Mower has two ignition coils - have swapped & checked each spark plug - plugs out & grounded, cranked engine - good spark on each.Can you better describe the vibration, as COVID has turned our crystal balls into snow globes. We are not standing next to you to see what you see. What color were the plugs you cleaned? I would start with new plugs, double check they are the right ones, and check whether both sides are firing. Might need to purchase two inline spark testers, so you can observe both plugs at the same time.
Check the for engine mounting bolts for tightness. I see lots of loose bolts from customers and will cause lots of vibration of engine.Two new plugs - no change
Removed the hydraulic & deck drive system, from engine crankshaft/PTO - no change. So none of the belt pulleys or electro clutch, are causing the vibration.
Engine starts & runs just fine - vibration (I would describe as medium to high intensity) remains fairly constant (little change with rpm) throughout rev range (ie from idle through to full throttle).
Tomorrow will remove cowling & double check flywheel, however if it was loose/shifted somehow, I would expect the ignition timing to be out and its not.
Anyone familiar with this engine model - please advise if anything can come adrift internally (eg counterweight/balance shaft/etc that may result in engine vibration??????
Yep. A customer will come in with problems and as soon as they start the mower, I know it is running on one cylinder. They just can’t tell.Most likely not cost effective rebuild unless you get really really lucky and nothing inside the engine is damaged Most likely 99.9% chance will require replacement engine.
And your response is typical of people that never realize that they are only running on one cylinder. People just don't know, and this is not anything that is against you. The typical customer issue is lack of power in cases where the grass in tall or they are driving up their hilly yards. On flat ground and normal grass cutting they don't notice.
The Pro/Commercial engines are just Intek twins with upgraded features which are below the quality of the Vanguard engines.Yeah! Thanks for that Lawn Royalty - The engine you recomend looks the goods. The extra 2 Hp will be helpful too.
My research to date, suggests that Australia is going through a bit of a B&S twin drought - the engine you specified is not available at the moment BUT Briggs & Stratton 25 Hp Vertical V-Twin Pro Series engine has been offered to me. From my perspective the Pro Series specifications/build is well below the 44T977-0009-G1 - what do you think?
It should bolt right up, just make sure the crankshaft diameter and length match your current engine or the specs of the 44T977-0009-G1Out of curiosity - Do you think that the 27 Hp 724cc (49T877) would fit without any chassis modifications???
Are you able to get Loncin engines? That may be an option. Their engines of that HP rating usually have a 1” crankshaft end. Of course, you will have to modify the wiring.Just found out that no 27Hp 1in x 3 5/32 in shaft motors imported in to Australia. Dont know why.
Good deal.Thanks for that MParr. I did a search - Yes Loncin are available in Australia. There is a 24 HP variant with 1" shaft. Very cheap. There is no dealership close to me. My concern would be parts back up. I think I will stick with the B & S that hopefully will arrive in Australia about mid June
Loncin is a Honda clone (Chonda). Loncin, LCT, Predator, Powermore, etc. are all Honda clone Chinese made engines, and have not seen any real issues with them on equipment that comes through my shop. Parts are available online. Dealers often order equipment with these engines to offer a lower cost to the customer. Since customers have often been conditioned to love low cost (Walmart), the popularity continues to grow.Thanks for that MParr. I did a search - Yes Loncin are available in Australia. There is a 24 HP variant with 1" shaft. Very cheap. There is no dealership close to me. My concern would be parts back up. I think I will stick with the B & S that hopefully will arrive in Australia about mid June
My first response to him about this was to cancel out cylinders so that would quickly be determined. LolI am a bit surprised that there has been no speculation, as to the cause of one piston no longer being attached to the crankshaft of this engine???????
I have an old Kawasaki water cooled engine that I inherited with the businessYep. A customer will come in with problems and as soon as they start the mower, I know it is running on one cylinder. They just can’t tell.
B & S Australia are pathetic and only interested in wholesaling to Bunnings & Mitre 10Just had a conversation with my local B & S agent;
He said that ever since CV19, supply of engines/parts (across several brand's) from the USA has been awful. Doesn't know why.
All of my single cylinder lawn mower engines only have one piston in the engine.I have an old Kawasaki water cooled engine that I inherited with the business
Owner always thought it was under powered for a big engine
There is only 1 piston in the engine and it only had one in there from new
Yes, the old horsepower wars and all the lies..B & S Australia are pathetic and only interested in wholesaling to Bunnings & Mitre 10
I no longer fit B &S engines unless specifically asked to do so
B & S Australia will tell you things are NLA when they are readily available either from the USA directly or from John Deere Australia because they are just too lazy to import them .
Genuine Gator blades being the prime example .
John Deere will supply B & S engines cheaper than B & S will and also they are cheaper for parts but of course you need to know the JD part number .
Better still is the JD engines have much better air filter covers that do not rust the fasteners like std B & S covers do .
Now you have to pull the engine out in any case so pull it out and slip the sump off and see what sort of damage there is inside .
You have nothing to loose but a couple of hours .
3 usual reasons for dropping a rod, in order , over heating , low oil , over reving
Small Engine Warehouse in Australia is affiliated wth Small Engine Warehouse USA who sell superceded engines cheaply
I buy a lot of Kohlers form them as my Australian aftermarket wholesalers only sell Kawasaki or Loncin .
Do not worry about the size of the engine, it makes almost no difference as they all spin at the same speed and the extra power means next to nothing unless you are mowing pasture .
I have fitted a lot of engines that are as much as 5 Hp lower than the original and all the customers ever say is the mower is quieter and uses less fuel.
And this includes 3 commercial customers who mow up to 6 hours a day.
It is TORQUE that does the work and Torque is a function of piston area , stoke & compression.
All B & S engines with the same capacity prefix 44 for instance have the same bore stroke & compression the only difference apart from the stickers is a restrictor gasket between the manifold & the head to reduce the maximum air flow on the lower power engines & some times the governor spring .
Unless you are north of the Qld border the grass should be slowing down by now
Here there is nothing growing here other than Tussock grass, clovers , fire weed & sticky night shade right now
Pull the engine apart and have a look at the sumpInteresting - This mower is second hand, is aesthetically in good order and since my customer has had it been serviced, minimal/nil chaff in the cylinder fins, does not use oil and was running just fine until dropping the con rod.
All are good considerations except the rattle gun.Delivery of new engine iminent!
I understand the new engine crankcase mounting holes will not be threaded.
There is some suggestion that the mounting bolts will cut their own thread.
Is using the existing bolts the best way to cut threads into the mounting holes???
Never done this before - Best technique By hand?? or Use a "rattle gun"??
OR
Should I tap/thread the holes to match the mounting bolts??
OR
Fit new HT bolts & lock nuts??? ie not bother with threading the crankcase holes.
Have you done a new engine install?All are good considerations except the rattle gun.
Briggs, Kohler, Honda, Tecumseh, MTD Branded engines. So I have done a few. The issue with the rattle gun especially with the self tapping bolts is they don't really cut threads as much as Pressure form them into the aluminum. So it is better to take them slow and turn each a little at a time to allow for some pressure relief. Rattle gun can force the bolts in ,which is some cases will cause them to break off. And self threading bolts don't come out without a fight.Have you done a new engine install?
Interesting!Briggs, Kohler, Honda, Tecumseh, MTD Branded engines. So I have done a few. The issue with the rattle gun especially with the self tapping bolts is they don't really cut threads as much as Pressure form them into the aluminum. So it is better to take them slow and turn each a little at a time to allow for some pressure relief. Rattle gun can force the bolts in ,which is some cases will cause them to break off. And self threading bolts don't come out without a fight.