ESE's works engine tuner

[husaberg]

I do not think this is the reason today, even when many parts and tolerances are involved.

For older days you may be right ��

Diffrent bikes differ todoy only about 0,1 to 0,2 mm in serial gap these days...

Specially with undomed piston so so easy to measurue in production..to be save...

Grüße Wolfgang

Those 7 components plus stoke differences add to .8mm if its only .1mm per component.
The Japanese are masters and constructive laziness and only do stuff by hand using labour if it really matters to selling the product, measuring squish takes time if all the other manufacturers don't bother, thus they are all basically all hindered the same. So no potential gain for the additional labour inputs, so no real motivation to do it.
I cant remember exactly how but the Cranks gaps in mass-produced engines used to be measured with compressed air leakage rather than direct or indirect measurements or plastiguage or mics etc as it could be done in situ with air.
Honda C50 have 32 spokes as it was worked out it would save $1 a bike #note They have built 100 million of them.
Alloy frames used to be tig on the visible outside and mig in the bits you can't normally see.They don't always get stuff right, like not line boring cams in the 80's they thought their tight production tolerances would make it unnecessary as it had worked with cars.

[dutchpower]

125 sx 2023 ecu

Requested engine load

[Wos]

[QUOTE=husaberg;1131217587]Those 7 components plus stoke differences add to .8mm if its only .1mm per component.
[/QUOTE

Thanks for the Look inside japanese strategies 😯

I dont know the tolerances of japanese bike builders.

0.1 mm in japan? This is very huge? 😥

As a mechanic cant beliefe that husa✋

Should i better by a minarelli next...🤔

Grüße Wolfgang

[RomeuPT]

Hello

Does anybody know what is the standard thickness of vforce 2 reeds for CR 125? probably the same for other 125 motocross!?

I bought a replacement and it has 0.35, and the ones I had 0.4mm.

Not sure if I noted any difference in the power, no flutuation at high end and higher idle at least I felt.

Thanks

[koenich]

125 sx 2023 ecu

Requested engine load

Thanks Dutch! So which is the controlling factor to change injection mass flow?

[HSuomi]

Hello,

Decided to create account here as I have some problems with methanol and this forum has a lot of experience about it.

I have old air cooled Suzuki DS80 engine that im running with VP fuels M5 methanol. It works quite well and makes 12% more power than with 98 petrol. But problem is that after dyno- or top speed pull when you perss clutch it keeps reving insanely high for few seconds even the throttle is closed.
It must be killed with engine braking and brakes. Its even detonating after top speed test if clutch is pressed and needs a long engine braking. I've had bit similar problem with petrol but not even nearly so bad and it ends quickly.

Carb is chinese PWK 26mm with #32 idle jet and #220 main jet. Needle jet and needle are from bigger PWK. Needle is shortened to suit 26mm carb and randomly grinded with drill and sandpaper. It has electric fuel pump from K&N and needle valve flows 6,6dl/min. Engine has around 19whp with short dyno test.

What is the mechanism behind this behavior and any suggestions how to get rid of that?

Here is a little video, unfortunately first pull is missing where problem was worst. Second pull still has some and third for some reason is not so bad on this test. https://youtu.be/j8PJIAayKUU

[Pursang]

Carb is chinese PWK 26mm with #32 idle jet and #220 main jet. Needle jet and needle are from bigger PWK.
Needle is shortened to suit 26mm carb and randomly grinded with drill and sandpaper.

It has electric fuel pump from K&N and needle valve flows 6,6dl/min.

Electric fuel pump produces 4-7 psi. This is way more than the gravity head in a motorcycle fuel tank.

Perhaps the float valve is unable to resist inflow from flat out to suddenly zero. Fuel level rises and pilot system over delivers.

Rather than pressurise the carby, use the pump to feed a header tank with an overflow back to the pump supply.

[HSuomi]

Electric fuel pump produces 4-7 psi. This is way more than the gravity head in a motorcycle fuel tank.

Perhaps the float valve is unable to resist inflow from flat out to suddenly zero. Fuel level rises and pilot system over delivers.

Rather than pressurise the carby, use the pump to feed a header tank with an overflow back to the pump supply.

It has Y-branch and return line to fueltank with little flow restrictor. At least the carb is not overflowing.

[TZ350]

But problem is that after dyno- or top speed pull when you press clutch it keeps reving insanely high for few seconds even the throttle is closed.

What is the mechanism behind this behavior and any suggestions how to get rid of that?

"reeving insanely" is a very familiar problem for me with my two strokes and Methanol.

I think it is due to being a little lean or maybe being exactly on the correct Air/Fuel ratio and Methanol's predilection to auto ignition (which is different to detonation). 5-10% Acetone is said to reduce the tendency of Methanol to auto ignite. Auto ignition can induce detonation, so you can have patches in the rpm range where one or both are happening.

[wobbly]

I have two questions that may point to what is happening.
First , what is the actual float valve orifice size.
Second , if you are using a pump with a return and a jet restriction back to the tank , put a T in the fuel line next to the carb inlet , and run a clear fuel line upwards say 2M off this T.
Start the pump and rev up the engine.
What is the pressure height of the fuel in the clear line above the gasket face of the carb bowl , when the engine is reved.

[TZ350]

Petrol Methanol setup. Remote Methanol chamber has a clear hose against the side of the carburetor float bowl so that the Meth fuel level can be seen and adjusted.

I am looking forward to trying this.

[dutchpower]

Thanks Dutch! So which is the controlling factor to change injection mass flow?

AFR and EGT

[diesel pig]

AFR? I know what EGT means I even have some gauges to measure it but AFR? and google is not helping.

[pete376403]

AFR? I know what EGT means I even have some gauges to measure it but AFR? and google is not helping.

air fuel ratio

[jonny quest]

Methanol post... did you try a surface gap plug?