jato 3.3 bogging

[jato3.3 4 life]

Hello all,
i recently bought a jato 3.3 used. It was running not great but ok. i took it to my local hobby shop (hobbytown usa) and the guy there tuned it and it was running amazing. id never seen it do wheelies before :P. The day after that i went to run it and it was bogging down a little but not to bad. It was running anything like it was at the hobby shop. So the day after that i took it to a local dirt track. I couldnt keep it running! It would bog down so bad out of the corners. This is my first nitro and i dont know anything about them. I didnt think it could be as easy as a tuning issue because it was just tuned? Sorry for the long read any and all help would be much appreciated.

[Assassin]

Watch the Traxxas Tuning videos. The engine needs tweaking for changes in temp humidity, elevation, fuel, plug, tuned pipe, header length, etc. Usually the carb can hold a tune unless those factors change greatly. Either way you should become familiar with your engine and how to tune it.

If you mean she bogs as in farty, smokey slow, & rpms fall too low to stay lit its rich.

Somehow though, I think you may be a tad lean. I think she cuts out at various engine speeds abruptly. In that case richen up the HSN and then re-tune the HSN when the engine is at operating temp.

[Jato8283]

The best I can offer is go back to hobbytown and ask the guy to explain what he did. He should help you, since youll more than likely be buying all your parts through him. Tell him your problem. Explain it in as much detail as possible. Your engine may be going out the door since you really have no idea how well it was taken care of since you bought it used.

Ps - Trust me, once you fix your problem you will have no desire for another car, cause no other car can stand up to the power that is J.A.T.O.

[jato3.3 4 life]

I took it out again today and it still was bogging out of the corners. i messed with the tuning and nothing seems to help.

[Assassin]

You need to provide more clear details. Messed with the tuning and boging down doesn't say much.

What did you try uot when tuning, plus how and when does t bogg down?

What do you mean by "bog" exactly? Cuts out abruptly, or rpms fall too low and it stalls? You need to be clear if you expect any real help.

[jato3.3 4 life]

it wont ital for more that 20 sec before the rpms fall and it stalls. i tried leaning the hpn and the lsn i didnt do anything with the ital because when i took it to the hobby shop he did it there i didnt think that was the problem. when you first give it throttle sometimes it will just sip there with the rpms low. then once it gets going it takes off real slow blowing alot of smoke. im not sure what other details are needed. o yea once it gets going it runs ok at best.

[Assassin]

Sounds rich, and maybe the linkages are un-aligned.

pop off the air filter and look at your idle gap. If it closes any further when you tap the brake the linkage needs to be adjusted so it doesnt move at all when going from neutral to applying the brakes. At the same time make sure you gap opens as soon as you apply throttle, and it opens all the way.

Adjust the idle screw so at its most closed point its stays open .7 to 1mm

Make a 1/8 clockwise turn on both the LSN & HSN, get her warmed up & if your rpm fall too much at idle at this point lean the LSN, if your rpm climb high at idle richen it up, do this until you can idle steady, then do the pinch test.

Pinch test

Pinch the fuel line about 2.5in from the carb until the engine cuts.

If it climes high rpm and sounds like its leaning out alot, before it cuts, this means the LSN is rich.

If it quickly cuts out without climbing any rpm the LSN is lean.

We want the rpm to raise slightly and then cut out. Adjust until you get this result from the test.

If your rich on the LSN, make 1/8 clockwise adjustments until you idle a little high after a pass and the idle stays there. At this point use the ISN to lower the idle speed with 1/16 counter clockwise adjustnents. Do not close the gap smaller then .7mm.

If your lean, richen up the LSN with 1/8 counter clockwise adjustments until your rpm fall and near stall at idle, then make 1/16 clockwise adjustments to the ISN.

When you have your idle speed pass the pinch test you should be able to idle for a few min at least. Now you make full speed passes making sure you see smoke all the way to top speed. Keep leaning out the HSN as long as you see smoke to top speed and performance improves. Smoke gets too little, or performance gets less smooth, dial it back a touch until your performance is good, plus smooth with smoke to top speed. That should do it for the HSN.

At this point you can further fine tune the LSN with extremely slight adjustnents at a time, leaning it out as long as performance improves and your idle stays low. You don't want your idle gap smaller then .7mm so it has to stay rich enough to keep the rpm low at idle, just high enough to stay lit.

Remember to make a few passes after each adjustment to get the change fully into effect.

Good luck. The Traxxas Video & HPI videos should help.