OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions on Other Engines Sanli Redback Ret Spring

Hi Everyone,

First time poster.
Have a Sanli Redback that is missing what I think is the return spring. Might be some bracketry missing as well. The problem is I have not been able to find a photo anywhere on the web showing the proper arrangement. I have attached a couple of photos but would love some advice on whats missing and where it goes? Surely someone out there must have a photo? Sanli and most of the dealers I have spoken to are next to useless.

Thanks in advance.

Very hard to know the Chondas vary so much from one to another

Hi Ausmow and Norm,

Some main butterfly throttles will open to the left and some to the right.

It's definitely missing brackets and linkages you can make them or just swap the parts from another mower.

They operate the same even if they look a little different.

Cheers
Max.

looking at that choke I think there is a good chance this has been left out in the weather or it has had ethanol fuel in it. I haven't seen the choke butterfly rusted like that before so something has been going on there

Looks like it's missing a spring.

I think the spring more than likely goes here but without seeing the length it's best guess.

On the other side of the brackets where you can't see the spring is where it goes .

Hi Norm yes that image you looked at was an old engine I left in the rain for scrap. It was just to show that linkage from another motor
could be swapped over.



Cheers
Max.

Hi Ausmow, Max and all. It's as max has it in the second pic. The anti oscillation spring is there and in it's correct place. The governor spring ids what's missing and it goes from the back to the loop in the linkage as max has highlighted.
It's a fairly light gauge spring as most of them are. Remember that this is a fixed speed machine so you'll have to make your own from another one and stretch or shorten as required to get it revving right.
The spring you require is NLA
Click the link below for a parts list/

Parts List

Hi Everyone,

Thanks for your help. Lovely knowing there are people willing to help out like this.

I will order the spring and let you all know how I go.

Thanks

Hi Everyone,

Long time between posts. Thanks to bigted I managed to get the correct spring and got the mower running. Since then it has been a constant battle to get it to rev right. Just when I think I have it nailed it changes as the mower warms up. Adjusting the springs and governor on the sanli seems to a bit of a dark art and a matter of minute adjustments. Any help appreciated.

Thanks Tim

Hi Tim,


It's easier if you put a mark on the governor first like in the image below.

Governor Arm Adjustment Procedure (Small Engine / Mower)

As you found out when loosening the governor arm clamp bolt on the governor shaft, the governor system allows very minute rotational adjustment. Small movements of the governor arm can result in noticeable RPM changes once the bolt is retightened.

Adjustment Notes

After repositioning the governor arm and tightening the clamp bolt, engine RPM will change based on how far the arm is rotated.

Because the adjustment range is small, it can be difficult to judge how much movement has occurred.

Recommended Marking Method

To make accurate and repeatable adjustments:

Before loosening the governor arm clamp bolt, use a scribe, small screwdriver, pick, or sharp knife.

Scribe a reference line across the end of the governor shaft and onto the governor arm, or along the side of the governor shaft if the governor arm sits a fair distance down from the end of the shaft.

This reference mark provides a visual indicator of the original position.
Note: The metal does not need to be scratched—applying a black marker (texta) first will make the reference line clearly visible.

Benefits

Allows you to clearly see how far the governor arm has been moved.

Makes fine RPM adjustments easier and more controlled.

Provides a reliable reference point for future governor adjustments.

Final Adjustment

After repositioning the governor arm:

Tighten the clamp bolt securely.

Start the engine and verify RPM.

If further adjustment is required, use the reference mark as a baseline for incremental changes.

Cheers
Max.

Hi Max,

Thanks for that. Took your advice and definitely has made it easier to reference the changes. I have managed to get it tuned to a good rpm again but the problem now is that after about 5 mins of mowing it starts to run rough and surge before stopping altogether.

Any thoughts? Tim

G'day Tim,

First thing I’d do, if you haven’t already, is take the fuel hose off the fuel tank. There’s usually a fuel filter strainer in the outlet of the tank. Sometimes you take the hose off and the filter is still in the end of the fuel hose. Then clean the filter and the tank out.

The carby has a fuel tap on it, sometimes I’ve had to push a wire into the fuel pipe inlet to dig the corrosion out, and then pull the fuel tap apart to clean the gunk out of it. Undo two screws and the fuel tap comes apart.

With fuel in the tank and the fuel bowl off and the float and needle removed you can check to make sure the fuel flow is correct.

With this, 5 mins of mowing it starts to run rough and surge before stopping altogether.

It's usually fuel or spark problem. Also you do the easiest fixes first like replacing the spark plug with a good known plug.A bad plug can fail when hot.

When a small petrol mower like a Sanli runs fine cold, then after ~5 minutes starts surging, running rough, and finally dies, that usually points to a heat- or fuel-delivery–related problem, not basic tuning.

Here are the most common causes, roughly in order of likelihood:

1. Fuel tank not venting (very common)

Symptom match:
Runs fine for a few minutes → fuel flow slowly stops → surging → stalls.

What happens:
If the fuel cap vent is blocked, a vacuum forms in the tank as fuel is used. After a few minutes, fuel can’t flow.

Quick test:

Next time it starts to surge, loosen the fuel cap slightly or remove cap.

If the engine smooths out or restarts immediately → blocked fuel cap vent

Fix:

Clean or replace fuel cap

Make sure vent hole isn’t clogged with dirt or grass

2. Partially blocked carburettor (main jet / emulsion tube)

Symptom match:

Runs OK at first

As demand increases and fuel level changes → leans out

Causes surging, hunting, then stalling

Why tuning “helped” temporarily:
Adjusting mixture can mask a blockage, but once warm and under load, the restriction shows again.

Fix:

Remove carburettor

Clean main jet, emulsion tube, and all passages with carb cleaner

Blow through with compressed air (don’t use wire)

3. Debris in fuel line or tank

Symptom match:

Debris floats around

After a few minutes it gets sucked into the fuel outlet

Engine starves, then stops

Debris floats away again → restarts later

Check:

Drain tank into a clear container

Look for dirt, rust flakes, plastic shavings

Check inline fuel filter (if fitted)

4. Ignition coil breaking down when hot

Symptom match:

Runs perfectly cold

Once hot → misfire, surging, stall

Often won’t restart until cooled

Test:

When it dies, immediately remove spark plug

Check for spark

No spark hot, spark returns when cool → coil failing

Fix:

Replace ignition coil

5. Blocked fuel cap pickup screen or carb bowl vent

Less common, but can cause:

Gradual leaning out

Surging under load

Stalling after several minutes

6. Overheating (less likely but possible)

If:

Cooling fins packed with grass

Flywheel shroud clogged

Check:

Remove top cover

Clean cylinder fins and flywheel area

Cheers
Max.