ESE's works engine tuner

[jasonu]

And I am sure I didn't. Quite the opposite in fact: if the tract diameter has to be small for some reason (rules), you can diminish its negative effect by making it as short as possible. And because it's a lovely day, here is my solution of making it really short.
I slip a plate (P in the drawing) around the carb. The hole in this plate is about 2 mm larger than the carb's outer diameter. Then I slip a thick O-ring O around the carb. Then I slide this composition into a hole in the disk valve cover D and fasten it with two bolts B.
Plate P compresses O-ring O which centers the carb in the disk valve cover so there is no metallic contact anywhere. With this solution I manage to fit the carb at 2 millimeters from the disk valve. It works with reed valves too.

You can play with the O-ring size and the rate of compression to vary the flexibility of the carb mounting. You can also fit a second, smaller O-ring at the bevelled end of the carb, next to the disk valve, to keep the carb from sagging when applying a light rate of compression on the large O-ring.
The ideal would be an O-ring with a sleeve. Maybe you can produce something like that with 'liquid rubber'.

That is really similar to how I mounted my RG400 flatslide to the KE125 disk bottom end. I did it more to keep the carb tucked in but if it gave me a power gain then double good.

[husaberg]

Why does all text on this page self-center? I tried overriding it with advanced editing and clicking 'align left', but to no avail. It is beginning to annoy me....

The self center may be my fault. If you quoted me. but i guess you figured that out.

[wobbly]

I discovered the 135mm inlet rule of thumb on a TM125 MX engine used for 125 class kart shifter racing .
It had a VF2 with a late model RS125 rubber manifold along with Kehin SPJ solenoid carb.
The old Dynamation sim I was using said shorter was better.
I really wanted 50 Hp and found an old model RS125 intake rubber - 20mm shorter, fitted that in a back to back,Voila more power everywhere in the useable range.
Each test is 3 pulls averaged.
That length is for a reed - the RV needs to be alot shorter again.

[Frits Overmars]

My Helmholtz Blues contained no quote at all. And neither does this post. But they get centered just the same....

[ief]

Doesn't look centered to me, browser issue?

[TZ350]

My Helmholtz Blues contained no quote at all. And neither does this post. But they get centered just the same....

Looks OK 2 me 2 .....

[TZ350]

That length is for a reed - the RV needs to be alot shorter again.

Oh no ..... ... it was hard enough to get down to 130 and EngMod2T points to 85mm

Now I will have to look at Fritz's Idea.

[Frits Overmars]

Doesn't look centered to me, browser issue?

It would seem so. With Windows 7 + Internet Explorer 8 everything gets centered. With Mozilla Firefox it doesn't, but Firefox is terribly slow; too slow to use on a regular basis. Suggestions anyone?

@TZ350: sooo sorry .

[TZ350]

@TZ350: sooo sorry .

You don't sound very sorry ... LOL ... it took me months to get it as short as it is now, but at least you have given me a way forward, otherwise I might have been a bit stuck.



Frits thanks for the idea ..... I need to get down to 85mm from RV to Bellmouth.

[ief]

It would seem so. With Windows 7 + Internet Explorer 8 everything gets centered. With Mozilla Firefox it doesn't, but Firefox is terribly slow; too slow to use on a regular basis. Suggestions anyone?

@TZ350: sooo sorry .

I'm an opera adept since like forever but that has it's quirks to here and there... I just stick with it

[F5 Dave]

Hello Frits

Thank you for the manifold idea, that is brilliant & will chop a heap off. Hope my carb now clears the cases, but that can be fixed. Thank heavens for nice days.

[Haufen]

It would seem so. With Windows 7 + Internet Explorer 8 everything gets centered. With Mozilla Firefox it doesn't, but Firefox is terribly slow; too slow to use on a regular basis. Suggestions anyone?

@TZ350: sooo sorry .

You might want to try Opera. Browsing with Internet Explorer is like driving a four-stroke (to me). I try to avoid it as often as possible.

I discovered the 135mm inlet rule of thumb on a TM125 MX engine used for 125 class kart shifter racing .
It had a VF2 with a late model RS125 rubber manifold along with Kehin SPJ solenoid carb.
The old Dynamation sim I was using said shorter was better.
I really wanted 50 Hp and founded an old model RS125 intake rubber - 20mm shorter, fitted that in a back to back,Voila more power everywhere in the useable range.
Each test is 3 pulls averaged.
That length is for a reed - the RV needs to be alot shorter again.

Did you have to rejet to achieve that result? When playing around with intake lengths on reed engines I found that the shorter length liked a smaller main jet. But then again the lengths were 190 and 165mm or thereabouts.

[Grumph]

Why does all text on this page self-center? I tried overriding it with advanced editing and clicking 'align left', but to no avail. It is beginning to annoy me....

Oh, I don't know Frits, it made the Helmoltz Blues read like a Haiku...very artistic.

It seems to be unique to this thread - and happend after a Husaberg post so I'd blame him....

[mike schmidt]

Just a dumb boat racer, but several years ago I built a new 250 Kawasaki boat engine. A pair of KX 125 cylinders on billet case. I used KX 250 reed cages and had them kicked at an angle so that the upper reed pedals were almost 90 degees to the bore centerline. Problem was that I could not fit the two Mikuni 38 flatslides on as they crashed into one another. I welded up two real nice aluminum manifolds that moved the carbs outboard, so they would fit. Modeld them after a "Pro Stock" car manifold. The motor was a dog at best. Several MPH slower than my other ones. Only change was to epoxe up the crankcase, move the reeds so that the mounitng surface was parellel to the centerline of the cylinder bore and mounted the Mikuni mount almost to the face of the reed cage. Became my best motor overnight.

About 25 years ago I did a whole bunch of KT 100 kart motors to help pay for boat stuff....We had a dyno mule motor that we expermented on. Once we found what direction helped, we then pushed the rules in that direction on the "stock" motors. One of the first things we found was that the closer you can get the carb to the cylinder, the more horsepower they made. On our "stock" motors we milled the carb mount on the cylinder to the very min. spec., faced the carb adapter to the min. spec., cut the overall length of the carb to the min. spec. and assembeled them without any gaskets (just Yamabond). We saw almost 1/2 H.P. by shorteneing the intake up about 3mm.

That said, the shorter the better is what we have found.

Fritz: I really like your "O" Ring systen. Will test on our 125 Rossi at next race.

Wayne: This message board is real neat, but until you have posted some amount of posts, you can not reply to private mail......

teammsr@comcast.net

Thanks

Michael D-1

[husaberg]

My Helmholtz Blues contained no quote at all. And neither does this post. But they get centered just the same....

I just assumed you "replied with quote" then it seems to retain the previous formatting, even if you delete the original post

It would seem so. With Windows 7 + Internet Explorer 8 everything gets centered. With Mozilla Firefox it doesn't, but Firefox is terribly slow; too slow to use on a regular basis. Suggestions anyone?

@TZ350: sooo sorry .

The only thing i use Firefox for is his thread and Explorer for everything else and yes it does seem slower for me to(.i'm Just too lazy to log in on initially on another browser though) Gee I only just found the Refresh button (Had to ask Mental)on Firefox as well, so add thick to lazy.
I did try finding the Helmoltz blues in the search part of pitlane it wouldn't work for me at all (In hindsight maybe it had to be in the first Half of the Thread?)
Does the German article you posted Frits Have any more tidbits that is not in the Pitlane thread? As German is even worse than my English.

Oh, I don't know Frits, it made the Helmoltz Blues read like a Haiku...very artistic.

It seems to be unique to this thread - and happened after a Husaberg post so I'd blame him....

Why not, Everyone else is my fault. Just ask My lady, she has a list and all.