Kane-o

iTrader: (12)

Hi All,

Today I had a runaway when the carb on my Werks B5 Pro stuck wide open in my Losi 8ight T 3.0. It was after a large triple and I believe the culprit may be the carb was not tight enough and twisted a small amount causing it to bind. Although to get it to close from the position in the picture, I had to take the motor out of the truggy and tap it assertively with some pliers.

On that note:

1) Has anyone had the carb stick like this in a Werks?
2) How tight should the screw be tightened that grips the carb assembly?

Thanks for your help.

-Kane

buchanan88

iTrader: (6)

Make sure your EPA is set correctly after you ensure your carb is tight and linkage isnt in any kind of bind. You dont want to pull the slide out any further then the carb insert.

Kane-o

iTrader: (12)

Yes, the EPA is fine. It doesn't pull past the carb insert.

Thanks,
Kane

Jerm13

iTrader: (36)

I have run Werks for a while and have only had 2 issues, both of which were caused by me.

1. I tightened the set screw down too much and warped the slide cylinder. This caused the carb not to close fully.

2. I was adjusting the idle and screwed it in too far and gouged the slide. This made it very difficult to move it in and out. I ened up pulling it apart, buffed it down and it was fine.

I would take the link off the servo and see if it moves freely. If it does, your servo or set-up is bad. If it is still lock at WOT, you have something in there causing it. Pull the boot off the carb and spray it clean. Then back off the idle adjust screw and see if that helps.

If it is still locked, you may have over pulled the slide. You can try and force it back in ( take the carb off the motor) by pushing it in and wiggling it side to side and trying to rotate it a little to see if it will go back together.

Nice job. Keep us informed.

mr240

iTrader: (61)

Are you running a throttle return band or spring.

Kane-o

iTrader: (12)

Thank you for the info. I will take the carb apart tomorrow and see if there are any issues. It is pushed back in and functioning, but I want to see if something is up so it doesn't happen again.

Jerm13

iTrader: (36)

I suggest running a return device, wether its a spring or rubber band. They work wonders. Just stiff enough to pull it closed in a hurry but easy enouogh it doesnt make the servo struggle.

shanef

iTrader: (38)

I'm nearly 100% certain you will have a bent idle screw. Major weak point in the Werks/Orion carbs. If Werks/Orion didn't have their heads in the sand, this issue would have been fixed years ago.

curacing2

A good knock to the slide can damage the groove that the idle screw sits in since it's alloy and the screw is steel, you should be able to clean it up with a fine file if that's what it is.

shanef, have you bent an idle screw?..I would not have expected them to be that soft.

Bill8Truggy

iTrader: (3)

I would check your EPA again. If it was correctly set, the slide would not be pulled to full extension.

When the slide was pulled to full reach, it may have misaligned (more of the slide hanging out of the carb than left in) - and because of the misalignment, the slide locked in position.

I dare say when it was misaligned, if you moved the slide to one side or the other, it would have popped back into position, and slid back in without the need or percussive force.

I personally have not had a problem with the carb slide on my B5's (8ight T) – But I set the EPA to only open the slide as far as to clear the restrictor – the slide is never pulled to full extension.

shanef

iTrader: (38)

I have at least a dozen werks/orion carbs in the shed all with bent idle screws and they are not all from me either!

It's either an issue with the screw, or it's in the barrel/carb design/tolerances.

Kane-o

iTrader: (12)

The EPA was set correctly. A slow or fast pull of the throttle would pull the carb open just short of the Venturi.

I did try to manipulate the carb to return it back to te closed position, but this was unsuccessful and a WACK was needed.

I will check out the idle are today.

Thanks guys.

Werks

iTrader: (3)

If you have a dozen of our carbs laying around with bent idle screws then you should probably know that the only way to bend an idles stop screw is by having the carb linkage not set up correctly. The tip of the idle stop screw is only about 2mm thick and you can only make steel to a certain strength. Nowadays servo's are incredibly strong commonly putting out at least 120oz/in or more of torque. Most people have seen that it is enough torque to easily bow your chassis if your linkage is set incorrectly. So if your throttle linkage is set up incorrectly with the linkage pulling on the slide at an angle because the snap ball on the end of the slide is in the incorrect position or the linkage is not aligned properly when the slide is pulled out the linkage will attempt to rotate the slide in the carb body.

Now imagine all of the force of the servo pulling on that slide trying to turn it and the only thing stopping it from happening is the tip of your small idle stop screw that runs in a groove machined in the slide. As you can probably imagine after this happening hundreds of times per lap again and again and again after a while something will eventually give and most often it's the tip of the idle screw. If that was not the weak point the user would bend the slide and an idle stop screw costs a hell of a lot less to replace than the slide. The issue though again stems from the fact that the linkage is not set up correctly not that the idle stop screw which is made of some type of soft steel lol. The servo is just so strong that because the linkage is not set up properly to pull on the slide straight it is applying enough force on a 2mm thick piece of steel to cause it to bend, and that takes a lot of force!

Werks

iTrader: (3)

Kane-o, sorry to hear about the issue that you experienced. Here is what I would do, take the idle stop screw out completely. This will then allow you to remove the slide. To do that just pull it out completely until the rubber carb boot is fully extended. There is a lip on the inside of the boot that fits into a groove in the carb body, so just pull on the side of the rubber boot by the carb to stretch it a little so that you can pull it out of the groove and the entire slide will come out. Once you get it out inspect the tip of the idle stop screw to see if it is bent or if there are any burrs/gouges worn into it. If not then the idle stop screw can be re-used. Take a look at the slide and on it you will notice a groove machined in it. This is where the idle stop screw fit into. Take a x-acto knife held at a 45 degree angle and run it up and down the edge of the groove to clean off any burrs that might have been caused by rubbing against the idle stop screw. Once you have done that spray off the slide and idle stop screw with some carb cleaner.

Now to re-install everything start off by putting a drop of after run oil on the slide and idle stop groove and put the slide back into the carb (leave the idle stop screw out). Re-connect your throttle linkage and turn the radio on. Now go through the basic verification process that you linkage is set up properly which quite frankly everyone should be doing anyways any time you either build a new car or change the servo/engine.

Slowly squeeze the throttle and watch the slide movement. If the slide starts to rotate when it is being pulled out then your linkage is not lined up correctly. You can adjust this by rotating the snap ball position on the end of the slide and/or by rotating the entire carb body by loosening the carb pinch bolt. Adjust everything so that the slide is pulled out straight and it does not rotate. Once you have that done put the idle stop screw back in and double check your end point adjustments and linkage to make sure that it is not trying to force the slide back further than the stop point when the brakes are applied. As I mentioned the above set up stuff is something that should be done any time you build a new car for the first time or you switch engines/servo's. Once you start doing those basic steps to confirm that your set up is correct you will never, ever have a problem like that again be it with one of our engines or another brand. Hope this helps, if you need any more help please feel free to PM me

Kane-o

iTrader: (12)

Thank you for taking the time for a detailed response. The Losi is tricky in that you have to get creative with the carb and throttle ball alignment because the centre diff gets in the way. I did have everything aligned correctly although like I said the carb assembly may have twisted which would have caused problems.

On that note, what cutoff point to you guys use to know when you have tightened the pinch bolt enough on the carb body?

Thanks,
Kane