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-   -   Super Tigre 75 with a YS Carb (https://www.rcuniverse.com/forum/questions-answers-154/5320998-super-tigre-75-ys-carb.html)

secret_squirrel 01-25-2007 11:42 AM

Super Tigre 75 with a YS Carb
 
All,

I have an old Super Tigre 75 that a friend at my local flying field handed me as a gift. It has a YS carb and I have never owned an engine with a YS carb. For fun the other night I mounted it to one of planes to see if it even cranked. I never expected much of the engine but had some spare time. To my surprise it started and idled pretty good. The needle assemble on the carb looks pretty familar except at the bottom of the needle valve there is a large metel wheel (approximately 1/2 in diameter). I am guessing this is the low end adjustment but it doesn't seem to do much.

After I started the engine and adjusted the high end, I ran it up. It runs up nice but then at full power the engine suddenly cuts out. It cuts out very quickly after reaching top speed. No matter what I do to the high end adjustment it has no effect.

Any thouhts.

TIA,
Dan

firstplaceaviator 01-25-2007 01:14 PM

RE: Super Tigre 75 with a YS Carb
 
The YS is a pressure carb. It is designed to work with a pressurized fuel system. Without a pump, it will cut out suddenly at higher throttle settings.
You could try a Perry VP-30 pump and a one way check valve on your muffler pressure tap. That should do the trick.
The pump will feed constant pressure to the carb, while muffler pressure will pressurize the fuel tank and feed the pump.
Or, take the easy way out and buy the correct carb for that engine.
Doug

secret_squirrel 01-28-2007 11:09 PM

RE: Super Tigre 75 with a YS Carb
 

ORIGINAL: firstplaceaviator

The YS is a pressure carb. It is designed to work with a pressurized fuel system. Without a pump, it will cut out suddenly at higher throttle settings.
You could try a Perry VP-30 pump and a one way check valve on your muffler pressure tap. That should do the trick.
The pump will feed constant pressure to the carb, while muffler pressure will pressurize the fuel tank and feed the pump.
Or, take the easy way out and buy the correct carb for that engine.
Doug
What is the small kmetal wheel at the bottom of the high end needle valve? Is this the low end. It never stops turning in either direction to indicate closed or wide open. All it seems to do is change the direction of the fuel mist inside the carb??? I talked with the guy who gave me the engine this weekend and he said he had it running. I came home and messed with it and have gotten close but it isn't there yet. Will it absolutely not run good w/o a pump?

I really think it has something to do with that wheel but I can't for the life of me figure out what it does.

Any further help would be greatly appreciated.

Dan

firstplaceaviator 01-29-2007 12:23 AM

RE: Super Tigre 75 with a YS Carb
 
Dan,
I wish I could help you here. But, I am not familiar with that particular carb. I have owned several YS's and still run YS's in my heli's. But, I have never seen the wheel that you mention. I have had a YS .45 and a YS .61 in planes. I currently fly a YS .61 an .80 and a .90 in my helis. Both of the plane engines only had a high end needle. The low end was set at the pump diaphram on the bottom of the engine! As a mtter of fact, I can't even imagine how you could mount a YS carb to a Supertiger. The YS bolts to the crankcase in completely different fasion than the Super Tiger! The wheel you are describing sounds like a Perry carb. Could you post a pic?
Doug

secret_squirrel 01-29-2007 06:43 AM

RE: Super Tigre 75 with a YS Carb
 
The carb is JB welded to the engine. I just woke up and don't have any pics. I will try and get some later. After a good night sleep I am thinking I just need to bite the bullet and buy a carb for it from tower. My concern is after I spend $35.00 on a carb will it run?

secret_squirrel 01-29-2007 09:32 PM

RE: Super Tigre 75 with a YS Carb
 
1 Attachment(s)
here are the pics

secret_squirrel 01-29-2007 09:33 PM

RE: Super Tigre 75 with a YS Carb
 
1 Attachment(s)
pic 2

secret_squirrel 01-29-2007 09:34 PM

RE: Super Tigre 75 with a YS Carb
 
1 Attachment(s)
pic 3

firstplaceaviator 01-29-2007 09:59 PM

RE: Super Tigre 75 with a YS Carb
 
Well Dan,
I'm stumped! I have never seen that carb before! Maybe another expert will chime in here and help you out.
I'm kind of surprised that no one else has even posted in this thread. Perhaps you should re-post it in the glow engnines forum.
Sorry I couldn't help with this carb. But, I am willing to bet that the engine would run just fine on the proper Super Tigre carb!
Doug

secret_squirrel 01-29-2007 10:16 PM

RE: Super Tigre 75 with a YS Carb
 
Ordered one this morning. I like to fix stuff but if I spend more than a couple hours doing it well then it becomes a waste of time. I am almost positive the carb says YS on it. Anyway, appreciate the help. If the Super Tigre carb from Tower doesn't work I'll be back. Just hope I can get that JB Weld off w/o damaging the case.


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