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 Rank: Semi-Pro Level 1  Groups: Registered
Joined: 16/06/2014 Posts: 65 Points: 188 Location: Austin, USA
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I know I am not the only one that has started the car up and run it, but I don't hear many of you talking about it and comparing notes.
I broke mine in and tuned it (mostly) over the last couple of weeks when I had a chance. I am using 20% nitro and started it with the factory settings. Very Rich!! It took a while to get the High Speed needle tuned so I was getting good speed but now the damn car is too fast to drive on my street in front of my house so I need to move to a more open area.
How did you guys find the tuning process? Have you run it much? I have put almost a quart through it and it is running fine, albeit still a bit rich (on purpose, I am not racing it)
Any thoughts?
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 Rank: Amateur Level 1 Groups: Registered
Joined: 03/12/2013 Posts: 39 Points: 103 Location: uk
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Hi, I have put two tanks of 20% through with the car on a stand. I was quite surprised how easy it started with the factory settings although the pull start was stiff even when the engine was not flooded. once started and settled down I screwed out the idle needle to stop the wheels spinning this needs to be done gradually and in small increments as it takes a few seconds for the adjustments to take effect. I also reverted back to the original smaller pull start handle as the larger one kept falling apart. I have just today (a month later)the weather here in the UK has been pants! run a third tank of 20% through with the RB7 on the ground at a very low speed with a couple of blips . This time I found the car more difficult to start and wondered if it was residual fuel from the previous session a month ago. I found I had to screw the idle screw back in to keep the RB7 running and once started and warmed up was able to screw it back out again.I assume this is all to do with the running in process. This time I ran the tank dry so as not to leave any residual fuel in the tank so hopefully next time it should start easier. I have now received pack 25 parts 97-100 so i am in the middle of spraying the display body and finishing off the racing body.I don't think I will ever use the display body though as I don't like the idea of keep having to take the cylinder head off to fit it. I don't think it would be long before the screws would strip. I have also ordered the extension series as well now it is available looking forward to the two speed gearbox. 
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Rank: Semi-Pro Level 1 Groups: Registered
Joined: 16/06/2014 Posts: 65 Points: 188 Location: Austin, USA
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Idle can be finicky when the engine is being broken in. Just make sure to set the idle screw so when you accelerate and then fully brake the engine doesn't die. If you are having problems getting it to start when breaking in, instead of adjusting the idle screw to let more air in, turn the throttle trim on the controller to open the idle gap temporarily, then you can turn it down once it settles. You either had too much fuel in the engine (hard to pull the starter cord and won't start) or too little air getting in (won't start).
BTW, I do agree about the 'upgraded' starter handle. It comes apart all the time. I think I will switch back to the old one as well.
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Rank: Amateur level 2 Groups: Registered
Joined: 17/05/2014 Posts: 45 Points: 141
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Hi, I have just received pack 23 and am about to start my car for the first time. On reading page 469 of pack 23 instructions re carburretor set up it says "screw main needle valve all the way in clockwise and then unscrew 4 turns" Could anyone advise whether this is 4x180% turns or 4x360% turns? Also re previous comments re new pull cord handle. I think you may need to insert rod into the ring from the other way round as rod then "locks", in place . Mine is very firm and centered in the ring. (the wrong way round rod is slightly off centre and will fall out.
regards Phil
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Rank: Semi-Pro Level 1   Groups: Registered
Joined: 30/11/2015 Posts: 57 Points: 180 Location: Beds
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Hi 4 x 360 they mean, Have fun & remember to keep all 4 wheels off the ground while running in 
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Rank: Amateur level 2 Groups: Registered
Joined: 17/05/2014 Posts: 45 Points: 141
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Hi, thanks for info. I had thought that but wanted to check. I,ve made a block to put car on so will be starting it up soon.
Phil
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Rank: Amateur level 2 Groups: Registered
Joined: 17/05/2014 Posts: 45 Points: 141
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Hi, Just some feed back. I have now started up engine and run first full tank of fuel through. As I think others found, it was slightly more difficult to start than I expected but instructions good re effect of too much fuel in cylinder making pull cord hard (I therefore didn,t force cord but took plug out and replaced) without plug in, pull cord fine, so I knew no build problem. Engine ran quite sweetly, clutch / rear wheels responding as expected with increased speed. Wheels not turning when idling. I would still appreciate others input re carb settings ie. effect of main needle valve and idle mixture screws. I'm thinking the more these are screwed in the leaner the mixture? At intial stage of starting I did have quite a bit of moisture/?un-burnt fuel coming from exhaust pipe but with adjustment this stopped to just a minute amount, which I would expect. (It was also quite a cold morning.) Lastly fuel I am using for running in is Quikfire 10, recommended from my local model shop. This is 10% NM, 18% lubricant, & 72% Methanol.
I will also be using this mixture for a little while as only comes in half gallon container!!
What mixture would others recommend when this finished as they do apparently have a Quickfire 16, which is 16% NM, 18% Lub. 66% M.
Phil
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Rank: Amateur level 2 Groups: Registered
Joined: 17/05/2014 Posts: 45 Points: 141
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Hi again, one further thing. Although I posted a few days ago that I thought the new pull cord handle was OK, I now agree with others that certainly in this initial stage of trying to start engine, mine also fell apart several times (always at the wrong moment!) For now I have applied a small amount of super glue to rod/ring and will see if this holds when I next run engine. If not then I will also probably go back to the original handle.
Phil
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Rank: Amateur Level 1 Groups: Registered
Joined: 03/12/2013 Posts: 39 Points: 103 Location: uk
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Don't lean your engine off too soon!! or you could fry your engine. It is good to have unburnt fuel coming out of the exhaust during the early stages.leave your high speed needle 3.5 - 4 turns out during the first couple of tanks of fuel.Once you start running the RB7 on the ground at low throttle, if the RB7 starts to bog down then lean it out a bit more in 1/8th increments by turning the screw in.Once your engine is run in make sure there is still a blue smoke trail coming out of the exhaust.If not then it is too lean and you need to screw out the needle in 1/8th turns until you can see smoke is evident again.
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 Rank: Pro Groups: Joined: 24/08/2009 Posts: 48,827 Points: -13,348
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Nitro fuel is mixed with a lubricant, there will always be lubricant expelled as its a simple two-stroke engine without any other means of lubrication and the unburnt lubricant has to exit somewhere. If you lean out the engine too much to the point of it having minimal lubrication, it will either cease or wear out extremely quickly.
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Rank: Amateur level 2 Groups: Registered
Joined: 17/05/2014 Posts: 45 Points: 141
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Hi, thanks for replies. MrT, perhaps there could be something added to the start up instructions as to what t expect re lubricant coming from exhaust during running in with richer fuel. As completely new to this, it's something that did not register with me and may be others. As with lots of jobs the more info initially the better otherwise we learn by mistakes, which is not the best way. I will certainly run mixture richer for remaining tankfulls during running in process.
Thanks phil.
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Rank: Semi-Pro Level 1 Groups: Registered
Joined: 16/06/2014 Posts: 65 Points: 188 Location: Austin, USA
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Rank: Amateur level 2 Groups: Registered
Joined: 17/05/2014 Posts: 45 Points: 141
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Well I didn't think I would be posting a note so soon but now the pull cord has broken or just come off the reel, can't tell until I dismantle.(the length of cord which came out is 52cm long so I cannot believe it broke.) Again engine very hard to start with 2nd tankfull. It did run for about a third of a tank but on trying to re-start cord came out/broke. Looks like I'll be busy for a while!
Phil
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Rank: Pro Groups: Joined: 24/08/2009 Posts: 48,827 Points: -13,348
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Try not to over-pull the starter cord.
often a nitro car user think its like starting a petrol lawnmower or strimmer., the method is similar but just don't pull anything like as hard or to its full extent, as it will indeed strip the cord from the starter mechanism. Its more of being quick short tugs.
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Rank: Semi-Pro Level 1 Groups: Registered
Joined: 16/06/2014 Posts: 65 Points: 188 Location: Austin, USA
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Are you making sure the piston is at the bottom when you finish running the car?
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Rank: Amateur level 2 Groups: Registered
Joined: 17/05/2014 Posts: 45 Points: 141
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Hi I will check when I have replaced the cord whether piston at the bottom. Re MrT's reply, the engine will not let me do short small tugs. It is much too hard. I repeatedly have to take plug out to get cord to pull at all. I can hardly hold the car still from lifting in the air when I try to pull the cord. Without the plug in it is absolutely no problem and piston moves easily. There are just a few occasions when the pull start does work freely and then this catches you by surprise and thats when the cord came out. I would appreciate your views / advice. I am hoping that when run in this will improve. I did expect I would be able to pull the cord in short tugs reasonably easily (as I have seen others do with nitro cars) but this is not happening. If I had bought a ready assembled new car I would be taking it back as I cannot believe it should be this difficult. I have broken the skin on my fingers trying to start the car. Phil ps The super glue on the new pull cord handle works a treat and handle not now coming apart.
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Rank: Pro Groups: Joined: 24/08/2009 Posts: 48,827 Points: -13,348
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It sounds like you could be flooding the engine with fuel which would cause the piston to lock
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 Rank: Vice-Master  Groups: Registered
Joined: 05/04/2013 Posts: 540 Points: 1,630 Location: England
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pwormald wrote:If I had bought a ready assembled new car I would be taking it back as I cannot believe it should be this difficult. You would get the same issue with any shop brought nitro car. If it's cold you could try warming the engine with a hair dryer, that will loosen it and make it easier to start. I always end up doing this with new engines, especially smaller ones. P.S. I recommend using something like gardening gloves with the pull starter, it saves your hands. Finished 3D Printer, RB7, Hummer, Skyrider drone & Combat tank collection http://www.model-space.com/gb/
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Rank: Amateur level 2 Groups: Registered
Joined: 17/05/2014 Posts: 45 Points: 141
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Thanks again for replies which I do appreciate. Is it likely starting will become easier when engine fully run in? If not at least I know now and have a couple of tips to help. MrT could you please advise a few more tips on how to prevent engine flooding. I am currently following start up guide lines of filling tank and putting 2/3 drops of fuel directly in carb. When I've repaired starter, should I try without putting any fuel directly in carb. or doe it need this to start? Any more advice on how to prevent build up of fuel in cylinder would be really helpful and appreciated.
Regards Phil
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Rank: Pro Groups: Joined: 24/08/2009 Posts: 48,827 Points: -13,348
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Reduce the amount of fuel you are putting into the engine and ensure that the needle setting is not set too rich. Also ensure that your glow start is fully charged.
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