RC trouble

[Ben]

Wondered if any of you could help. As you all know i have an HPI rush evo. Im having bother with it though. Since i fitted the new fuel tank. Basically, when i start it up - it wants to move! Like its revving too high. Ive read the manual to try and undertstand how to sort it out but just can get it sussed. Anyone have any ideas on how i can sort it?

 

[Ben]

just noticed too that it only seems to be when i turn the tranny on that it goes wild, it will cut out if i dont turn that tranny on though

 

[Grant]

what % of fuel you using?

 

[Ben]

20, same ive been using all along. I have had a bit of a fiddle with it and ive got it too the point where ive got the 1mm gap in the carb when breaking so thats ifne, ive sussed how to set neutral so it sits at normal revs when i start it up but im left with one problem! When i brake, it stops but when i take my finger off the brake it speeds up, its not returning to the neutral point after breaking grr!

 

[Grant]

cos at the moment i have the same problem i have just got a new engine for mine and i've got 16% but as soon as its starts its reving its nuts off, and if you move the throttle down its slow a little then cuts out, but when you give it more power its goes fater then cuts out, i am very comfused i have tryed playing about with the mixture and no joy at the moment, but the man i got it from reacons that i should be running it on 5% i didnt even no it went that low lol. have you got any sugestions?

 

[Ben]

not really since im looking for help lol

 

[Ben]

ok so after 4 hours or so, finally got mine up and running. Its just a question of percerverance more than anything. Basically took the air filter off and sat and played with the carb screws till i finally managed toget it sitting just right. The only tiny problem i have now is that when sitting in neutral, it has a tiny tendancy to wander off but not fast.

Just keep finger on the brake button will sort that out though. Im exstatic, might not sound much but tis been doing my head in. Thing is its on ebay at the moment as im a bit low on cash so wasnt willing to sell it when it wasnt working properly.

I really dont want to fiddle with it too much as ill end up having it not running again but if anyone knows an exact how to of how to stop it wandering off that wud b smashing.

 

[Ben]

thanks for all your help but i got it sussed, think i have learnt mroe about Rc control cars in the past 4 hours than some in a lifetime ha ha. Grant add me to msn mate and i will try and help you out a bit - [email protected]

 

[NeX]

sounds like you are getting too much air in... like the fuel is blocked and only air is going in to the cylinder. because they run on gas expantion rather than explotion they tend to over revv themselves when the fuel is reduced.

although you have fixed it, i'd check the fuel line, did you change the guage of tubing?

lots of fun those little things did you see in Redline (i think) they raced one down the M1!!! thats when you don't want it to cut out lol

 

[Ben]

haha nutters, no i never changed the fuel line as the replacement tank i got was exactly the same as the original one. Its all working beautifully now though. I was only so worried because i put it on ebay last night and then this morning it was giving me aggro and i wouldnt have let it go if it wasnt running properly.

Im deffo gonna get another one when i have a bit more of the queens english

 

[micraROB]

lol the joys of r/c i am always ####ing mine up and ahveing to mees with it lol just ruined yet another servo due to water but anywasy mate it could be that the new tank has a bigger out let if ya get me and lets slightyy more fule in at 1 time

 

[Fordy]

but the man i got it from reacons that i should be running it on 5% i didnt even no it went that low lol. have you got any sugestions?

use the recommended % by hpi which is 16%,

ben, ive found my brothers to be a bit tempermental at times i think its mainly due to the fact the engine is still new and every time you run it, it wears a little more therefore putting the needle settings off.

also if you tune a engine when its hot outside (if its ever sunny in the uk) you will have to tune it again if its colder the next day, temperature changes can effect the engine tune alot.

and these nitro engine dont like air leaks, if you have a air leak you will get high engines temperatures, high idle and tuning problems , the common places to leak are the base of the carb, and the back plate where either the rotostart or pull starter mounts, you can seal these up with normal high temp silicone sealer, engine sealer will work aswell

on the transmitter there is also 2 trimmers (knobs) for the servos if these get moved on the transmitter the servos will more aswell,

micraROB, there is a thing called plastic dip which alot of rc people use to seal up the servos so water doesnt get in them, ill see if a can find a video of the savage in a lake pretty cool to watch

edit: im uploading the video of the savage aka the duck, i will post up a link soon

 

[Fordy]

heres the video for everyone

http://homepage.ntlworld.com/richard.short40/water.wmv

ps this isnt my savage

 

[Ed]

sounds like you are getting too much air in... like the fuel is blocked and only air is going in to the cylinder. because they run on gas expantion rather than explotion they tend to over revv themselves when the fuel is reduced.

Thats not true.

They run in a similar way to a diesel. First of all you heat the glow plug, then the fuel they run on ignites when combined with the cylindar pressure and you remove the power to the glow plug but the cylindar pressure from the compression keeps the glow plug glowing which in turn keeps the fuel igniting. Its also why you get differnt heat range of glow plugs, for different fuels.

The reason why they rev up when there is less fuel as they run lean, and just like a car will overheat and can sieze.

 

[Ian]

you need to set your low needle which is on the side of the carb slightly more. Reduce the size the of the carb opening on idle by screwing it in a bit at a time. Do it until the car doesnt take off any more . Mines doing the same atm, need to set it up when the weather warms up

 

[Ed]

I sold a serpent impact Mk1 to a guy years ago, he couldnt get it to start so took it to a shop where a 'pro' said the engine was screwed. He phoned me a little irate, so I said no problem bring it back, he came back and 3 mins later with the car now properly set up it was running sweet as a nut. It amazes me how little good info comes with kits like this. If you dont have the feel or experience for these engiens they can appear to be totally troublesome.

 

[NeX]

Thats not true.

They run in a similar way to a diesel. First of all you heat the glow plug, then the fuel they run on ignites when combined with the cylindar pressure and you remove the power to the glow plug but the cylindar pressure from the compression keeps the glow plug glowing which in turn keeps the fuel igniting. Its also why you get differnt heat range of glow plugs, for different fuels.

The reason why they rev up when there is less fuel as they run lean, and just like a car will overheat and can sieze.

i thought the fuel didn't ignigte it just turned to a gas quickly... TBH i have no basis for this other than my own experiments. i took the exhaust off to see if i could see any explotions going on. all i found was nasty toxic gasses comming out.

i think i didn't explain myself proplerly, i thought big_ben's car was running lean which was why it was high revving and one if he'd just changed the fuel tank then a fuel block would make it run lean...

 

[micraROB]

imo that vid is calss

 

[Courior]

ive got a Silver Snake. had a .12GS engine in it. but now its got a .26 Hot Bodies engine in it. it is silly fast. anyone round south london wanna meet up? have a little RC fun? its v boring on yer own going round in circles.