D
dja981
Guest
Can anyone suggest a simple and accurate way to reamer out said bushes with crank still in cases?
DTI Dave
DTI Dave
Dave,
You will require a very solid and accurate guide jig for the reamer as well as for positioning of the rod.
A spiral-fluted fixed reamer is also to be preferred over an adjustable one.
The pin requires 0.02mm clearance and needs to be square to the rod in 2 planes... not easy to achieve accurately by hand. And the oil bores should be drilled before reaming.
I very strictly decline to do this.
If small end bushes are worn, there's so much other wear and tear in the crank to warrant a total rebuild.
piet
You will require a very solid and accurate guide jig for the reamer as well as for positioning of the rod.
A spiral-fluted fixed reamer is also to be preferred over an adjustable one.
The pin requires 0.02mm clearance and needs to be square to the rod in 2 planes... not easy to achieve accurately by hand. And the oil bores should be drilled before reaming.
I very strictly decline to do this.
If small end bushes are worn, there's so much other wear and tear in the crank to warrant a total rebuild.piet
motoddrob
Hero member
- Location
- S/W Australia
I wouldn't recommend it either having just done it. Guy reckoned he could do it, stuffed up 1 bush so had a replacement sent to him.
Picked up the motor, got it home to discover i pin would hang up on a lip I could feel with my finger. Ended up splitting the cases and sent the crank to non mechanic Red for a total rebuild with Carrillo rods. Red has a grounded 20mm rod that he uses to slide through all 3 little ends [180] to check the trueness. They were all out to buggery. That was $250 down the drain. Moral of the story, don't take short cuts.
Picked up the motor, got it home to discover i pin would hang up on a lip I could feel with my finger. Ended up splitting the cases and sent the crank to non mechanic Red for a total rebuild with Carrillo rods. Red has a grounded 20mm rod that he uses to slide through all 3 little ends [180] to check the trueness. They were all out to buggery. That was $250 down the drain. Moral of the story, don't take short cuts.
G
Grant
Guest
Cranks, heads and maybe even rebores should always be trusted to someone with a strong reputation in Laverdas.
Keith (Scotland), Piet (Germany), Red (Straya), Van Dijk (Holland), Wolfgang (Canada), Scott (US) and a few more besides.
Pick your closest favourite.
Keith (Scotland), Piet (Germany), Red (Straya), Van Dijk (Holland), Wolfgang (Canada), Scott (US) and a few more besides.
Pick your closest favourite.
D
dja981
Guest
sfcpiet said:Dave,
You will require a very solid and accurate guide jig for the reamer as well as for positioning of the rod.
A spiral-fluted fixed reamer is also to be preferred over an adjustable one.
The pin requires 0.02mm clearance and needs to be square to the rod in 2 planes... not easy to achieve accurately by hand. And the oil bores should be drilled before reaming.
I very strictly decline to do this.
piet
Thanks Piet
It's just the centre bush that needs replacing as it has moved blanking off the oil holes. Have adjustable and a parallel reamer though not spiral-fluted may as well have a go what could possibly go wrong?
Dave
CLEMTOG
Hero member
I am doing exactly this right now with a crank that was removed from a working but slightly rattly engine about five years ago, has been waiting for a refurb ever since.
This crank was previously rebuilt by a well known Essex based crank repairer who has a "Thunderingly" good reputation, before that,it was factory stock.He used "curled" small end bushes, which must be pushed into the rod eyes from the corect side, one side is prepared for this , the other is not.One of those bushes came loose, and was probably the cause of the rattle, easy enough to fix right?
Keith (Glasgow) has the crank where it has been waiting for a time slot for a couple of months (now under way) yes the small end bushes can be replaced and reamed to suit, but other damage was evident, aparently the oil slingers had not been cleaned by the previous repairer, one was damaged, (I was Unaware) all bearings should realy be changed, the spigot size for the outrigger needle bearing was undersize (bearing sleeve must have turned instead of the needles rolling) and at least one con rod is bent, so dont try to cut corners, get it out and get it to a specialist in Laverda, not just a crank specialist.
CLEM
This crank was previously rebuilt by a well known Essex based crank repairer who has a "Thunderingly" good reputation, before that,it was factory stock.He used "curled" small end bushes, which must be pushed into the rod eyes from the corect side, one side is prepared for this , the other is not.One of those bushes came loose, and was probably the cause of the rattle, easy enough to fix right?
Keith (Glasgow) has the crank where it has been waiting for a time slot for a couple of months (now under way) yes the small end bushes can be replaced and reamed to suit, but other damage was evident, aparently the oil slingers had not been cleaned by the previous repairer, one was damaged, (I was Unaware) all bearings should realy be changed, the spigot size for the outrigger needle bearing was undersize (bearing sleeve must have turned instead of the needles rolling) and at least one con rod is bent, so dont try to cut corners, get it out and get it to a specialist in Laverda, not just a crank specialist.
CLEM
MarnixSFC
Hero member
My Electronica had a small en bush give in a few years ago. While going flat out on the straight of Dijon racetrack the engine started to make nasty ticking sound. While completing the lap I noticed it would only tick above 6000 rpm. It was during the 2nd lap of the first session of the Coupes Moto Legende weekend.
I took the difficult (it was a 650 km drive to Dijon..) decision to not ride it any further, which turned out to be the right decision.
The bronze bush was the only damage on the crankshaft, fortunately.
Marnix
I took the difficult (it was a 650 km drive to Dijon..) decision to not ride it any further, which turned out to be the right decision.
The bronze bush was the only damage on the crankshaft, fortunately.
Marnix
