Muddy42

I would stop using that for risk damaging the saw. Do you not still have the original one to put back on?

Agreed. Always pressure and vac test.

I can’t say I can hear the rumbling noise, but maybe that’s the audio. I think I can hear the high pitched rattle sound of worn clutch springs though?

It also helps if the saw wasn't running when it gets dunked.

The only times 120cc is worth it is where weight doesn't really matter and you need lots of power - milling or chunking up massive logs on the ground. I don't climb but I can't imagine that would be great.

So many different views! Sorry if you know this, but be aware that 881s have a totally different bar mount from your 500i. Personally I think 120cc is the only way to go if: - Doing any milling at all. Yes you get people saying you can get away with 70-90cc, but its so much easier and quicker with 120cc saw. - using any bar above 40 inches

I have an 088 (also 120cc) with 25/36/54 inch bars. My next biggest saw is an MS460 with a 20 inch bar (so a bit smaller than your 500i). With the 088, I mill, crosscut and block up big logs with it. Its great for all three of these tasks. I only mill with the 36 inch bar - which is ideal for one person milling of say <30 inch timber. I have owned the 54 inch bar for a few years but havn't really had the timber to use it yet. For crosscutting and blocking up big lumps of hardwood, the 25 inch bar gets a lot of use. I do prefer a 120 cc saw to a 70-90 ccs for this hard task. The extra weight of saw isn't really an issue when you are kneeling on the ground. I occasionally use the 36inch bar for crosscutting massive logs. I have to say, its pretty scary and unwieldy to use without the protection of the mill. For example, if you put the saw down, the bar is front heavy and can dig into the ground. All chains are normal (not skip) 30 degree ground semi chisel. I don't find rip chain makes a difference in hardwood and my 30 degree sharpening muscle memory is hard to overcome.

Thanks for the support Mick. I am gearing myself up to just go for it. Lots to learn and nothing to lose apart from elbow/hand grease and the cost of parts.

or more likely second hand from a wreckers yard.

Been doing some research. Maybe I can get some more oomph out of the starter motor, but I think there is a high chance the compression release lug has exploded on the camshaft and bits of metal are floating around the sump. This seems to be a fairly common that B&S engines are hard to turn over. My local B&S workshop says replacing the camshaft would be a major job and I should scrap it. Of course I have the option of DIY, with just the cost of parts and gaskets, but this would be a fairly ambitious undertaking for me! I suppose if I fail and it ends up as scrap I have only lost the cost of the parts (that's how I normally gear myself up for irrational repairs to old wreaks!) I have contemplated rigging up two batteries in parallel, to achieve the amps required to start it. I know this works by jumping from the car. However there is a risk that lumps of metal end up causing a lot of internal damage.

50:50 sounds strong to me. Ive not used jays fluid on trees, but its pungent! Ive used general purpose insecticide/fungacide with great success on a few sick trees. Also in this weather, I would also feed and water the tree.

I agree with the negatively around cone splitters on smaller machines or loaders. They really only come into their own on 20+ tonne diggers and a large scale operation. Ive seen one splitting a stack of >2ft wide trees ready for the log processor in no time. This was done in advance of the processor because its so quick, whole trees get split lengthways. I think you can get cone spliters with a grab incorporated, but I've not seen one in action.

Yup that's right, thick red wires from the battery to the solanoid and then straight to the starter, earthed via the chassis. Not many connections to go bad. I can turn the flywheel by hand, so I feel the starter motor should be able to cope.

OK, thanks. So the mower's battery (at 310CCA) should be enough. Sounds like its worth cleaning inside the starter motor. I've never looked at this and the mower must be 35/40 years old. I'm keen to try all the fixes that are free before looking for new parts.

Thanks. I will do clean the clutch if I get the engine running smoothly. I replaced the solanoid two years ago. Yes, I've shorted the two solanoid terminals and I get the same result. When you say "not a 4 litre Perkins!", are you saying that 310 CCA, should be more than enough?

Thanks Gareth. Sorry I may have muddled things. The battery on the mower is brand new - 12v and 310 CCA. It turns the engine a bit with difficulty but doesn't start it. I was replacing a battery that was 10 years old and 12v and 300 CCA. Actually the old battery doesn't seem perform much worse than the new one - I trickle charge the batteries a few times over the winter. No idea what CCA the car battery will have, but many more. The car battery did jump the engine though. I've checked and brightened up all the electrical connections. Maybe I'll take apart and clean the starter motor aswell.

OK so wee update to this. Using my multimeter and lots of continuity checking, I worked out that one of the safety cut-offs was interfering with the operation of the PTO circuit, so I've stripped the wiring right back to basics - no dash lights, no sensors, no headlights. Now its basically the same as the attached Briggs & Stratton wiring diagram (but plus the two belt controls - drive and PTO). However now the engine was having starting problems and was hard to turn over. I wondered if the PTO might be siezed or causing extra engine load, as a related issue. I loosened off the PTO completely and cleaning it out with a pressure washer, then dried, then WD40. The PTO was showing an electrical resistance of 3 ohms, which internet says is fine and it clicked on and off when hotwired. After this the PTO seems to turn freely, so I concluded that wasn't the issue. So I turned to the V-twin engine. It was still hard to turn over. I could start it when jumping it from the car, but not from the 12v battery (which is a new mower battery by the way). But I guess the car provides 48 amps rather than 32?? I don't have a feeler gauge, but the engine's valves didn't seem too tight. When rotating the engine, I couldn't see/hear the operation of a compression release. So I'm a bit stumped really. Could it be a weak starter motor or some major issue with the camshaft and compression release? Im just going to leave this post here and see if anyone has any bright ideas, while I do some more reading. The engine is a Briggs and Stratton 16HP V-Twin model number 303777.

Thanks yes, I'll give that a go. I see a few hours ahead of me with the multi-meter and some replacement wire and switches! I don't think its the clutch itself, but I'll give everything a clean up and check just in case. The whole clutch looks removable. I had a lose oil filter last summer, so everything is covered in oil down there. Thanks

Ive ordered a multimeter to see whats going on behind the pto switch.

I have been trying to run my 1990s Bolens ride on lawn tractor. It has a Briggs and Stratton 16 HP Vanguard V twin engine. The engine has PTO/clutch below it that is electrically driven - flick a switch on the dash and the PTO should engage underneath the engine. Then the PTO would drive the cutting deck via a belt. However, as you'll see in the video below, when I engage the switch the engine just dies. The machine itself drives backwards and forwards fine. Please note, the cutting deck is totally removed for safety. I have tried disconnecting the wires to the PTO and I get the same result, which makes me think the issue is electrical rather than something mechanical in the PTO itself. I have bypassed various safety switches (seat etc.) but I think either there is another safety cut-off or the switch on the dash is faulty. Annoyingly there arn't any markings for the PTO switch on the dash to help me. Is it OK to test the PTO by wiring it directly to the battery? Any if this works can I just fit its own switch and circuit? Thanks, IMG_7918.MOV

My understanding is that Husquvarna have the best anti-vibe and the pro brushcutters are all good. I think it goes approximately 525 (25cc) 535 (35cc) 545 (45cc) and 555 (53cc). It depends what you are cutting, but I find 25cc underpowered for anything but lawns and 53cc is heavy going. Honda do 25cc and a 35cc fourstrokes. However I've never really clicked with them - they are heavy for the power you get and the revs and power are just different. Plus I am less familiar with the engines for repairs.

Oil ratios are a contentious topic, very hard to test or prove one way or the other! Personally I use 40:1 across everything whether old or new machines, milling or crosscutting, using aspen or pump fuel. I tune the older saws for this. I also believe the USA environmental push for 50:1 and I am just a fan of oil. I have a friendly mechanic that has been repairing saws for years (he does bearings and rebuilds for me) who insists on 40:1, so that's what I do. The infrequently used machines run on aspen and I don't so anything special before putting away. The strimmers drink a tank of aspen before being run dry and stored. My goto Stihl 261 uses pump fuel and gets used daily.

Yup, totally agree, if you have a larger saw, that's the way to go. For me its a MS 460 with a 20 inch bar Also less stressing about the two cuts lining up 😉

Most flails will tackle scrub with heavy duty hammers rather than blades. Look for machines that are made with thick metal - some of the chinesey stuff is made from tinfoil. Dont be tempted to buy a wide flail for paths as this saps power. This type of cutting is hard work and you'll need all the power you can get. I have an ATV flail mower made by Chapman in the UK and its excellent, they also do PTO ones. I think a flail would be better than a rotary mower here. Felling work can leave the ground uneven and heavily rutted by the forwarders. A rotary mower won't like this. Just about worst that can happen to a flail is that the flails break or the clutch or belts give.

If you do put a 20 inch chain on a 50cc saw, make sure you keep the chain sharp and don't force the saw to cut, as this will stress and overheat the saw. Personally for occasional use, Id rather cut from both sides and get more power and cutting time from each sharpening. A 15 inch bar gives about 13 inches of usable bar, which will block up a 2 ft log from both sides.