jadec241

My Feedback: (29)

I HAVE A NEW 17CC GAS ENGINE THAT IS RUNNING ROUGH. I CHECKED THE TIMMING & FOUND OUT IT WAS OFF 10DEG. I RESET IT AT 28DEG. IT RUNS STRONG BUT WHEN I CUT THE THROTLE DOWN TO A IDLE I CANNOT GET IT TO IDLE BEFORE IT STALLS. I CHANGED THE DIAMPHRAM IN THE CARB & RAN IT WITH A EXTERNALL FUEL TANK TO SEE IF IT WAS THE TANK OR FUEL LINES. STILL NO IDLE. ANY SUGESTIONS.

arobatx

Does the engine respond to low end needle tuning on the carb, or do adjustments to the low end seem to have no affect?

jadec241

My Feedback: (29)

THE HI END IS ALMOST CLOSED & THE LOW END IS OPEN ABOUT ONE TURN.

jadec241

My Feedback: (29)

THE ORIGINAL CARB HAD A 28 VENTURI & I EVEN TRIED IT WITH A SMALLER CARB WITH A 20 VENTURI.. SAME PROBLEM.

Tired Old Man

My Feedback: (1)

WHY ARE YOU YELLING AT EVERYONE?

START WITH NEEDLE ADJUSTMENTS. YOURS ARE WAAAAY OFF.

jadec241

My Feedback: (29)

The settings on my 35 & 52 Quadras are set at 1 1/2 turns ea. on low & high end. Seams ok on them . What settings do you recommend on the 17cc for low & high.

arobatx

Is this a conversion engine? Will it start and run at all with both needles open 1 to 1-1/2 turns? If so, carefully lean the low end needle first, while adjusting your idle lower, and lower with the TX or linkage on a stand. You will reach a point where you can no longer increase the idle rpm with low needle adjustment. See if you can reach a decent idle at all, then open it back up just enough to get you a smooth transition...and adjust the high end needle from there. Small tweaks at either end should get you settled in, with some time on it. Somewhere along that road, there will be clues as to what the engine needs, that it isn't getting.

a1pcfixer

My Feedback: (7)

Nobody can tell you the exact settings, as you need to tune your gas engines for where you live.

First off, get it fully warmed up, THEN start your tuning the LS/HS needles.

See these for how to tune.....
Jody's gas engine tuning tips (pdf files);
http://www.rcuniverse.com/forum/fb.asp?m=10293852

jadec241

My Feedback: (29)

This is a SK 17cc gasser. SK used to be Tiger Shark. They have some pretty good glow engines. I am running a 1.20 glow engine on
FAI fuel. No nitro but 18% oil. it is alot cheaper than fuel with nitro. About $9.00 a galon.
The needle settings you say sounds about right. The low & high end might be to low & are not open enough to get gas. When I run it
at the low setting I get good responce. Will go back to the original settings & go from there.

michaelchow

maybe leak on cylinder head, reassemble.

aussiesteve

When you say it won't idle before it stalls, What idle speed are you trying to achieve?


SK = SuperKraft (AKA Kangke, Tigershark, JBA, Revolution and quite a few others).
Their more recent "Designer" (That would be the person who made the post above this one) now "manufactures" NGH. Pretty much all the gassers in those brands have Carb matching issues - either oversized or general poor performance. This is largely due to the current penchant for buyers to want to see MAx RPM on the ground with no real consideration about power curves or performance in the mid range where we actually fly.

If the needles need to be wound in so far and the ignition timing is right, you have one of 2 likely problems.
A carb diaphragm / spring / metering needle issue - or
A poorly matched carb.

It is likely to be either on any engine from those stables.


Make sure the spark plug is good (what are you actually running?)
Make sure your ignition battery is charged (this can show up this way occassionally)
Get yourself a can of WD 40, Start the engine and squirt the WD 40 at all joints. IF there is an air leak, the engine note will change while you are spraying at the joint and the engine will suck the WD 40 in. (I doubt it is an air leak in this case).

If all the above is good either send it back for replacement / refund - OR
Take the cover off the metering diaphragm (the cover with the 4 screws), check the needle height, check the needle itself and the seat do not contain foreign matter, reassemble according the the Walbro list, reset both needles to 1 1/2 turn open and start all over again.

jadec241

My Feedback: (29)

I am trying to achieve a low idle(not sure of the rpm's). The plug is a CM6 NGK. I changed the carb since I felt the one that came with the engine was way to big, #28 on the venturi throat. On my 52cc Quadra I am using a #28 venturi & that is what was on the 17cc. I put a #20 on which is alot smaller but it ran the same. Next I changed the diamphram. I am going to hook up a external tank & new fuel lines to see if it might have a air leak. The idea of using WD40 sounds good. That is my same thoughts that there might be a air leak somewhere since it runs smooth on a full throtle but dies when you try to let it idle.

michaelchow

I am wonderring where you bought from and who make it.

jadec241

My Feedback: (29)

Michaelchow, this is a SV-17 cc gas engine I bought several months ago on EBay. I no longer have the paperwork from it. I am still inclinded to think it might have a air leak somewhere. I am going to use some WD-40 around the seals later today. Will keep you informed.

fco_herrera

My Feedback: (25)

I have the same issue with one of this engines
i bought from a guy that shows the engine in Youtube, he says it was a new engine and it is not!
have many problems with the carburator and is impossible to maintein idle and WOT
i bought the repair carburator kit to try to fix any issues
let see what happens

jadec241

My Feedback: (29)

I changed the carb to a smaller Walbro. Checked the timming,it was off 8Deg. Check the timming, set the carb at 1 1/2 on the low & high end. I fired mine up today & it seems to run alot better. Let me know the outcome.

michaelchow

SV ≠ SK

jadec241

My Feedback: (29)

I was mistaken. The box reads SV-17. No other manufacters name on it.

fco_herrera

My Feedback: (25)

change carburator kit, set lever to walbro recomendation, check for leaks, try to start, it did start but I cant get it to iddle and transition is poor, WOT is fine, dont know what else I could do?

any recomendations ...while I try to go from iddle to WOT the engine bogging down and stop

jadec241

My Feedback: (29)

Do you know how to check the timing? Make sure it is set at 28 Deg. Mine was off, reset it, opened the low & high end 1 1/2 turns

then went from there. Mine still isn't 100% yet but its close. Open both needles more & try from there.