2 speed tranny question

[Cupooterluvr]

When is my tranny supposed to switch gears, and how does it work exactly? My buggy is brand new so I don't know anything about it other than the basics. From what I've seen so far, it should be able to go about 50-60 something mph.

 

[Monkey Wrench]

If it's a true buggy, it won't switch gears because it doesn't have a two-speed transmission. What kind of RC do you have, that'll help.

 

[Cupooterluvr]

http://exceedrc.com/51c06.html

that's the website, but i don't know how to upload pics direct from my comp.

 

[HeartBreak]

It's a buggy alright.

However, it's a non-standard design. Most buggies of that "form" are usually 1/8th scale and single speed (hence the bigger cost), and usually come with a .21 and up sized engine.

That being said, have you completed break in? If you have, and have started to adjust the motor, it might not shift until it begins to get to peak rpm's.

Also, your manual (if it came with one) should list the stock settings for the two speeds' adjustment.

Good luck!

 

[Cupooterluvr]

The company I got mine from I think is a german company or some other language, because the manual was translated (badly) from some other language. So, no, it does not list the settings. I think I might have gotten into 2 gear the other day, but it could have been air in the fuel line. Which way do I turn the screw on the gears to make it shift at a lower speed? I know it may seem strange, but so am I, so I think it sounds cool when it shifts. (lol)

Yes, I have completed, or at least mostly, the break in process (running at idle for 5 tanks, then driving slowly for another 5, then medium speeds and so on is what I did, with help from my nitro expert neighbor) but it could also be that I need to re-tune the engine. The manual is not very clear as to which way to turn the high end and idle screws in order to make it lean/rich.

That said, can you also give me advice on which way to turn the screw? Right now, it idles smoothly (well, if it's supposed to sound like an idling weed eater) for about 10 or so seconds but stalls after that, is it supposed to idle for a while or is it normal to stall in idle? After going full speed, it does not stall (usually, occasionally it might stall at the exact opposite end of the street from me :sneaky: ). Also, I have to slightly trim open the throttle to start it, is this normal, the throttle is set with about .7 mm of air space when closed so I might need to open it a bit.

Wow, long post, huh?

 

[Cupooterluvr]

I also forgot to mention that I have to put it on a box to start it, so that the wheels spin freely, and I also cannot hit the brakes at low speeds because it will stall. I think it may be running fast enough to always engage the clutch, so that braking it will snag the engine also.

Another thing is, when I'm running it at just over idle to about 1/4 top speed, it switches between high and low tones (indicating high/low rpm?) but stays at the same speed. Is this normal? Once again, my neighbor says it is air in the fuel line, but that would make it go faster/slower at the diff. tones.

I can't tell if it's too lean/rich, other than the time the fuel tank lasts. The times I run it at middle to top speeds, the tank lasts about 15-20 mins, at lower end runs about 30.

Is this normal? How long does the tank normally last on your better tuned vehicle? Advice appreciated.

As an afterthought, at what temperature range is it ok to run the car at (the outside air I mean) and is it better to run it with/out the body on? It's currently about a zillion degrees below absolute zero in KS and I want to try my car out in the snow >_>

 

[Cupooterluvr]

Come on guys this is a serious question! Why isn't anyone answering me?

 

[olds97_lss]

Do you have a temp gun? We can't really tell you how lean/rich the engine is by the run-times you get with it. We need to know the temps of the engine.

It sounds like you have it out of tune quite a bit. High idle, weird throttle response on the low end, not shifting... all add up to bad tune pretty much across the board.

I do know that the header/pipe combo that comes on that is pretty restrictive and it's robbing you of power. It's very similar to the HPI NMT.

The switching between high and low tone could be it shifting as well... it's a tough call. I watched the vid on that website and it's one of the worst I've seen. I never heard theirs shift either, but they were driving it in horrible locations for the vehicle.

 

[jetmechG550]

Proper temp should be 230-250 give or take a few depending on conditions. You can run a little hotter if your still leaving a good smoke trail. Running cold can have the same effect of as running hot in that it's not good for the motor. In your case since it's cold as you say, that could be you whole problem. If it's too cold and not running at a normal operating temp your probably not shifting and you'll be hard pressed to get it to do so. In extreme cold temps it's best to let it sit as you'll have to fight to get it to a decent temp. If it's not extremely cold you can wrap the head with foil or a sock or something similar to help keep a little heat in it. One thing to add, have a little patience, someone will answer. It's a saturday and there's lots of football on and people are out.

 

[Cupooterluvr]

Well, I basically asked for the most inexpensive one I could find, since they wouldn't pay too much. But I believe that the settings are as follows: about 2.5 turns in from flush with highendneedle, 3 turns in from flush with lowendneedle, and about a 1mm air space for idle. There's a nice thick stream of smoke coming from the exhaust at higher speeds, and it's not spitting fuel at idle.

Editing in response to prev. post: I was running it 2 days ago in about 50-60 f temps and it was running good (or it seemed so) but then it got cold.

Also, do these cars usually stay running unless you crash or leave them at idle for a while, or do they stall a couple times seemingly at random. Because if they are always supposed to run smooth, my car is so messed up that I'm probably screwed.

Wait I just thought of something: could it possibly be that the glow plug is not reacting fully to the fuel and not getting to max temp?

 

[olds97_lss]

Typically, it has more to do with the tune than the fuel or glow plug. Granted, the wrong plug with the way wrong fuel can cause issues.

3 turns in from flush sounds excessive for any engine on a LSN. You might want to back that out a turn or more.

Random stalling is typically a cause of wacked out tune. Too lean makes it run hot and the glow plug will fry or it will just flame out due to the fuel igniting way to early in the cycle. Running to rich will cause serious bog off the line and the inability to ever reach top RPM's and then it will flood and die if it idles for very long.

How long does it take to die (once you've gotten it running long enough to warm up) when you pinch the fuel line? This is how you can ballpark your LSN. If it dies in under 3 seconds, it's lean. If it dies over three seconds, it's rich.

 

[Cupooterluvr]

Well, I would try that method, but it's too cold outside to even start it. :\

But I will tune the LSN like you said. I think it's running rich at high ends because it doesn't ever reach 2nd gear. But it is better than too lean, that's a fact.

Nobody answered my question: which way do I turn the tranny screw to make it shift sooner? And is it better to run with the body on/off at what temperature range of the outside air?

 

[jetmechG550]

You'll probably turn it in, or tighten it to shift sooner, however, read my post again, your not dealing so much with a tranny issue as you are a temp issue. It's too cold as you said for the engine to get to operating temp, if it doesn't get to proper temp it won't shift because the rpm's on the engine are not getting high enough.

 

[olds97_lss]

Every trans I've dealt with you had to loosen the 2 speed adjustment screw(s) to make it shift sooner.

t-maxx, revo, savage, mammoth and LST all turn out (loosen) to make it shift lower in the RPM range.

 

[Cupooterluvr]

My engine has a logo on it that says "vx-18" and has a logo of a dot with three concentric quarter circles. My local hobby shop says that its unusual in that it has a four-screw-hole starter cord. Maybe it's a Vertex engine?

Ok here's an idea: go to this link http://www.exceedrc.com/sparepart51c06.html and save the picture of the car with the engine in the bottom left (the one you see when the page first loads) and open it in your picture veiwer, then zoom in until you can see the logo on the engine.

 

[EMPERORLAY]

When I went WOT with my jato it was hard to hear it shift. If you go part throttle on a long run you should hear it shift.

 

[Cupooterluvr]

What does WOT mean lol

 

[SkyMaxx]

What does WOT mean lol

WOT = Way open throttle. Means the thing is full throttle.

 

[Cupooterluvr]

K, Thanks. BTW which way do I turn which screws for richer/leaner mix? No, my manual DOES NOT say so.

Also, even with the idle air gap screw properly adjusted, whenever I hit the brakes at slow speeds, my engine stalls, how do I fix this? There's a 1-mm air gap when I fully apply the brakes so it doesn't need air gap tunage.

 

[Cupooterluvr]

Well, I basically asked for the most inexpensive one I could find, since they wouldn't pay too much. But I believe that the settings are as follows: about 2.5 turns in from flush with highendneedle, 3 turns in from flush with lowendneedle, and about a 1mm air space for idle. There's a nice thick stream of smoke coming from the exhaust at higher speeds, and it's not spitting fuel at idle.

Editing in response to prev. post: I was running it 2 days ago in about 50-60 f temps and it was running good (or it seemed so) but then it got cold.

Also, do these cars usually stay running unless you crash or leave them at idle for a while, or do they stall a couple times seemingly at random. Because if they are always supposed to run smooth, my car is so messed up that I'm probably screwed.

Wait I just thought of something: could it possibly be that the glow plug is not reacting fully to the fuel and not getting to max temp?

Um... Yeah. Anybody with know-how on nitro rc please email me so I can ask more about my car without annoying everyone with my multiposts.

P.S. BUMP!