Masterdave Posted April 22, 2023 Share Posted April 22, 2023 Brought my first new nitro buggy today, a hyper Vs .21. got it all together and took it out to the local industrial estate to run it in. It literally wouldn't start, checked and reset carb screws and no joy, couple of very brief ignitions but only for a split second. Ended up having to richen the LSN massively to get it to even run. The stock position is half a turn out from flush, this took a good couple of turns maybe more. Managed to get it through a couple of heat cycles, temp seemed fine. Going to bring it in tonight and reset positions back to stock again, am I missing something or do I need to be looking for a fault? Quote Link to comment Share on other sites More sharing options...
J.K Posted April 22, 2023 Share Posted April 22, 2023 It should start fine at the factory settings. Are you priming the engine before attempting a start? Also check the idle gap on your carb. It should be open about 1.5-2mm. Any less and it can have trouble maintaining an idle. Keep at it, the newer the engine the tighter everything is. It'll get easier! Quote Link to comment Share on other sites More sharing options...
Nitroholic Posted April 22, 2023 Share Posted April 22, 2023 Also.... check that the thing actually was at the base settings ..... I have had new engines set at all sorts of random settings, so while it ought to be set correctly for starting break in, there is no guarantee it actually was. Quote Link to comment Share on other sites More sharing options...
locky Posted April 22, 2023 Share Posted April 22, 2023 One way to quickly prime is to remove line from exhaust and blow down whilst watching fuel being pushed into carb. You can also increase the idle rpm by adjusting the throttle trim on the transmitter. as sometimes a more open carb helps starting. The HSN is the primary fuel flow needle so if this is too lean then the LSN will usually have to be too rich. There was recently someone else having starting issues using the Hyper 21 engine so not sure whether the needle settings are actually correct in the instructions. Try to keep engine temps around 200F for break in, preheating helps. Quote Link to comment Share on other sites More sharing options...
Masterdave Posted April 22, 2023 Author Share Posted April 22, 2023 Thanks for all the replies. I didn't touch the HSN during the day but checked it tonight and it as a half turn leaner than the run in specs. Measured out the idle gap to 1.3mm as a baseline, and reset the LSN to factory settings, fingers crossed tomorrow I'll be up and running. Keep any advice coming. I've played with nitro a bit before but only older stuff and a long time ago, so lots to learn. I'm definitely going to end up getting a brushless traxxas bandit for carpark antics when this isn't running haha Quote Link to comment Share on other sites More sharing options...
Masterdave Posted April 23, 2023 Author Share Posted April 23, 2023 Managed to get it running but won't hold any sort of idle, bog and than randomly runs away. If I drop the idle it just stalls. Anyone got any alternative baseline carb settings I can try? Im still suspecting lean Quote Link to comment Share on other sites More sharing options...
locky Posted April 23, 2023 Share Posted April 23, 2023 I'm assuming this is a new engine and car, so dont think there should be any air leaks. Tuning should be done when engine is up to temp. I use a typical paper clip to set idle gap which is about 0.8mm. Your idle gap maybe too high. Check the carb gap when all electrics are on. Leaning LSN should increase idle rpm. Adjust by 1/4 turns and adjust idle as necessary. Try testing with car off the ground. Quote Link to comment Share on other sites More sharing options...
Masterdave Posted April 24, 2023 Author Share Posted April 24, 2023 Managed to get it back to close to stock settings and running ok. Done a fair bit of idling and some low throttle driving on smooth ground. I've got my thermometer sorted now so I'll be able to measure running temps and tune accordingly. Also grabbed myself a hsp xstr brushed to tinker with when I get annoyed of the nitro tinkering and need a time out haha. Thanks for all the advice, been a massive help and I really appreciate it Quote Link to comment Share on other sites More sharing options...
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