OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Question On Scott Bonnar Cylinder Mowers Rover 45 Cutter Clutch Help

Howdy Folks,

After much fence sitting and information gathering on this forum, I have bitten the bullet and bought my first cylinder mower (Many thanks for all the good advice and experiences).

I ended up picking up a Rover 45 which was is good condition but unfortunately seem to have had some issues with the cutter clutch at some point in its 11yr life. (just a baby I know!).I was suspect of this prior to purchase and, as the price was right decided to get it anyway.

The problem is the cutter clutch lever does nothing -i.e. the cutter is always engaged.

It would appear that this whole assembly needs overhauling as the clutch housings are cracked (where the thread is tapped into the main body and the outer body bolt holes have been elongated) and I was curious if parts are still availible for this model??

Are there any tips/tricks in setting up the alignment of the clutch on the crankshaft/clutch fork/engine shaft???

It is a Rover 45 Model: 45058

Briggs & Stratton Model: 91202
Type: 1371 E1
Code: 0106223A


Will post some pic's of this in the next couple of days!
Regards,

Andy

Hi Andy, and a warm welcome to the forum. It's always great to welcome another cylinder mower owner on board.
Essentially, your machine is identical (with a few minor changes) to the Scott Bonnar Model 45 thus all parts are still available. Your engine was manufactured on the 22nd June 2001.

My advice is to:
1. Remove the plastic safety cover that covers the clutch assembly if you have not done so.
Remove the 3 screws that hold the clutch housings together.

2. Remove the 4 bolts that attach the engine to the chassis and slide the engine carefully and rest on a suitable surface the same height as the chassis rails (a milk crate for example)....this is so it will not put pressure on the throttle cable still attached.

3. Remove the clutch half attached to the engine by releasing the 'captive cotter pin' by loosening the nut till it is level with the top of the thread and tap it gently down to release it from the engine shaft and slide the clutch half off. Remove the captive cotter and stow safely for replacement in the new clutch half. Discard the cracked one.

4. Slide the thrust bearing, spring and clutch cone and other clutch half off the clutch shaft and remove and safely stow the half-moon (Woodruf) key.

5. Carry out a thorough inspection of the bearing, spring and cone for damage and replace if necessary.

6. Purchase both new clutch halves (not forgetting to measure the engine shaft diameter as there is 2 sizes for the engine side housing) plus a new cork clutch lining for the outer clutch half and glue in place.

7. Replacement is the reverse of the above steps.

When this has been completed we will step you through the adjustment procedure.
Once again Andy,

Hi Deejay and thanks for the advice.

I have removed the clutch and main shaft from the crank shaft. I did it slightly different; by removing the sprocket from the main shaft and sliding the whole assembly towards the engine. Same result - will this make re-assembly harder?




Looks like you were bang on with the parts required, will need only both clutch halves and the cork lining. Also will need the plastic thrust pad for the fork. You can see how the castings are cracked presumably from the bolts becoming loose.



I am a bit confused about the "captive cotter pin" to which you refer. The housing was attached to the crankshaft by two set screws???




I think I will remove the reel and bed knife and get them both sharpened as the previous owner, who has had it from new, said he has never shapened them.

PS: I found your recent videos describing this proceedure very informative. Presumably the process is very similar for the Rover 45?

Again, many thanks for the valuable advice.

Cheers Andy

I recon your clutch problem is due to the worn thrust pad not the housing or the clutch itself.
Your clutch to me still looks servicable maybe using nyloc nuts & bolts instead of screws if the thread is damaged as the clutch housing just clamps together.
The cotter pin must be used on older scott bonners the spare parts clutch housing seems to use set screws aswell, your engine doesm't have the ground flat on the output shaft for a cotter pin, it has a keyway
I would try the bolts and purchase a thrust pad only, your cork clutch lining looks fine.

Re cotter pin: Actually now come to think about it, my SB45 doen't have a ground flat on the output shaft just a keyway like yours.
It is not a cotter pin like on pushbike cranks (if you can remember them) but rather a half threaded 3/8" pin with a semi circular cutout that clamps the output shaft when you tighten the nut up, a better way of holding the clutch as it won't leave dimples like set screws will.

Hi Andy, yes mate, I forgot that the Rover housing differs from the older Scotty's with the captive cotter pin....I also appreciate what AndyOz has replied...but using bolts to secure the clutch halves is not the answer, as it throws out the balance and vibration is the enemy of these machines....having a nut or bolt drop out due to vibration and then mowing over it can spell disaster for the cylinder reel. Many$$$ to replace!

There are 2 ways to get the clutch off, the easy way or the hard way....you have chosen the hard way
My advice....replace the cutter shaft, sprocket and chain and clutch fork and handle....remove the engine and replce the new parts in the reverse of removal, as per my original post. This will make final adjustments easier.

The parts can be purchased from the OutdoorKing online store...located in "Site Links" navigation panel on the left.
Select Scott Bonnar frame parts.

Just remember to measure the diameter of the engine output shaft when ordering the housing....If the Rover housing with the set screws is not listed...just send a PM to Bruce...he will source one for you.

Deejay, sorry but I gotta to disagree about the bolts.
How can 3 bolts spaced 120 degrees cause inballance? it will do so as much as the 3 screws that are 120 degrees apart, the things that would cause imballance in the clutch assembly depending on the age of the machine are the 2 set screws or engine output shaft clamp pin.
As for nuts and bolts dropping off, I would whole heartedly trust a bolt with a nyloc nut a whole lot more than the original screw, spring washer and nut. Hmmm wonder how BlackMilk's elongated holes in his clutch hosing came from?
I'm all for original but some things are better/ safer modified than OEM specs.

I was just offering a alternative to BlackMilk to dropping ~$150 for a new clutch housing.
Cheers Andy

The clucth housing is not tapped, there is a nut & spring washer attached to each screw.

Hi andyoz,

I initally thought that the outer clutch housing had a thread tapped in to it, but now agree with you that the two halves are "through bolted" after downloading the exploded parts drawings.

There did appear to be thread tapped into the outer housing, but this may have been just been impressions created when the bolts were loose. I agree that new bolts and nylocs would solve the problem, but the fastener holes in the two housings were the shape of footballs and for the sake of $100 ordered the parts and parted with the cash!!

Lesson 1. For new owners like me. Keep nuts and bolt on tight and oil regularly


I do appreciate everyones advice greatly.

As an aside, whilst waiting for the parts, got my cutter reel sand blasted, powdercoated and shapened along with my bedknife and was wondering? The cutter shaft bearing sheilds are concave; which side goes towards the bearing, any ideas? Should have paid more attention when breaking it all down.

Warm Regards,

Andy

Hi Andy, the dome side goes towards the bearing.
Don't forget we have a video in this forum topic on the replacement and adjustments required....Click HERE
Great to see you got your reel and bedknife sharpened.
Please post some pics of your powder coated cylinder reel

Hi Andy Oz, I agree with what you have said about the bolts; you could use them successfully with nyloc nuts....but wherever possible here we encourage originality if a member is restoring a machine. Plus the fact that not everybody would trot down to Bunnings and buy 3 bolts the correct size and length and nylocs to suit....many would just dig around in the shed and see what they come up with.....and then we could have a balance problem.....plus where a member mentions cracking in alloy....we would normally recommend replacement.
Andy, sometimes it's hard to give advice here...especially when you can't physically see what your looking at....and pics don't always tell the whole story....but we do support best workshop practice.
Thanks mate for your comment.

A couple of pics of the cutter real after sandblasting and powdercoating Prior to sharpening. Sole plate and bed-knife just a light blast and a quik spray with paint.





Cheers,


Andy

Looks very nice mate!

Thanks Wazzbat,

Looks a lot better than it did after I first bought it 3 weeks ago!

I rang the local golf greenkeeper, after it being suggested on this forum, to find out who the local sharpener is on the gold coast. They put me in touch with this guy in Nerang who's sole bussiness is sharpening & repairing cylinder mowers.

Met with him today, Lovely bloke. He actually showed me how to adjust the reel to bed knife clearance and how it should cut paper. Awesome!!! It was on a 16 blade Jacobsen number with relief ground bed knife and reel. I had no idea how sharp they are!!!

Pick it all up at the end of the week!

Andy