Carb cleaning.

[alhope34]

Well, to start I have a Tamiya Nitrage 5.2 I just bought yesterday, my first nitro vehicle. Today I accidentally completely flooded my engine to the point where the starter couldn't turn it. I was working on it standing it up with a full tank of gas...nub mistake, I know. Anyway, I removed the glow plug and put the starter on it till it didn't spit up any more fuel. It started fine and ran really sluggish for a couple tanks of fuel, but now I find my throttle is getting really sticky and will take a while to respond and will actually get stuck partially open if i don't hit the brake for a good 3-4 seconds. I'm thinking this is because of all the fuel that got in the carb just sitting there.

I have a can of throttle body cleaner I use for my car, is it alright to clean the carb out with a little bit of this then put the starter on the engine for a little while to clear it all out? Would this harm my carb/engine? If I shouldn't use this, how do you guys suggest I clean it out so it isn't sticky/sluggish anymore?

 

[JessF]

Is the throttle return spring broken or perhaps not attached? Should be a tension spring with one end connected to the carb slide and the other end connected to a fixed point, often the base of the high speed needle.

You may also have a trim issue with the throttle servo. Best thing to do is check that the servo can go from full brake to wide-open-throttle. Once you have it at WOT pull lightly on the carb slide to see if it can open any further, make sure the servo pulls the carb out completely at WOT. Do the same check at full brake, the carb should be fully closed and resting against the idle screw and not binding.

If you have to, pull off the air intake and squirt some WD-40 into the carb and slide the carb in and out by hand, NOT while the engine is running, of course.

be careful when putting liquids in your carb or engine that aren't necessarily designed for use in RC nitro engines. Although I your throttle body cleaner works fine on a full sized car, I’d avoid using on a nitro engine where small air leaks are silent killers.

I still don’t think using WD-40 where rubber/silicone seals are present is a good idea, Traxxas and other manufacturers recommend using it in the engine during the after-run procedure. Others on the forum use denatured alcohol to clean various parts in their engines. You’ll need to pull the carb off to clean with DA and let it dry thoroughly before reinstalling.

factory settings of high and low speed needles, carb alignment, trim adjustments, are rarely on the money when you go to start up for the first time. I've made it a habit to completely review these areas, the servos trim and end point adjustments, before starting the engine for the first time.

hope that helps

 

[Rolex]

Again, Jess, all excellent advise. Thanks.
I would also like to add that the car is new and the carb settings are rich. Sometimes they are too rich to run. Lean the LSN 1/8 of a turn and do the same with the HSN. Continue with the recommended break in.
Don't rush it, and don't be looking for performance for a while.

 

[Scrogg]

Remove the carb ball link and slide the boot off. wipe it all down good with the cleaner of your preference. Apply some high temp grease to the carb slide and reinstall the boot and ball link. If you are using AA batteries in the truck, that could be an issue as well. Buy a 5 cell rechargeable receiver pack. It will pay for it's self in the long run, plus the servos will perform better. If you do have a rechargeable rx pack make sure it is charged good. If the pack does not get good and warm, it's not charged fully.

 

[alhope34]

Thanks for all the advise. I am 100% sure the throttle servo is set correctly and all. I have already had to replace it today as a result from running my car into a pole (along with a bunch of front suspension parts!). The springs are fine, everything is good. Even when the throttle linkage is off the servo, I find there is a lot of resistance to push and pull it to open and close it.

I have already broke in the engine yesterday using the recommended method in the owner's manual, and I looked up videos on youtube about how to properly tune it. This engine doesn't have the low and high speed needles, there's just one. I've already leaned it out a lot from factory settings. I get blue smoke on full throttle and a little bit of unburnt fuel coming out the exhaust like recommended, and it goes like stink! I almost finished off my first gallon of fuel after only 36 hours of owning it. This 5.2 really eats up the fuel.

 

[alhope34]

Well, I ended up using a tiny spray of the throttle body cleaner last night, worked really well. I let it sit overnight, the cleaner evaporates pretty quickly anyway because it is mostly alcohol. Put in some new remote and receiver batteries today, bought a front brake and installed it, tuned everything again. Runs amazing now!

 

[Rolex]

That's good to hear.
Just remember, that pole is still there.

 

[alhope34]

That's good to hear.
Just remember, that pole is still there.

Yea... I go to a different area now, haha.