super tiger 61, keeps cutting out, need help

[joey]

Hi guys, I have a super tiger .61, with a tuned pipe on it. I placed my engine in my test stand today, and after a long period of time, I am able to get a beautifull low idle, it just purrs, but when it comes time to give it a good shot to full speed, it just sputters, and dies at about 1/2 throttle.I tried to go out and in with the high speed needle valve, but it didnt seem to make any difference. I am using brand new 10% fuel, new glow plug, and I checked for air leaks, at the tank and in the lines, but I didnt see any. If you guys have any tips or hints, I sure would like to hear them. I started getting frustrated, so it went back in the garage till tomorow. any ways, thanks guys, hope to hear from you,,, Joey.....

[Propworn]

What glo plug you using??

[xv-townboy]

your low speed needle,i think is your problem

[AJCoholic]

If it sputters and spits fuel out the carb, definitely rich on the low end. If it dies suddenly too lean but sputtering tome sounds like a rich low end, loading up when you try and transition too quickly.

[joey]

thanks for the replys, I will try to lean out the low end needle valve today, but I was allways under the impression, that if your engine is idling really smoothly, then your low end needle valve is o.k., I will let you know how I made out. thanks for the help.... Joey....

[JimBrown]

I was allways under the impression, that if your engine is idling really smoothly, then your low end needle valve is o.k.

Gotta remember, not all engines are the same. :roll:

Some engines will have a smooth idle over a fairly wide low end range. As you've found out, if the low end is at one of the extremes of that range, transition to full throttle may be a problem.

Before setting the low end, I set the high end to max RPM, then richen three or four clicks. Then, to set my low end needle, I let it idle for at least one minute, then quickly go to full throttle. If the engine sputters at all, the low end is too rich so I lean it just a wee little bit and try again. If the engine just dies without sputtering, it's too lean so I richen it just a wee little bit and try again.

It can be a pain to test, stop, adjust, start and test many times. However, it is worth that pain once it is set. And, you shouldn't have to set it again for the entire season.

Hope this helps,
...jim

[JimBrown]

If the engine sputters at all, the low end is too rich so I lean it just a wee little bit and try again. If the engine just dies without sputtering, it's too lean so I richen it just a wee little bit and try again.


Hmmm... I just reread this, and it needs a bit of clarification.

If the engine sputters and dies OR sputters and then picks up, it is too rich.

If the engine just dies OR sags without sputtering before picking up OR takes a while to pick up without sputtering, then it is too lean.

...jim

[Propworn]

The Super Tiger carb is just a little different than most other carbs. The high-speed needle controls the fuel flow at wide-open throttle the same as every other carb. The low speed however extends inside the fuel spray bar and works by partially blocking the cats� eye slit in the fuel spray bar. As the drum is rotated the low speed needle adjusts its position inside the spray bar to regulate the fuel at idle and mid range. Mid range can also be adjusted somewhat by the rotation of the spray bar and the cats eye slit in the spray bar.

First lets start at the beginning.

Set up of idle screw. Close the high speed then open 2 and � turns. Use a short 6-inch piece of fuel tubing and put on end over the fuel inlet. Use a pin (t-pin or building pin) and close the throttle barrel until it just contacts the pin. Roughly 1/16 of an opening of the carb. Now blow through the tube and close the low speed until no air will pass. Slowly open till air will just pass. Now open � to � turn more. Your low speed is set to factory specs.

Replace the glo plug with a Hanger 9 HAN 3000 performance two-stroke plug. These may have been discontinued so use the HAN 3006 or the Heli performance plugs HAN 3020. One other trick is to take a small screwdriver and pull the element so that it is slightly extended beyond the base of the plug.

Start the engine and set the high speed. You can use the pinch and release method here. Pinch and release the fuel line. If engine sags or dies you are to lean if it speeds up its too rich. Do it a few times to confirm the result. No rpm increase indicates this is as lean as you want to go. Some will open the high speed till a very slight rpm drop is noticed and that�s about it.

Set the low speed as you would any other engine. If the mid range is a little off try rotating the spray bar and cats eye by loosening the two screws that hold it in the carb on the high speed side. Rotating the cats eye will change the mid range.

Using the pinch test check the top end rpm often as some of these changes may effect the top end as well.

Hope this helps

Dennis

[joey]

thanks for all the input guys, propworm, that was a great idea,(about the low speed needle set up) I tried it and it really helped, it is almost perfect, I think I stilll have to do some small adjustments, but it certainly is alot better than it was, thanks to all who helped....Joey....