"the tuning bible"
#62
#63
Hi everyone ! I have a quick question ............ocassionally my engine will go way rich and flame out after refuling during a pit stop . What causes this and how can I tune my motor differently or what do I need to do to prevent it ! Thanks Dave .
#64
Generally you will have the tune go off after a pit stop because the tank was over filled! It usually only lasts for half a lap... Don't over fill the tank and problem solved... some fuel guns are set up in a way that they can't over fill due to the positioning of the vents....
#65
Generally you will have the tune go off after a pit stop because the tank was over filled! It usually only lasts for half a lap... Don't over fill the tank and problem solved... some fuel guns are set up in a way that they can't over fill due to the positioning of the vents....
#66
I should add that the reason the tune goes off when you over-fill the tank is because when you fill to the top orf the tank neck and shut the lid, the extra fuel in the neck is forced up the exhaust pressure line. This means that the exhaust doesn't have the same effect on the tank pressure till you burn off the excess fuel and the motor will go off tune quite quickly.
#67
Hi there.
What a great forum you have .
Ron Paris was a hero when it comes to glow engines. Many years ago at a EC or WC he looked at a plug for 30 minutes... Just to be sure to get the right diagnosis for his driver.. What a champ
Well.
A tank in a car should ALWAYS be filled up to the top - in a race that's quit nessesary to fill the tank 100%.
I would suggest you to lean the LSN a little. If the engine runs too lean on that setting, you could try a little hotter plug. How much nitro do you use? Hotter plugs instead of a RB#6 is RB#5 or even better a SH#7. Increase the idle speed a little. All too often drivers sets their idle speed too low. That's critical with a full tank of fuel, where the mixture gets a little rich = lower idle speed.
What a great forum you have .
Ron Paris was a hero when it comes to glow engines. Many years ago at a EC or WC he looked at a plug for 30 minutes... Just to be sure to get the right diagnosis for his driver.. What a champ
A tank in a car should ALWAYS be filled up to the top - in a race that's quit nessesary to fill the tank 100%.
I would suggest you to lean the LSN a little. If the engine runs too lean on that setting, you could try a little hotter plug. How much nitro do you use? Hotter plugs instead of a RB#6 is RB#5 or even better a SH#7. Increase the idle speed a little. All too often drivers sets their idle speed too low. That's critical with a full tank of fuel, where the mixture gets a little rich = lower idle speed.
Last edited by Lille-bror; 07-14-2009 at 12:10 PM.
#68
put a pressure chamber in the line between exhaust and fuel tank
#69
Hi M7H.
How does the pressure champer work? Do you have a link where to buy them?
Thanks
How does the pressure champer work? Do you have a link where to buy them?
Thanks
#70
How it works?
After refueling with a full tank, the pressure puls from the exhaust pipe might overload your engine, this pressure chamber then works as a booster chamber to add some volume in the system.
Sometimes the lid of a tank might have this booster volume, but this just might not be enough....
Where you can buy it?
It is from Mugen, part B0116
After refueling with a full tank, the pressure puls from the exhaust pipe might overload your engine, this pressure chamber then works as a booster chamber to add some volume in the system.
Sometimes the lid of a tank might have this booster volume, but this just might not be enough....
Where you can buy it?
It is from Mugen, part B0116
#71
Thanks M7H
#72
Whoever suggested that they might be overfilling the tank is likely correct. Most off-road tanks are sealed with an O-ring, and depending on the brand, the O-ring may be positioned partly into the filler neck of the tank. If you fill the tank to the absolute top including the filler neck, then snap the lid shut once you're finished refueling, the "plunger" effect of the O-ring forces enough fuel into the carb that it makes the engine run rich until you can clean it out. This is quite common and, as already mentioned, most fuel guns position the vent tubes about half way into the filler neck to stop filling the tank before it reaches the absolute top of the filler neck. I've never needed a pressure chamber on the exhaust pressure line because it's not an issue when you don't overfill the tank.
#73
Hi Steve.
I see your point. When I drove buggies back I the early ´90, we didn’t had that problem. But there was no O-ring putted into the neck like today. We used to fill the tank 100% and then a little bit more when we removed the filler tube – just to be sure
I hope dead1dave can use your replies.
I see your point. When I drove buggies back I the early ´90, we didn’t had that problem. But there was no O-ring putted into the neck like today. We used to fill the tank 100% and then a little bit more when we removed the filler tube – just to be sure
I hope dead1dave can use your replies.
#74
Whoever suggested that they might be overfilling the tank is likely correct. Most off-road tanks are sealed with an O-ring, and depending on the brand, the O-ring may be positioned partly into the filler neck of the tank. If you fill the tank to the absolute top including the filler neck, then snap the lid shut once you're finished refueling, the "plunger" effect of the O-ring forces enough fuel into the carb that it makes the engine run rich until you can clean it out. This is quite common and, as already mentioned, most fuel guns position the vent tubes about half way into the filler neck to stop filling the tank before it reaches the absolute top of the filler neck. I've never needed a pressure chamber on the exhaust pressure line because it's not an issue when you don't overfill the tank.
#75
Whoever suggested that they might be overfilling the tank is likely correct. Most off-road tanks are sealed with an O-ring, and depending on the brand, the O-ring may be positioned partly into the filler neck of the tank. If you fill the tank to the absolute top including the filler neck, then snap the lid shut once you're finished refueling, the "plunger" effect of the O-ring forces enough fuel into the carb that it makes the engine run rich until you can clean it out. This is quite common and, as already mentioned, most fuel guns position the vent tubes about half way into the filler neck to stop filling the tank before it reaches the absolute top of the filler neck. I've never needed a pressure chamber on the exhaust pressure line because it's not an issue when you don't overfill the tank.
learning how to tune properly will alleviate 99% of the flame out problems , listening to the engine and understanding what needs to be done to correct any problems . i know some very very fast guys that have no idea how to do this , that is what a very very good pit guy does