Engine stalls when jumping

[Dandare]

One particular jump on our local club track last night resulted in repetitive stalling, not too sure if it stalls mid air or on the landing.

I've had suggested that something may have stopped the flywheel upon landing but i currently have the hole taped up due to using a pullstart & the track being very dusty etc & the tape is still intact. I guess it must be something to do with the landing rather than mid air but it's a mystery as to why ?

I replaced the clutch shoes/springs between the 1st & 2nd round but it still kept stalling, could it be a tuning/lsn setting issue ? I've made sure the idle is set so when braking the revs don't drop etc etc, i'm at a bit of a loss...

Car is a TT EB4-s2 1:8 buggy, standard .21 engine etc.

[reg]

Hi,first off change ya glow plug,if it doesnt do the trick it sounds like it might be the clutch or engine bearings,when you say you have taped the hole up,do you mean the one the fly wheel shows through the chassis,if so take it off,covering it will stop any little stones falling out as they will get stuck in there,you shouldnt cover it up,they are ok running in dust and dirt,make sure there isnt a little stone stuck between the fly wheel and the engine case,
there is a few things to try

[Dandare]

hi, i did replace the glow plug to no effect. I take your point regarding small stones, i just figured covering it up would more likely stop them getting in in the first place more so than stopping them escaping.

Would there be a way to check engine bearing problems ? I must have run approx 70+ tanks through it by now...

[reg]

Originally Posted by Dandare

hi, i did replace the glow plug to no effect. I take your point regarding small stones, i just figured covering it up would more likely stop them getting in in the first place more so than stopping them escaping.

Would there be a way to check engine bearing problems ? I must have run approx 70+ tanks through it by now...

The stones will get in places you cant cover up,70 tanks isnt realy alot but they dont last for ever,plus you say you are running a pull start,that will let dust into the rear bearing,you could try taking the pull start off and borrowing a starterbox,sometimes the one way in that locks up if its dry,i cant help with how to test apart from look for play in the crank shaft,

[reg]

also try doing a few laps to get the engine up to temp,then bring it back to the start,let it idle for 10 seconds then floor it,see if it stops or pulls off,

[Dandare]

Ok, thanks for your help.

Regards to the pullstart, i keep thinking of changing to a box but i've never had any trouble using the pull so i've kinda stuck with it. I see others at the club sometimes having trouble starting even with a box, lol. Maybe i'll change for economics (i am on my 3rd pullstart) reducing load on the engine & what you've said regarding the bearings/one way bearing.

[lewis666]

hi dan,

it is lewis cocksedge here i dont know if u know me but i was running last night as well using the white durango? i work out of the green van? anyway what is your airfilter like? i found that because of the dust airfilters where getting so clogged up they would start cutting because the engines could not breath.

another solution is did the car cut when u give the car throttle after the jump? if it was then the car could have been wheel spinning alot causing the engine to overheat and cut. my car usually does about 10 minutes or so on one tank but i only had about 7 minutes last night because of so much wheel spin.

i would not look at the car for the cause i would look at the track. it was stupidly dusty i didn't run the final because it will ruin the car. i heard someone say oh the tires will last longer. well i dont care how long the tires last but i do care how long my engine and car last because they cost a hell of alot more. i think since the change it is a poor track.

hope this helps

lewis

[Dandare]

Hi lewis, not sure if we've spoken or not though i do recognise your car every time it goes past me
I took 2 clean filters with me (2xinner & 2xouter), couldn't believe how filthy it was after only the 1st heat, so cleaned it & then replaced it entirely for the final. The stalling does seem a bit random though ie, clean or dirty filter, hot or cold engine etc etc. I'm hoping i may have just got unlucky & that it may have just been a small stone caught up in the flywheel upon landing

As regards to the track, i like it slippy as i find it suits my driving but last night was something else, any dustier & we'll need foglights

Maybe each of us should bring a broom next week & turn up an hour early, lol.

Dan.

[racingdwarf]

Hi dan

check you engine idle is not set to low, if you get random cuts this can be the cause as if idle is to low engine can cut on landing etc, this can also cause cuts when upside down or in a hard crash.

Take care tho as if you are running in very low grip conditions and have the idle set to high it can give you the fealing the car is running away with you.

your idle shouldn't realy change under breaking in race conditions, idle will normaly drop down after the car is just sitting for 10+seconds

Also check your engines compression when hot, as random cuts and having to turn the idle up can be a sign of a worn piston and liner

Dave

[lewis666]

Originally Posted by Dandare

Hi lewis, not sure if we've spoken or not though i do recognise your car every time it goes past me
I took 2 clean filters with me (2xinner & 2xouter), couldn't believe how filthy it was after only the 1st heat, so cleaned it & then replaced it entirely for the final. The stalling does seem a bit random though ie, clean or dirty filter, hot or cold engine etc etc. I'm hoping i may have just got unlucky & that it may have just been a small stone caught up in the flywheel upon landing

As regards to the track, i like it slippy as i find it suits my driving but last night was something else, any dustier & we'll need foglights

Maybe each of us should bring a broom next week & turn up an hour early, lol.

Dan.

hi dan,

ok so it is not your airfilter. i take it wasn't cutting like this since the change of track layout?
i think it is down to the VERY loose dirt on top causing u to wheel spin and overheating engines. if u are still having trouble i can watch your car at the certain jump and try to find the cause.

many thanks

lewis

[mark christopher]

are you using the brakes in mid air? if its ticking over and you hold the brakes on does it cut?, somtimes the linkage can hold the throttle on and when you brake it drops to the idle screw

[Dandare]

I had it cutting out on me last week before the new layout, i'd finish each heat fine but then upon driving it off the circuit it cut out, then i'd find it more difficult to start again. It done this on both heats, then during the 10min final it cut out whilst being re-fuelled. This week with the new layout it cut out every time i took the jump positioned just before the final bend, before the main straight, weird

Dave, me & Rob decided to up the idle a little after replacing the clutch after the heat & in the final & cut out once, on the same jump, lol. Idle is now set a little higher than it used to be & i've made sure it doesn't dip at all under braking. regarding compression, may be something to check if this persists, cheers.

Mark, i was blipping the throttle mid air on that particular jump to help keep the nose up a little.

Thanks for the suggestions guys, Lewis, i'll see what happens next week & go from there, cheers.

[mark christopher]

low compression can also cause cutting out, though you normally there a pain to keep set up too.

its hard to know without seeing it, but hopefully somone has thrown a sugestion to help your way

[dave g]

if theres play on the conrod or engine bearings then an engine can cut after a harsh landing also.

[Dandare]

Ok, seems like there is a compression issue. Flywheel can easily be rotated through the hole with one finger only... bugger.

Tried racing at Norwich today but although it started/ran ok initially, during running when up to temp it kept cutting more so when off the throttle, idling & if it went over then wouldn't start very easily.

New engine time !

[MALLET]

Originally Posted by Dandare

New engine time !

Not necessarily, You can send your engine away to either myself or Dave g, and we will rebuild your engine back to good health. Saving you a lot of money

[Dandare]

Originally Posted by MALLET

Not necessarily, You can send your engine away to either myself or Dave g, and we will rebuild your engine back to good health. Saving you a lot of money

My engine is a run of the mill Thunder Tiger pro 21 BX-R ie, not hugely expensive to buy new. I looked at the cost of a new piston & liner alone at £53 without replacing bearings etc. I can get hold of a brand new engine for £70-80.

Please let me know how much to rebuild as it's always good to have a spare