Wasp .28 Carb Binding

[Savage Beast]

I just upgraded to the Wasp .28 and just completed the break in. When I went to drive it for the first time, I thought it had unbelievable power! Until I realized the carb was only opening 3/4 of the way. It seems to be binding when I open the throttle up all the way. The servo-saver flexes before it opens the carb up all the way. I have to physically moved the throttle arm to get it to open. The linkage is adjusted perfectly also. The slide just doesn't seem to be very fluid or smooth. Has anyone come across this problem and what is the fix? I can't wait to see what this monster does when it hits full throttle!

 

[Digital Liquid]

I know what you are talking about. It's b/c the carb is aluminum and doesn't give much flex. You need to line up the linkages perfectly. I will post some pics in just a minute...

 

[Lessen]

:OT: servo saver on throttle? is this common? I've never run across anybody mentioning using a servo saver on the throttle.

 

[Mr T-Maxx]

fftopic: servo saver on throttle? is this common?

I was wondering the same thing Lessen, He probably meant the servo horn.


Mr T

 

[Lessen]

I was wondering the same thing Lessen, He probably meant the servo horn.


Mr T

ohh. bending maybe? I ran into a problemm like that when tuning my twins. angles of linkages was the culprit there.

Probably not a bad idea if you have a strong servo but don't have a radio with EPA

 

[Savage Beast]

Oops... servo horn is what I meant. Sorry. The throttle linkages are completely stock. This is the first time I have come across this problem. And this is after running the stock mill, a Hyper 21 8 Port, and an Outlaw .26 with the same linkages and no problems until the Wasp .28.

 

[Digital Liquid]

You are right, there is a servo saver on the throttle/brake linkage. I run with it and have no problems dropping the hammer or stopping on a dime. If I hit the brakes too hard and too quickly, it will flip, the back end will kick up and roll over the front.

Anyway, about your linkage setup. Check out the pics below:

---The first thing to do is to make sure that the throttle arm is at a perfect right angle (as seen below).

---The second thing to do it to make sure that your carb arm is lined up. Make sure the little bar is perfectly straight (as seen by the red line). If it is pointing up or down, it will create a binding issue.

---You need to also adjust the LSN position to help you line it up (as seen by the green arrow). The tip of the ball end on the LSN should be the exact same height as the carb arm.

Once you check your setup, that should solve the problem for you. If not, then let us know.

 

[Savage Beast]

That did it. The 90 degree arm needed to be reset. Thanks for the pics DL.

 

[Digital Liquid]

That did it. The 90 degree arm needed to be reset. Thanks for the pics DL.

No problem...

 

[Lessen]

not to put down your methods DL but I always like to set my horns away a little bit. I do this because of the arcing nature of the horn in movement. Because they don't allow the linkage to truly slide in and out the linkage has to move sideways a little bit. I always figured if I set the horn back beyond 90 a bit then within it's motion it will move to center then move to the opposite side. Setting up like this splits the lateral motion of the linkage to both sides rather than putting it all on one. I find that it creates a smoother movement. Is this making any sense?

 

[Digital Liquid]

Good point, Lessen. I never thought about it that way. I have no problem w/ my setup now, but if it can be improved I am always open to suggestions. I am getting ready to tear her down and put on alot of new stuff, so I will try out your suggestion. Thanks for the lesson, Lesson.

Later....

 

[Mr T-Maxx]

Wow!!!

DL, that was some good stuff!!

Incredible detail, awsome pictures, problem solved(1 hour 13 minutes). This kind of info is what makes RCNT the best forum on the web!!

Keep up the good work!

Mr T

 

[Lessen]

Good point, Lessen. I never thought about it that way. I have no problem w/ my setup now, but if it can be improved I am always open to suggestions. I am getting ready to tear her down and put on alot of new stuff, so I will try out your suggestion. Thanks for the lesson, Lesson.

Later....

it may not be something you'll notice but it's just something I always assumed was proper. :shrug: I figure if we spend such big bucks on high end servos to save a couple tenths of a second then it must help at least a little, especially at the pro level. Actually Futaba must think so also because they have incorperated an adjustability for exactly this purpose into the 3PK. It's called "Rapid Throttle Acceleration". It allows you to adjust a set point within your throttle's EPA (up to 40%) that your servo automatically "jumps" to at the very moment input changes from neutral. This is to counteract the lesser amount of motion that the linkage is left with at neutral when set up in this manner. Talk about the nitty gritty...

LMAO!

I just noticed the "Digital Liquid from your [gold member]"

HAHAHA! Great stuff!

 

[sweetdiesel]

Hey lessen is this the same as the throttle deadband adjustment on the JR radios? I have this on mine and haven't messed around with it yet.

 

[Digital Liquid]

Actually Futaba must think so also because they have incorperated an adjustability for exactly this purpose into the 3PK. It's called "Rapid Throttle Acceleration".

That is very similar to the "Throttle Punch" which is on my KO Propo radio. I use it all the time.

 

[Lessen]

Hey lessen is this the same as the throttle deadband adjustment on the JR radios? I have this on mine and haven't messed around with it yet.

I really don't know to be honest. You would think they could all at least use the same lingo... :shrug: