OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Trimmers and Brushcutters Ryobi Trimmers & Brushcutters 2 Grass Scorpions can't get either to work

I have 2 Grass Scorpions, oldish machines and both made in Usa. They don't have an ignition switch. No 1, changed all the fuel lines as well as primer bulb, cleaned carby out, diaphragm and gaskets in pretty good condition so gave them a clean. Machine starts in partial choke but dies instantly. Check the spark plug and if anything it's a little wet so assume petrol getting there.
No 2, been sitting around for years, removed most of old petrol/oil residue as per Big Ted and Grumpy's instructions. Replaced one perished fuel line. Has only fired up once and died immediately. Checked spark plug and it looks wet. Tested spark plug on trimmer's chassis and still plenty of spark.
I'd like to get at least 1 of these to work, can anyone give me some advice please?

full choke they kick ..... half choke kick a splutter ? try no choke sounds as if flooded ?? just normal starting things ,
full choke and a kick , half choke a little run but throttle and it will . then as it warms up just off choke slowly ? and then maybe it should run and clear up , lot of smoke but then allgood , see how ya go tiger

G'day Dave. Did some more work on no 1, another carby clean, replaced all gaskets and the diaphragm. Runs better but cannot run on no choke, motor just dies. How do I get this to run on no choke the way it should?

Thats the question that has boggled man for years...lol
Sound like a lean/fuel starvation issue. I won't get into nitty gritty around carb rebuilds as i just don't bother or have the patience for trimmers anymore but since you've already cleaned the carbs, try replacing/removing the fuel filter if you haven't already done so. If its blocked it wil give your symptoms.

Thanks Ted, the fuel filter is about the only thing I haven't replaced.

good tip , heaps of them here too in a pile hahaha just cant be bothered and hard to sell if you can get a new one now for $80

Dave, give yourself a real challenge instead of working on those simple mowers and try one of those whipper snippers. The older ones made in the USA aren't too bad but most of them will not run on no choke after a short while, agree with Ted that there's probably a fuel starvation problem, just not sure where though.

hahahaha ok , thanks for the advice , i do fix them though , just don't enjoy it as much , to much time for little return

Aah yes, but think of the satisfaction when you get one to work, money can't buy that.

The best thing about that satisfaction is you get to have it over and over again, when the buyers keep returning them.

Not only do they return them Grumpy, they expect the $20 they gave for it to include a 12 month warranty.

hahahha so true it is !!! hence why most don't bother , just keep the ones i use up n running is enough , temperamental little trinkets they are

Grumpy are you talking specifically about whipper snippers? Why do these things break down, is it due to poor maintenance like leaving fuel in them or have they got crappy carbys? When they don't run or run poorly it's because of fuel issues, I would have thought manufacturers would have caught on by now and improved their products but I do understand they make things to a price.

Thing is if Ryobi was to make top quality whipper snippers people wouldn't have to keep buying them over and over again. There isn't enough money in quality products most of the time these days. We live in a disposable society - No-one wants to spend $500 on a whippersnipper they will use once every 6 months when they can spend $80. Different kettle of fish for commercial equipment of course.

I find the biggest issue is and always has been poor maintenance. The trimmer heads especially followed very closely by the carby - people fill a 5L can with 2 stroke, fill the tank from it once and leave it in the shed. They only use a tenth of the tank before the fuel breaks down and it blocks the jets.

The carbies are so small that the jets are tiny and I cannot see (I have quite severe sight issues) what I'm doing so it can take around 5 hours for me to properly clean out a carby and then spend another hour or so trying to get the mixtures right.

I never bother with whipper snippers. When I get brought one for repair I usually just talk them into selling it for scrap metal and buy another one.

My 2 cents worth.

Pete

Good points I hate wet socks I'd forgotten about the heads on those trimmers. In regards to the tiny jets , what about using an ultrasonic cleaner? I don't have one but seen some good reviews on them. By the way what are they worth in scrap value?

I suppose an ultrasonic cleaner would do an OK job but the problem of the diaphragm tearing and the mixture screws remains. As for scrap value ... unless you live next door to a scrap yard you'll spend more on petrol driving there.

Pete

Tiger, I was talking about a particular grade of whipper snipper, not all of them. Some of them have features such as half-cranks and tin-pot kill switches that make them both unreliable and unpleasant to use. Also, I do not regard the carburetors as one of the sub-standard parts of them. They do give carburetor problems, but those are often due to abuse (usually dirty fuel) or just the limited life of diaphragms.

It also seems to me that even fairly decent bent-shaft whipper snippers usually have rather short lives due to lack of lubrication of the bottom bearing of the inner cable, and crummy feed spools.

Beyond that, it is mainly a problem of them being too fiddly and sensitive to be usable by the people who are the target market for them. Many owners will not measure the amount of oil they add to the fuel (if they add any oil), or keep dirt out of the fuel tank, or wind the line onto the spool properly, or even put them under cover when they don't use them for a few months. I have one that had its bell-housing broken in half after a very short period of use because the owner chose to kneel on it while he pulled the starter cord. Since we can't change the people who use them, the only sensible approach is to make them so that those people can use them successfully. Both Briggs and Honda have taken that approach, with reasonable success.

Ok, thanks Grumpy for clarifying.

These have sat in the shed for a year, time to fix or out they go.
No. 1 seems to flood easily. Did get it to start, fiddled with carb adjustment screws and it ran well. 5 mins later, won't work. Looks flooded. Also the fuel lines have either stretched or weren't right but that's what mower shop sold me. There is a small leak at where they join onto the carby. Not sure I have the fuel configuration right.
No. 2 still feels rough to pull cord and now the primer button has cracked. Put a bit of time into machine 1 and hope to get that going at the very least.

Photo 1 and 2 show no. 1 whipper snipper, photos 3 and 4 show no. 2. One of these machines has a Walbro, the other Zama.

First the flooding is likely caused by harden metering diaphragm.

Second on the fuel lines the 2.5mm x 5mm rubber (Echo)is probably the line to go with. Shop sometime will sell line that simply will not fit the carburetor fitting tightly trying to get a good tight tank fit. An alternative is to use tag wire and wrap a couple loops the line at the fitting and tighten. Poor man clamp.

On second trimmer with primer well that primer replacement is at least a starting point.

I take it you replaced the fuel pick up filters at the same time as the hose? That is a common problem with most that have been sitting around as the fuel goes gummy inside the filter even though it may look alright from the outside.

Thanks AVB, very helpful and suspect you're right regarding the hardened metering diaphragm, took it out last night and it was a little stiff. The pump diaphragm was soft and malleable though. I've got a mityvac pressure tester and tested the carb in water and there were some bubbles coming from the metering diaphragm end, not many but they were there. I also took the little mesh gauze out as I have seen from previous posts that that may help. The machine starts but will only keep running if I press the throttle down. Starts easily enough but won't keep running.
Machine 2 will need a new primer button and I'll install it when I get a chance. Would like to get at least no.1 going.

Hi Trev, fuel filters changed.

What do you mean by "press the throttle down?" Since you said they don't have an on/off switch I assume they have a kill wire built into the throttle position somewhere much like a mower carby. Could that be a possibility as to why it will only run with the throttle pressed? Are you sure there is a good seal between the carby and the motor?

Throttle/trigger to increase the revs. The default power setting on these is on, the throttle is a separate function.

Last year I cleaned up a hoarders house after he died.He was a motor mechanic, 14 cars around the house, sheds full to the roof with car parts, the house was about the same with just walkways between all the stuff. In there was probably 40 wipper snippers, they all went straight in the scrap bin, had no idea if they worked or not, was not worth even looking at them

I with you norm scorpion whipper snipper not worth fix buy new home use one cheap less $100 bunnings .they ment to be throw away. mowershop wont bother to even look to fix.you maybe spent hours trying to fix not worth your time, buy new one

i guess it's the challenge of trying to fix them that keeps me going, agree not in it for the money.

Tiger, I understand where you are coming from but those little suckers can become so frustrating

Frustrating they are. I've got 4 Ryobis that I've had for some time. I can get them all to start but none run on zero choke. I assume it's fuel related but most of the carbys have been cleaned and had diaphragms replaced. I know the compression is ok, spark is ok. I have to assume there is an air leak but I can't work out where? I did read that the gaskets on the crankcase fail after a few years on whipper snippers, I guess a last resort is to buy some gasket material and make up some new gaskets. Other possibility is to try a brand new carby but I can't find a direct equivalent to what I have. Did ring one mower shop who said they could sell me a 2nd hand Ryobi carby for $35. They are pretty sure that it was working when they stripped the machine down.

I wouldn't try getting a gasket, thats if they do have one, a thin smear of 518 Loctite is all it would need. I have a Ryobi whipper snipper had it for 10 years or more, only used it half a dozen times but it runs fine and crank seal is still ok

Thanks Norm, do you unscrew the crankcase halves and apply it or is it sufficient to just smear it on the join?

Tiger, if you a convinced the gasket is a problem and you want to reseal it then yes you would need to split the cases. What I did with an old Enfield twin a couple of years ago was to go around the crankcase join with a hacksaw blade and dug a small grove around it and then put a bead of JB Weld in the grove and that was enough to seal the cases up and stop the oil weaping out. Could be worth trying but personally I doubt that would be your problem