LRP ZR30X won't start

[EF5]

I just purchased this engine and I'm trying to start the engine for the first time. The engine is set to 5 turns out high speed needle and 4.25 turns out low speed needle from factory for break in. The factory setting are 3 HSN and 2.25 LSN according to the manual. I can only get the engine to start at 2-2.5 on the high speed needle. I'm running 20% nitro 12% oil Byron's fuel with the glow plug that came with the engine. I've also tried a different fuel tank with new fuel line. I'm looking for any advice on what to do. I don't want to damage a brand new engine. Thanks for any help anyone can give. Thanks Ed.

 

[olds97_lss]

Personally, I set the needles to the base book settings. So, the book says:
• Mid range: 2.25 turns (low speed needle on the carb slide)
• Main: 3.00 turns

Set it to that, back the glowplug out 1/2 turn from tight to lessen compression a bit, heat the engine to 100F+ (closer to 200F is best) and give it a whirl. Once it's running, tighten the GP with your heater still on by turning the heater. Once it's running stable, keep blipping the throttle and take the heater off then tighten with a wrench.

I've broke in 4 LRP28S3's. Not one of them was easy the first few tanks and the tune was sketchy for the first 1/2 gallon. Easy starting with stable tune and solid power didn't really kick in until I got 3/4 to 1 full gallon through them. Every single one was VERY hard to start throughout the first 1/2 gallon without the engine temps being at 70F+.

Once you hit a gallon, it will be all smiles.

I also use the typical heat cycle method on all my engines. That said, I run at least 1 tank through it first without shutting down. I just blip the throttle and drive it around slowly on pavement the entire break-in. Then I only let them cool down to about 100F and fire them back up. From tanks 2-8, I'll lean them out a bit to get the temp up some. Sometimes they don't get to 200F until tank 3/4 due to being rich. Once I get 6-8 tanks through them and the engine is starting/running easier, I'll go 2 tanks before shut down/cool off period. After 10 tanks or so (depending on the sound of the engine and my gut feel for it), I don't shut down and I just gingerly run fuel through them by slowly accelerating up to WOT (3/4'ish throttle) and let off. One think I always do, during break-in and the entire life of the engine, I make sure to put the piston at bottom dead center (BDC) so that when the engine cools, it helps to retain the pinch in the sleeve.

Usually takes a couple hours to burn half a gallon or so. There's about 3800cc's in a gallon, half a gallon is around 12-13 150cc tanks. Usually by tank 15, the engines calm down and start easier, temps stablize around 220F. I usually try to tune to keep the temps between 210-240 for the first gallon, then I don't pay as close attention and just watch for smoke and listen to it. I check temps periodically while bashing and stay below 260F.

 

[EF5]

Thanks for the info. I'm just curious if you have ever pulled out your HSN. I did and the needle has a very steep taper at the end. I did heat the engine before starting and like I said the only range the engine will start is between 2-2.5 HSN. Is this because of the steep taper on the needle. That would make sense to me because a small turn would have much more of an effect. Most HSN I have seen have a much longer taper. My HSN has a very short like 2 mm taper. Thanks for the help. Ed.

 

[olds97_lss]

No, can't recall if I ever did.

I just took it out. Was at 3.75 turns from bottom.

I apparently need to dust a bit... This galaxy S5 takes pretty good photo's, these are shrunk/compressed... lol

I completely forgot to mention that my LRP's all like running on 25% byrons. They will run on 20%, but not nearly as well as they do on 25%. Makes a very big difference in overall performance/tuning/running temp. I use odonnel medium plugs as well as they seem to work the best for me.

I'm currently running a blend of 20%/30% (50/50) odonnel as my LHS didn't have anything else in the range I needed. Oddly, seems to run better. According to their site, it has less oil, but temps are very stable and I had to lean out the mix a bit. I run the same fuel in all my rigs to keep things easy. The TRX2.5 and 3.3 also like 25%. On rare occasion, my old LHS had byrons 25% in stock, but it was rare and I would always just by a gallon of 20 and 30, then mix it 50/50 in alternate jugs so I'd end up with 25%. Or close to it.

 

[ninnon]

Newer engines are harder to start- and olds97 has covered most of the great points to get you started- remember, once you do get it broken in, here's an excellent guide on tuning that will come in very handy:
https://www.rcnitrotalk.com/forum/threads/nitro-tuning-tips-and-tuning-flow-chart.60832/

No, can't recall if I ever did.

I just took it out. Was at 3.75 turns from bottom.

I apparently need to dust a bit... This galaxy S5 takes pretty good photo's, these are shrunk/compressed... lol

I completely forgot to mention that my LRP's all like running on 25% byrons. They will run on 20%, but not nearly as well as they do on 25%. Makes a very big difference in overall performance/tuning/running temp. I use odonnel medium plugs as well as they seem to work the best for me.

I'm currently running a blend of 20%/30% (50/50) odonnel as my LHS didn't have anything else in the range I needed. Oddly, seems to run better. According to their site, it has less oil, but temps are very stable and I had to lean out the mix a bit. I run the same fuel in all my rigs to keep things easy. The TRX2.5 and 3.3 also like 25%. On rare occasion, my old LHS had byrons 25% in stock, but it was rare and I would always just by a gallon of 20 and 30, then mix it 50/50 in alternate jugs so I'd end up with 25%. Or close to it.

Time to get out your pink fluffy duster, @Rolex should lend you his- or even wax it for you, if he's in a good mood.

 

[EF5]

Thanks for the replies. Yes, that is the same needle. My main concern is that the engine will only start at 2-2.5 turns on the HSN. I want to make sure it is running rich for break in. My local hobby shop only carries 20% so I will have to find some 30% and mix. When I get the other fuel I will try again and I'm hoping this will resolve my problem.

 

[ninnon]

Thanks for the replies. Yes, that is the same needle. My main concern is that the engine will only start at 2-2.5 turns on the HSN. I want to make sure it is running rich for break in. My local hobby shop only carries 20% so I will have to find some 30% and mix. When I get the other fuel I will try again and I'm hoping this will resolve my problem.

Sounds good- make sure you get some pics of it up and running in the media gallery

 

[EF5]

Thanks. I finally got some 25% fuel and the engine is now running. I didn't think 5% more nitro would make such a difference.

 

[olds97_lss]

I never broke one in on 20%. Read the manual before I bought it and picked up fuel before hand. I later ran some 20% (after it was well broken in) because I ran out of fuel while out bashing with my friends and all they had was 20%. Oddly enough... I went through 3/4 a gallon that day, I don't think the 3 of them burned 500cc's total! I tend to bash more than wrench when I'm out, I plan ahead for that too and get my rigs ready to go ahead of time to avoid down time.

Regardless, I was surprised how the engine responded to the 20%. Power dropped quite a bit and it ran hot, 20F+ more than normal. Don't know if that's typical or not, but I never ran 20% again in any of my rigs.

 

[ninnon]

Thanks. I finally got some 25% fuel and the engine is now running. I didn't think 5% more nitro would make such a difference.

it's quite a difference- especially in higher performance engines that will benefit more from the higher alcohol content.