McCulloch 250 LS Strimmer - No Drive

[luap2411]

Hi All

After a bit of advice to see if anyone has had this issue and how they fixed it.

Strimmer is pretty old now, maybe 8 years. This year I dug it out of the garage and fired it up, ran fine for 20 mins. Then lost drive to the head. I can feel by turning the head there is no resistance (compression from the engine).

This model has the two piece shaft, the lower one is cranked down at about 45 deg. I've pulled the two shafts out, the inners are not broken, but have maybe 15mm each of float. So think the problem is due to float the male/female connection can disengage. Shafts cannot be disassembled, float is governed by plastic plugs inside the outer shaft. Was thinking of shimming the float out with washers on the male end.

Otherwise strimmer is OK, hate to throw it away, but the two shafts are 80 quid and not worth that to repair.

Anyone had this and found a fix - Thanks Paul

 

[Burnerman]

Can you remove the flexible drive cable out completely, and see that each end is squared?
Id suspect a cable fracture at the engine end.
John

 

[luap2411]

Yes, have checked, end are square, no evidence of rounding off at all. If I split the 2 piece shaft have lots of float. Re-assemble, get drive, then looses it again. Inner shafts not broken. It's annoying the heck out of me..... The plastic bushes that sit inside the outer shaft seem to regulate the float of the inner. Both in the top and bottom shaft this seems excessive to me.

 

[Burnerman]

The plastic bushes are there to centralise the drive cable and I think they would have to be very seriously worn or indeed missing altogether for the drive to fail.
It does sound like something has disconnected in the drive train somewhere or the shafts arent pushed back together fully.
I wouldn’t expect the drive shaft ends to be rounded off but is it possible that one end has sheared?
Since you seem to have covered almost everything drive shaft wise, maybe its time to check out the spool and engine connection at the other end.
John

 

[luap2411]

Thanks John. Motor side seems good but will double check tomorrow. Head has been removed and is fine there. It's not had excessive use even though it's getting on a bit. I thought it was either one of the bushes had dislodged (no way to relocate it as shaft cannot be stripped), hence the thought of shimming with small washers to reduce the float in the male end of the inners. Or, the fixing to lock the 2 parts of the shaft together isn't seating, so allowing play. Again will have another look tomorrow.

I knew it was a cheapie when I bought it, and expected much less from it. But to be fair it's been good and would just like another year or two before I buy something better. Especially at the moment as the oil boiler terminally bit the dust this week and that's not cheap !

 

[luap2411]

Well, I've got an update on this, so just posting to help anyone else that has the same issue. Basically problem was strimmer kept loosing drive, it's the type with the split two piece shaft. So the problem turned out to be a combination of wear and float in the inner drive shafts. The wear in the bottom bush on the lower shaft was causing just enough float for the inner shafts to disengage. That part cannot be stripped to repair. So, solution was to close up the float in the upper shaft by the motor. To do this I measured the exposed inner shaft protruding from the outer shaft at the motor end, it was 30mm. I tapped the shaft gently with a hammer to close this to 20mm, and packed out the inner shaft with about 8 small washers to take up the play. It's not a perfect fix, but it works for now, and can hopefully extend out the life for a year or two.

Next job, the leaking boiler.....

 

[Khybre]

Well, I've got an update on this, so just posting to help anyone else that has the same issue. Basically problem was strimmer kept loosing drive, it's the type with the split two piece shaft. So the problem turned out to be a combination of wear and float in the inner drive shafts. The wear in the bottom bush on the lower shaft was causing just enough float for the inner shafts to disengage. That part cannot be stripped to repair. So, solution was to close up the float in the upper shaft by the motor. To do this I measured the exposed inner shaft protruding from the outer shaft at the motor end, it was 30mm. I tapped the shaft gently with a hammer to close this to 20mm, and packed out the inner shaft with about 8 small washers to take up the play. It's not a perfect fix, but it works for now, and can hopefully extend out the life for a year or two.

Next job, the leaking boiler.....

Well, I'm super late to the party but I wanted to ask a few questions regarding the fix.

Can you elaborate a little more on how you actually fixed it?
I have tried closing the gap at the motor end of the shaft but I can't seem to get it to move at all?