can I just use [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXARR6&P=7]these[/link] instead of making one?

Thanks,

IBrakeForNobody

I brake, Yes you can.

k thanks!

It is also possible that the goo is oozing from the joint in the muffler itself. It can be fixed with hi-temp RTV (RED) silicone goop.

Yep, the tank is too high, center level it with the carb.... as far as the gunk on the engine, ( This is dangerous) in an old crock pot ( one you will NEVER use for food again) submerge the engine in anti-freeze and let cook for four hours... all plastic parts should be removed prior to cooking...... Allways remember, anti-freeze is a poison to you and dogs,cats ect..... Cool engine, rinse well with water, oil well, oil well, oil well...... Cptn Crash
PS we used to use sno saucers up north in the wintertime much like your air-truck....... they allso work on grass..........

Umm...well, I have 2 choices on fuel tank placement...1/2 in higher than the carb or a 1/2 inch lower than the carb. Its kinda frustrating.

Hmmmmm 1/2 lower with a pressure line from the muffler I think would be better.. seems like your picture showed the tank way too high. is it possible to just unhook the pressure line and try to adjust for gravity???? I like your truck concept but I bet it doesn't corner well??? Like I said in the previous post, up north we used those aluminum sno sledding disks. they worked really good on snow and marginal on grass, but they cornered well.......... Cptn Crash

The truck corners well, and it drifts too because theres no wheel power. Okay...so I'll set the fuel tank 1/2 an inch lower...

Fuel tank a half inch lower. My wrists hurt...changing the height involved unscrewing and rescrewing 12 screws...10 in which there was no way to get a screw gun to. [&o]

Hope it all works out for all the pain you went through........ good luck Cptn Crash

Okay....this thing has me like I wanna chuck it out the window (engine). It starts up, runs at idle, coughs a little, slows down, and quits. All in about a minute. But when I go to start it back up, it starts instantly. So, after going for about an hour repeating the process above about a million times, while messing with the low speed idle screw, I come here for help. The guy at the LHS said almost nothing useful...he said, "The wheel toe-in is off." [:@] That has like nothing to do with the engine. The idle screw is in about 2mm (covering about 1/3 of the air bleed hole). Please help! I'll take pics and give as much as I know what is going on if more info is needed.

Thanks a bunch for any and all help,
IBrake

Hmmmmm a few more questions......
1. Is your fuel fresh..... and what percent Nitro is it??
2. What type glow driver are you using??
A. And do you leave it on the plug while running it up to full rpm and then back to Idle??
a, This eats up any excess glow fuel in the crankcase and brings things to " normal"...
3. Are you sure you have NO air leaks at the carburator connection???
4. I see an add on carburator screen, is it perfectly clean??
5. Your opening in the throat of the carb, does it completely close at idle ?? Does it completely open at full rpm??
A. completely closed will obviously be a full choke situation, not good
6. Taking off the pressure line from the muffler ( clean it ) blow into it, Does it seem tight, or are you loosing pressure somewhere??
7. Do you ever see bubbles in the fuel lines???
8. have you removed the main needle and blown fuel through from the tank to wash it out??
9. Is your crancase backplate tight and not leaking pressure??
A. Holding thumb over venture opening and flipping prop over and removing thumb and flipping it over ( throttle wide open) Is there a big difference in the way the compression sounds, if not you have a backplate loose or leaking.....
10. Your 100% land/dirt craft is prone to take in a lot more dirt than an airplane, is your carb clean???
11. Your air screw ( for low idle) may be out too far try 2/3 at least closed, see #5 above....
12. try loosening the tank and raising it up while trying to run engine....
Remember a couple little things will mess up the whole scheme of things... I allways go for high throttle settings with the main needle and then go for the low settings, allways remember that time between settings and runnings changes as excess raw fuel is used up back to "normal" inside the crankcase....... I hope some of this helps........ let me know... Captn Crash...

1. Yes, 5%
2. Ni-Starter by Sonic Tronics
3. No
4. Yes
5. Yes, yes
6. tight
7. Yes, because of vibrations/shifting fuel
8. Yes
9. Yes
10. Yes, it has a air filter, I cleaned out the carb with fuel (took the carb off) and I don't drive in dirt/offroad
11. Okay, I'll try 2/3 closed
12. That doesn't help. I tried it before and it floods the engine.

Thanks for the reply!

Hmmmmm
1. you are using 5% nitro..... I use 15% nitro on my OS 40 LA
2. Your throttle opening should NOT completely close at low idle, try opening it up a ways and then start the process of tuning it down to an acceptable idle by gradually closing the throttle and adjusting the settings...... gradually aquiring a good idle....?
3. Bubbles in the lines arent just because of vibration, you could have a bad fitting somewhere in line, this would let air into your closed system, I think yoiu said you changed your tubing, if not, then by all means change it, inspect your fittings carefully for hairline cracks ect....
4. have you taken off the carb recently? you said you weren't sure if it was leaking air there, possibly a new o-ring or gasket of silicone or something would ensure that is not one of the many possibilitys which all add up to a problem................
I'm hoping all this info is more than just a jumble of confusion....... Cptn Crash...

IBrake,

You already know this but I will repeat it. There should be no air at all in the lines. Any bubbles can and will make adjusting the engine hard as it will be very inconsistent. Based on everything in the first post when an engine coughs then slows to a stop it's too rich. After it dies it fires right back up which pretty much confirms that. An engine that died from being lean will not always start right back up.

This is an air bleed carb so to lean it you turn the screw out (counterclockwise). I looked in the OS40LA manual on OS's web site and there are no factory settings listed so it will be tough. On the 46AX non air-bleed carb the factory settings are 1.5 turns on the idle screw and 2 turns on the high speed needle So this may be a fairly good starting point

Set the high speed needle 2 turns open, close the air bleed screw and open it 1.5 turns.

This setup will result in a sloppy rich engine when it starts

Now start it and leave the glow driver on and get it to full throttle. Now slowly lean the high speed needle 1/8 to get max rpm then back off 2 or 3 clicks. Now take the engine to high while still leaving the glow driver on.

Let it idle for 5 seconds then blip the throttle to no more than 1/2, 1/3 is better. If it hesitates, blubbers, spits fuel then return the engine to idle and turn the air bleed screw 1/8 turn counter clockwise. Keep doing this until the engine quits blubbering, spitting fuel.

Now go to full throttle and it should now transition fairly well. Leave it at full throttle for a few seconds then go back to idle and remove the glow driver. Now once again go to full idle all the while listening to the engine. It make go right to full throttle or it may spit, blubber. Now bring it to idle again and go to 1/3 and right back to idle, If the transition is nice and quick and smooth then you are OK. If it blubbers and stuff then turn the air bleed screw 1/16th turn counter clockwise. and retest to 1/3 throttle. Keep going at this until the transition to 1/3 throttle is nice and quick and smooth.

Once you have that then retest the transition from idle to full throttle. By now it should go smoothly and quickly to full.

You should be done.

Now let it idle and see if it just sits there and purrs. The occasional miss and spit can be expected if you are getting air on the lines.

I know it sounds like allot but it usually takes about 10 -15 minutes to do what I suggested but if all things are fine then you will be rewarded with a nicely tuned engine.

If you cannot get the transition to smooth out then it's possible that the air bleed screw or it's seat is damaged.

One other thing, what prop size/pitch are you using. To big a prop on that engine and you will never get it tuned or running right

Sorry if I am making recommendation that you may have already tried

Captain and bubbagates,

Thanks a many for the help! I'll try that process tomorrow morning. I don't think the air bleed screw seat is damaged because this is a new carb. I bought it about 3 weeks ago because the old carb's fuel inlet nipple broke off. I am running a 10x6 prop which is one of the recommended ones.

Thanks again!
IBrake

Okay...finally got some time to do the above procedure...results:

High speed needle: 3/4 turn out from all the way closed
low speed idle screw: 1.5 turns out (1/2 of the hole open)

Idles like before with glo plug ignitor on, coughs and dies w/o it. Starts right back up, though.

Its really getting frustrating [:@]

I think I figured it out...after 2 hours of frustration, I finally switched to the 10% I have for my .46 and it purrs like a kitten (I ran 5% before). That 10% solved all my problems...it transitions smoothly, and idles strong (H.S. needle 1 turn, 2 clicks out from closed; idle screw 1.8 turns out). Is the fuel my answer, or will using it be a Band-Aid over another problem that could occur in the future or a Band-Aid for a bigger problem?

Thanks,
IBrake

i think you worry too much mate,if its not broke dont fix it?.,its running ok now isnt it?ok so just leave it alone and enjoy.im no expert but maybe the fuel is the problem because the 5%fuel might be too lean if the engine is new!!.oh did you manage to get round to reading the instructions yet mate?

Sounds like that you have a solution there...... sometimes the most complex problems have the simplest fix............ enjoy ........... cptn crash

The engine has like 3-4 gallons of 5% through it...thats why I was wondering if it was safe to use 10%.

Thanks.

no worries......... just do not lean the engine ... like I said way before, I use 15% all the time just let her run a little rich and she like most females will be happy hahahahahahha later............ captain crash, ..........Old Wisdom,, its like golf I guess, if you do not make a divot every now and then, you are either too good or you aren't trying hard enough.............

k thanks. Probably the only time I'll lean the engine is in a drag race with another PPC (we are both using .40s but the guy I'm racing has a lighter car) and a 1/18 scale brushless RC truck. And I'll probably lean it to the MAX [>:] or right near it . Its running nice and rich right now, BTW.

Drag Racing..... Hmmmmmmmmmm OK now we are talking..... since you operate your perticular vehicle on a flat plane of use and not in the air, you should tweek your prop use.... the pitch in excess would affect an air craft, the diameter in excess would allso affect an aircraft, however your OS 40 LA will only reach a certain RPM, thus leaning it out to the max for a race is only gonna slightly increase the revolutions....and decrease the life expectancy of the engine slightly..... a higher pitch prop will pull it farther faster with the same revolutions............. Yet just 2 more of my cents worth...... now get out there and kick some butt.......... Captain Crash.... Happy Trails

What kind of prop? a 10x7? 10x8? I have a 10x6 on it right now...but a 10" or smaller prop is all I have room for. [:@]