yekots

My Feedback: (1)

So I have a ST 90 that I have on my Goldberg Ultimate. I want it to look more scale so I am going to put a Graupner 3 blade prop on it. Any recomendations on which size to go with? I know 2 blade will give the best performance but with all the different sizes out there now in 3 blade I should be able to get close to the same performance right? Has anybody tried 3 bladers on a ST 90?

Thanks.

Bax

My Feedback: (11)

If the propeller will allow the engine to turn 11,000-12,000 RPM when leaned to just rich of peak RPM, AND fly your model as desired, then you have the "correct" propeller size. A "rule of thumb" for selecting a 3-blade propeller is to keep pitch the same and go to a 1-inch smaller diameter, so if a 12 x 8 two-blade propeller works correctly, then try an 11 x 8 three-blader...or whatever is closest. If you cannot find a three-blade prop that's close, then just go with the two-blade and get the good flight performance.

voodoodb

My Feedback: (98)

Fujiman, would you or anyone else happen to know what the needle settings are for the WT499 on a ST2300? I got my low end adjusted for a good idle, but the top end just seems like I can't get it richened up enough.

D

fujiman

My Feedback: (133)

voodoob, if you can't get hi needle to richen up, you may have to adjust diaphram needle lever height a tad so that the diaphram opens or pulls the needle farther off it's seat. give it a try. just don't over do it or you won't be able to control hi needle adjustment. also walbro has a needle control asortment kit to change spring strength to help lighten or increase tension resisting movement of diaphram. i don't remember the kit number, you'll have to check web at some kart racing carb. sites to find number of kit. might also want to buy 0r down load walbro carb. manual it can teach you a lot about how it setup carbs.

voodoodb

My Feedback: (98)

Thanks, I've been trying for 2 days now to get it to run. Seems to load up on low end, then If I make just the slightest movement towards leaning it on the low end, it dies, and won't restart. SO I have to richen the low again and go through the same process. With the low set where it will idle for a little,(still wants to load up) and move the stick to full throttle, right around mid throttle it will hesitate badly with lots of smoke, and you have to eithert go back to idle or jockey the throttle stick and finally it will go to full RPM. But again, if you lean the low end the most minute amount, it dies and won't restart until you richen it up. I don't know, I'm at the end of my wits with this Supertiger. For what I have in it trying to get it to run good, I could have bought a nice gasser of same or bigger size.

D

rc34074

My Feedback: (5)

voodoodb - I had no problems like you describe with wt499 carb on my 2300. It tuned right in at both high and low end. How long has your 2300 been run? Is your 2300 upright or inverted? Did you set both the low end and high end needle settings? The high end needle on my wt499 is set at 1 and 5/8 turns open.

By the way, what fuel are you using? I am using 10% Omega fuel in mine- always have used this fuel and it runs great in my G90s and 2300s.

Ed

fujiman

My Feedback: (133)

have you tried to leave the glow driver hooked up while doing your checks. could be a bad or improper glow plug. if your using an os "f" plug try one and see. your problem might not be the carb. have you tried a fresh batch of fuel, if your fuel is old or has been left opened for any time at all especially in winter it will soak up water. only takes a small amount to foul the fuel and give you fets. what % of nitro are you using. does your engine run ok at full throttle? are you trying to adjust the low needle at a too hi of idle "speed". also check and make sure you are filtering your fuel from can and tank to carb. check that there is NO debree under metering needle you'll have to take off pump led and diaphram and lever to take needle out to clean. don't give up if push comes to shove try a different carb and that would be my last thing to do. make one check or change at a time so you are sure of your results. go from the easiest to the hardest. some times if not always it turns out to be a very easy fix that we over look. we seem to go to the most difficult and we wind up over looking the simple things and we get frustrated. establish a chain in your diag. 1 glow plug driver left hooked up 2 glow plug bad or go to os f plug 3 fuel and nitro % 4 is fuel being filtered is it old fuel what brand? 5 internal carb problem???? junk under metering needle??? is the vent in flapper led being effected by cowl air pressure may need to solder a line in led and run vent line into interier of plane to equalize press in flapper chamber. 6 try another carb may be defective but i dought it but don't over look it. let us know what the results are could help the rest of us.

fujiman

My Feedback: (133)

real good advice

voodoodb

My Feedback: (98)

Fuji I noticed earlier in this discussion you said to tap the engine on the motor mount but not on the exhaust side. I tapped mine on the exhaust side. Why do you say not to?

D

fujiman

My Feedback: (133)

just to keep the pulse hose alway from the hot manifold/muffler and possibly getting burnt thru. other than that there is no reason, case pulse pressure is all the same no matter where you put the tap at, back plate, off the mounting lugs, etc.

NM2K

My Feedback: (14)

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fujiman

My Feedback: (133)

not sure what you meant "not under the carb" i run the pulse line from crank outlet case pressure nipple to the evo 26/35 adapter inlet nipple. the wt-499 has a hole or port in the base of the carb. some walbros of course or at least some applications don't use this type of set up. like the fuji 50/64 they use the pressure off the crank case to the carb. "lid" it's self via an external hose. in this case the port under the base of carb is not used. don't know if this is what you meant??????

fabmaster911

Why don't you guys just put an ignition on your engine and run gasoline at 15 or 20:1. You already have the carb in place, why mess with expensive glow fuel? Just curious.

fujiman

My Feedback: (133)

Gotta modify rod to be safe enough running gas in a glow engine the rod has to be fitted with roller brgs. or the rod has a good chance of seizing on crank pin. Someone here in rcu is fitting brg assemblies in S.T. engs. like the .90's and up. There is another thread here in rcu dealing with running gas/glow fuel mix and adding some oil to the mix to protect the roller brgs, pitons and liners in the gassers. what we have been talking about here in the S.Tig. thread is using the walbro wt-499 alky carb. on the tigres 2300 and up. there by over coming some of the tigres carb fuel draw woo's and allowing the fuel tank to be placed further back in fuse. to nuetralize c/g concerns. Eis ign. system could also be incorperated into this and give a reliable ign. With alky set up an on board glow system could also be installed, aiding reliability. If you go to using spark ign. a 1/4" plug will have to be used or you will have to modify head to accept a 10mm cm-6 spark plug. of course the use of a glow plug and onboard glow igniter simplifies things.

voodoodb

My Feedback: (98)

I don't do it for the added upfront expense of around $150 for ignition, plug, and bearings. I have anough in this engine as is, and have other gas engines if I can't get this one running.

Fuji, finally got it running. Used a new OS #8 plug and 20% Heli fuel I had. Didn't have any new airplane fuel on hand. Also I went in to the diaghram and bent the lever on the needle arm as you suggested. Alos I used the same fuel I have tried before, and it also runs now. So It's running, and at least I can try to fly the plane now.

I am having 2 things happen now however that I can't quite figure out.
1. When I go to full throttle from idle it revs up really high for a about 5 seconds, then backs off a few hundred RPM. I thought it might be lean, but I can open the needle and there is no change. Also I can close the needle and after about 1/2 turn in, it starts leaning out. So I don't think it is lean.
2. Also after running full throttle for several seconds, when I go back to idle it runs at a fast idle for 10 or so seconds then idles down to idle speed. Also with the butterfly fully closed it continues to run for a minute or so before dying.

Any ideas on these?

Thanks

fujiman

My Feedback: (133)

check for air leaks around carb base (o-ring), cracked carb. base gasket, and make sure the vent hole in the steel lid is not be effected by pressured in cowl air which can play havik with the operation of pump diapham. Mite have to solder in a tube and route a hose to go into fuse so venting the back of the diaphram can be in stable, nuetral air. The diaphram is very sensitive and must be vented properly. I think i mentioned that before earlier. what idle speed is the eng. running at???? trying to get a reliable idle some guys turn up the idle speed screw and this can lead to some idle/transition problems. It uncovers the second or low to mid-range spill port and when you try to compensate with the low mix screw all kinds of strange things can happen, fighting mid range/trans. problems, etc. try to get the BEST reliable lowest idle speed poss. you can leave glow driver when doing this to help eng from dying until you have the speed and idle mix sorted out and don't forget that the low/hi speed mix screws interact so you mite have to go back and forth a few times to get things rite. good luck and don't fly until you have total reliability. let us know how things work out. these walbros can be strange critters at times. the more you fiddle with them the more tricks you will learn!!!!

fabmaster911

I got ya. I just wondered because I paid $12.00 for a carb, $38.00 for an ignition and $70.00 for machine work and paid $75.00 for a brand new engine so i'm into it being a gasser for $195.00. Cheapest new gas engine I ever bought. What you guys are doing is also cool though.

fujiman

My Feedback: (133)

what tigre do you have?? tell us more details of your gas conversion.

fabmaster911

I had Ken Lambert do the conversion for me. The crankshaft has had a hardened pin installed and the rod has roller bearings installed. I am using a Walbro WT 529 carb. I have not run it yet but he started it for tuning purposes and it was spinning the heck out af a 18" prop. Unfortunately his Tach was on the blink and I didn't have a muffler so I don't have any numbers yet. I should have some within a week or so and i'll post them.

I actually paid a bit more for the ignition but now i've found the same ignition on Hobby King, Rcexl which is what just about everyone is running.

fujiman

My Feedback: (133)

would you share the link with us? I need 3 igns. systems myself. thanks a bunch

voodoodb

My Feedback: (98)

www.hobbycity.com

ScottMcM

My Feedback: (66)

Is there any collector value for a Super Tigre V .56? I just picked one up.

jay1st

Hi all !

New here and I actually own a low wing sports trainer powered by an ST 45 GS.

Very good engine, but the muffler weights tons and a friend has the same plane with 46AX and he is way faster than mine[>:]

Any good prop size for this engine ?

I am using an APC 11x6, tryied 10x7 but not satisfactory.

Tnx

NM2K

My Feedback: (14)

Encourage your ST G45 to rev way up. It is an ABC engine, after all.

A 10x6 prop is more in line with producing maximum horsepower. Horsepower and quiet are not compatible in most two-stroke glow engines. The older GS45 was designed during a time when power was paramount and noise was a secondary consideration. You will not hurt this engine by running it at higher rpms. The next thing that I would consider is finding a performance boosting muffler of some type, such as the ones produced by Jett Engineering and PSP, here in the USA. Another possibility, and especially if you need quiet, is to look into fitting the engine with a muffled tuned pipe. Quite often, the muffled tuned pipe is far quieter than the stock muffler.


Ed Cregger

jay1st

Tnx for the reply AJ4PJ

I am thinking of making a mousse can muffler type, no worries about the noise (some guys do Q500 training cessions ) .

So, a 10x6 will be better and no problem with high revs on this motor ? That's way cool.
I guess I have to go slighly richer (like pinching the tube to get a 200 rpm increase) not to over-heat the engine.

Everybody in the club uses OS engines (except racers), and I do fancy having something different than others.....