Castel Garden Mountfield ride on mower

[SirDick Diodenob esquire]

The driver had his head swivelled backwards instead of watching were he was going and hit a brick wall which has bent some parts and broken the front axle . I thought at first this would be an easy repair as at first sight it was just the original poor quality welding that had cracked off but unfortunately the pressed steel beam is kinked . I know I could buy a new one but I havnt got the £50 it will cost so it has to be fixed . The axle beam is made from 2mm thick steel , I have removed the top and bottom bosses and the grease nipple , inserting a 6 foot long 1 inch bar the axle has a lot of flexibility so bending it back to the correct position is proving difficult as it just springs back to the bent position . I am thinking of cutting off the upright stub axle tube and welding it back using a few small plates but its going to look a right mess but maybe thats the only way ? Also looks to me like the flexibility of the axle beam might be intentional by the makers or is just because its a crap design ?

 

[Wendelspanswick]

I would be tempted to force the part back together with clamps and tack the 2 halves together, apply heat to straighten and then weld fully once straight. Tacking the parts together might negate the spring back effect.
It would help if you have access to a Flypress or Hydraulic Press.

 

[FranV8]

I think if it was me I'd clamp the parts back together to get the fit up, weld it up well (looks like a stitch weld so I'd weld it fully) then go for straightening post welding but adding a bit of heat a few inches along the axle to encourage the bending to happen there.

 

[SirDick Diodenob esquire]

Thanks for replies , have eventually managed to tack it into what looks almost the correct position but main problem now is my arc welding skills or lack of them After nearly 40 years trying and having been on a welding course the best I can do with mma is weld 3mm+ so I am progressively destroying the mower axle tube blowing holes in it using approx 50 amps/2.5mm rods/ Lincoln Invertec , maybe I should try 1.6mm and less current ? I have decided to repair the old mig , much easier I think , even I should be able to use it but need some advice how to repair the wire speed control.

 

[Windy Miller]

Where in the UK are you?

 

[SirDick Diodenob esquire]

Hello Windy , I am in the back of beyond , the hills of Donegal , its probably quicker to drive to John O Groats than were I am .

 

[Windy Miller]

Hello Windy , I am in the back of beyond , the hills of Donegal , its probably quicker to drive to John O Groats than were I am .

Hmmm slightly too far away from me then!

 

[SirDick Diodenob esquire]

Con rod has made a hole in the engine

No sooner was the lawnmower back in action when it got stuck in a hole and the engine made a loud bang as it was working hard to get out . The engine now has a hole in the crankcase 3 inches wide by 1 inch high . Looking in through the hole I can see the crankshaft but no conrod , it seems to be missing but I am hoping its inside somewhere but I suppose it might have come out through the hole it made . I need to try and fix the hole , the crankcase could be made of cast aluminium , has anyone successfully welded one of these ? The engine is a Briggs&Stratton 12.5HP I/C made around 2002 but with only about 200 hours use . I was thinking if the hole cannot be welded about trying to make a cover plate and use silicon RTV gasket and drill and tap holes into the crank case , would this be a bad idea ? I can get a second hand piston and conrod for around £10 but maybe other parts will be damaged as well , has anyone seen this happen before on a lawnmower engine ?

 

[Moosevan]

I have an old 12 HP Briggs & Stratton engine sitting here in Hereford if you have any way of getting it over to you. I pulled it from a Westwood 1200S as it was knocking and blowing oil past the rings. Conrod & cases look to be ok. You're welcome to it if you want it. Must be easier than welding the cases.

 

[shenion]

I have had several of thos 12/12.5hp B&S engines throw a rod. TIG welded up the case and replaced the rod and they work fine. It is a bitch to do as the cases have some zinc or something that causes the weld to be porous. Often needs several passes of heat to boil it out.

The replacement rod is an updated one; apparently there were issues with the original ones.

Now, knocking is more serious, that is usually the bearings on the counterbalance weight journals. Not usually repairable.

The one I am working on now, I fixed the hole but noticed it was on the opposite side as normal. Just realized it had hit the camshaft an cracked both bosses (bearings) in the case. Will be a real pain to fix.

 

[SirDick Diodenob esquire]

Thanks for the offer Moosevan , if your crankcase is good it would be great , better than skipping my engine , will get back to you if I can get over from Ireland in the next 4 or 5 weeks .

Shenion , great advice thanks really appreciate it . The conrod has completely disapeared , the big end crankshaft surface from what I can see through the hole looks clean with no scoring but I will take the engine apart tommorow and see if anything else is damaged . Do you think that overfilling with oil could cause the conrod to break , I drained nearly 1.5L which I think is too much ?

 

[shenion]

These engines use an oil slinger. Too much oil or too little and they don't work. Think of the roostertail you see in the speed boat races.

I think these take about 1.5 quarts of oil; that's about 1.4L.

The crank will have aluminum fused to it from the old connecting rod. It is a pain to get off but I find muratic acid dissolves it right off. Keep acid away from all the rest though. Then I polish the journal with some compound and a buffing wheel.

This is what I found on an engine that was knocking:

Previous owner's kid mowed the yard with no oil. That rod and the broken boss are where the counterbalance pivot connected. The engine still ran The engine was shot as the crank was worn; the upper journal for the counterbalance got so sloppy that it twisted the pivot arm rod out of the case.

The one I am working on now, I drained about a pint of oil out of. I did tell the previous owner to check the oil more often.

 

[KemppiFrog]

I also have a spare 12hp I/C B&S engine you are welcome to, but even further away.

I recently fixed a much newer 16hp OHV for a mate. He is not very attentive about oil levels..... Not checked it for two years! To save hassle I bought a new short unit for £350 In the UK and bought it back to 'as new' condition (he is a contract gardener and was happy to spend the money)
While there was no hole in the case, there was quite a lot of damage inside from the bust rod thrashing about.

He also got a bit of advice about saving money as he has several other engines that were at risk.
KF