HPI Trophy Truggy 4.6 V2 HSN issue

[antonio76m]

Hi all, hope as always in your precious support

I've got this new Truggy which looks and sounds amazing until.....

 

Day1. When received the Truggy, I did the standard procedure of breaking in the engine and just to be on the safe side, I doubled all the tanks, so basically more than 1 litre of 25% nitro for breaking in, all fine, amazing car, in a word  ... SMASHING!!

 

Day2. next day went to a car park to get it tuned, all worked fine, HSN done perfectly, LSN not much to adjust it wow great, acceleration etc good, idle perfect, smoke always visible, as I left a little tiny bit rich just for the first days , so day 2 perfect, proud of my car

 

Day3. and here the problems start, went to a park to do some speeding and some jumps, that what I thought, so filling te tank, connecting the glow plug igniter, pull the cord, nothing, pull again, nothing, again, it started, ok that could be normal .... after few rev to build a bit of heat removed the igniter, car stall, so again, start first pull, few more push to heat up, removed the igniter, engine stalls, so I remembered quite few guides and also HPI FAQ that if the car stalls after removing the igniter means you are running rich on HSN, so start turning 1/8 at the time as it was always stalling, finely got it working, but by the time it worked I did more than 3 full 360

[behappy2755]

Ok to me this smells like a bad GP. Replace it now.

If this doesn't work:

You're right that lean means better ignition. This is becuase the perfect air:nitro burn ratio is on the lean side. We go slightly more nitro to keep thing lubricated. This is normal.

It could also be that your fuel is too old to burn easily without high power ignition from your GPI. How old is your fuel/ when is the use by date on the bottle? Where have you been storing it??

Back to the glow plug. Ever wondered why the car keeps running after you take the GPI out?? Well I used to think it was the flywheel that generated an electic impulse... Bur it is actually that the GP keeps getting warmed up by the previous combustion, and ignites the next mixture, which warms it up again.... You're breaking it in, quite well in fact, but even though, GP's often get fouled at break in.

Hope this helps

[antonio76m]

Ok to me this smells like a bad GP. Replace it now.

If this doesn't work:

You're right that lean means better ignition. This is becuase the perfect air:nitro burn ratio is on the lean side. We go slightly more nitro to keep thing lubricated. This is normal.

It could also be that your fuel is too old to burn easily without high power ignition from your GPI. How old is your fuel/ when is the use by date on the bottle? Where have you been storing it??

Back to the glow plug. Ever wondered why the car keeps running after you take the GPI out?? Well I used to think it was the flywheel that generated an electic impulse... Bur it is actually that the GP keeps getting warmed up by the previous combustion, and ignites the next mixture, which warms it up again.... You're breaking it in, quite well in fact, but even though, GP's often get fouled at break in.

Hope this helps

 

I've checked the GP and it is glowing like new, the fuel has no expiring date and anyways is quite new and running good on my rally game car, no issue there,

 

The strange thing is that it worked fine first 2 days, day 3 on a park had the problem and tonight it was working quite fine, so there must be some sort of setting I'm missing or maybe I need a colder GP for hot day, does it make sense?

[behappy2755]

No, it's not the temp of the glowplugs that relates to the outside temp. The GP temp means how hot it burns, so cold is colder buring than hot. To ignite a high nitro fuel you don't need that much heat, because it is easy to ignite. For example, you might use a cold rated GP for 30% nitro, and a hot one for 18%.

Good point though, I see your thinking.

What nitro are you using, and what does it say on the side of the GP?? eg. "No.4"

[antonio76m]

No, it's not the temp of the glowplugs that relates to the outside temp. The GP temp means how hot it burns, so cold is colder buring than hot. To ignite a high nitro fuel you don't need that much heat, because it is easy to ignite. For example, you might use a cold rated GP for 30% nitro, and a hot one for 18%.

Good point though, I see your thinking.

What nitro are you using, and what does it say on the side of the GP?? eg. "No.4"

 

nitro fuel is SPM ATOMIC Gold 25% and the GP is a stock HPI R5 which in HPI web site is stated as cold

[behappy2755]

Ooo, this is a tricky one. There isnt much logical adjusting, just guessing. How about trying a med hot?? Or rebuilding engine, it always helps even though it's so time consuming. There has been soo many people blaming their tuning, when their engine isnt sealed...

[antonio76m]

Guys, RC world is really a big mister yet to be discovered for me, went out today with my truggy, bought a starter box as my hands can't take any more of this pull start, anyways, without touching any needle, start the car with the box, started like a charm, even after removing the glow plug car was fine, temperature are fine ... but ... there is always a ******g but, well problem is now that the wheels are keep spinning, following the break in diagram in the forum, I set all the needles as standard factory, first set the HPS ... ok, then tried to adjust the idle, kind of was ok, when break applied engine did not shut off, but wheel still spinning, so the diagram says that if the wheel are still spinning I should richen the LSN, did that, 1/8 at the time, eventually the engine would bog when accelerate, but wheels still spinning, no way of stopping them, while driving the car move on its own even if I turn the TH switch on the remote all the way to the breaks, it stops only if I pull the brake from the remote.

so anyone can advice?

thanks

 

 

Edit: I've been reading around, could it be that the clutch is broken? the car has just 2 liters of fuel and is like brand new

Edited April 13, 2014 by antonio76m

[AdrianM]

I'm having the same problem with spinning wheels. Reducing the throttle or turning the LH button just causes it to stall.

Phoned HPI who who really helpful and suggested it's the throttle servo. I honestly can't see how it could be as the throttle is fully "off" and a servo couldn't push it any further in at all.

I'm going to run a few more tanks and hope it loosens up so it will handle a lower idle speed I think. Anything seems worth a go!

Happy to try any other suggestions of course.

Adrian

[antonio76m]

I'm having the same problem with spinning wheels. Reducing the throttle or turning the LH button just causes it to stall.

Phoned HPI who who really helpful and suggested it's the throttle servo. I honestly can't see how it could be as the throttle is fully "off" and a servo couldn't push it any further in at all.

I'm going to run a few more tanks and hope it loosens up so it will handle a lower idle speed I think. Anything seems worth a go!

Happy to try any other suggestions of course.

Adrian

 

Hi Adrian,

I'v open it up to check the clutch spring/shoe, and the clutch spring was broken so the clutch shoes were always engaging the clutch bell

 

I took a used spring from the Bullet engine as the engine need to be replaced, while ordered a brand new one, after changing the spring the issue disappear, anyways, to be on the safe side I've ordered a professional complete clutch with 5 shoes specific for truggy/buggy as I don't trust anymore this kind of clutch springs

 

so I'd suggest you check out your clutch spring as well

 

cheers

[AdrianM]

Ah I see. I hope it's not that as it's brand new and only done about 2.5 tanks.

Weirdly though, for a brief 3 or 4 secs the wheels stopped while turning back the handset TH switch, then it stalled. Surely that wouldn't point to a clutch problem?

I'll have a look tonight though I think. Many thanks for the reply.

Adrian

[Joeloliver]

Hi all, hope as always in your precious support

I've got this new Truggy which looks and sounds amazing until.....

 

Day1. When received the Truggy, I did the standard procedure of breaking in the engine and just to be on the safe side, I doubled all the tanks, so basically more than 1 litre of 25% nitro for breaking in, all fine, amazing car, in a word  ... SMASHING!!

 

Day2. next day went to a car park to get it tuned, all worked fine, HSN done perfectly, LSN not much to adjust it wow great, acceleration etc good, idle perfect, smoke always visible, as I left a little tiny bit rich just for the first days , so day 2 perfect, proud of my car

 

Day3. and here the problems start, went to a park to do some speeding and some jumps, that what I thought, so filling te tank, connecting the glow plug igniter, pull the cord, nothing, pull again, nothing, again, it started, ok that could be normal .... after few rev to build a bit of heat removed the igniter, car stall, so again, start first pull, few more push to heat up, removed the igniter, engine stalls, so I remembered quite few guides and also HPI FAQ that if the car stalls after removing the igniter means you are running rich on HSN, so start turning 1/8 at the time as it was always stalling, finely got it working, but by the time it worked I did more than 3 full 360

[antonio76m]

 I am looking at getting one of these HPI Trophy 4.6v2 Truggy RTR. I am interested to know if it's been ok for you and has it been durable.

 

Thanks

 

Hi, ok so far, its quite funny and tough, few problems at the beginning mostly for lack of experience

anyways, if you decide to buy it, i'd suggest you change the whole clutch with a better 3 shoes one, change the air filter with a non waterproof as my was getting full of sand and dirt and to help not having trouble with starting it, as I got, i'd suggest a starter box, so no need to remove the pull cord to replace with a rotostart but its also an alternative, 

cheers

[Ben Willis]

The wheels spinning all the time could simply be that the idle screw is too far in and holding the throttle open try backing it out slowly with the engine running and idling

Sent from my iPhone using Tapatalk

[almighty15]

Hey dude!

 

You have the same engine as my Savage does so this will be quite an easy one.

 

1. Change the plug to a medium, the stock plug is to cold for the current temperatures we're getting and will cause temps to be all over the place.

2. Have you set you idle? After break in you should always re-tune your idle as the amount of fuel entering the engine after break in is completely different then it was at factory settings

3. Do the revs die down just before it stalls? If they do then then the plug isn't hot enough so change to a hotter plug ( See point number 1 ), if they don't slow down and engine just stalls then the low speed needle is too rich.

4. Adjusting the high speed needle to get the car to idle won't do jack, you know why? Because it's a high speed needle, not an idle needle, or a low speed needle.

5. Instead of adjusting the needles 1/8th turn the like manual says use 1/12th turn instead.

6. A rough and dirty way to check your low speed needle is to pinch the fuel line, if the engine cuts out pretty much instantly then it's too lean, if the engine ticks over for longer then 5-6 seconds it's too rich.

 

Best thing you can do now is revert back to stock settings and start leaning out again, adjusting the idle speed as you go to suit the new settings.