, there is a place in our inlet manifold that a puddle can form and I often see a lot of oil collected there. Also Dave D told us he had a similar problem coming back onto the throttle, for him it was an over rich low end carburetor setting that was loading his motor up.

So a temporary over richness might very well be the problem. Thanks for the idea.

There is a hollow in there that collects a lot of oily mixture that could be evidence of something similar to the puddle you describe.

I've got another idea also. I assume you were cornering when off the throttle. So it could be the float (whose level might be a bit lower after reving hard) that falls open when leaning into the corner and thus flooding the engine.