Hitchcocks Forum

Hello, con rod floating bush on my bullet sixty-5 is damaged. After we took motorcycle apart we saw that bonded seal in worm nut is damaged (it is waaaay smaller in size that it should be, and it falls out of worm nut easilly). Do you think that might be a reason con rod floating bush didn't get enough oil and therefore it got damaged?

Regards

The oil feed to the bottom end is designed to go via that route, so yes, that's almost certainly why it has a problem.

Although some on here say it's a waste of time it's certainly one good reason to drain the timing chest of oil every oil change. You get a chance to inspect the seal both visually and tangibly for wear and fit.

It would certainly be worth carefully checking the rocker assemblies as they're dependent on oil scavenged from the sump for lubrication. They may not have had as much oil as intended if some/most of it was just being pumped straight back into the timing chest via a bad quill seal.

Hi Guys--------that's a good point ric.........Just a reminder folks that on those old Iron Engines in the normal run of things ALL of the scavenged oil is passed up to the rockers and then down through the pushrod tunnels etc....unlike other Brit bikes of the day which would take a tapping from the scavange return pipe to the external oil tank...........Hello perorec}--- The bonded oil seal is exactly as it's name suggests ie}--- it's bonded into the worm nut.. so if it keeps falling out then it's Knac--- er, I mean "not right" and should be changed immediately....Don't forget that a Floating Bush big end is a plain journal type of bearing and as such requires a high oil pressure to get the oil across a large surface area..Typically 30 psi or more when cold............Conversely a roller bearing requires high Flow Rates of oil at lower pressures for heat removal.........With your engine dismantled you might consider fitting our hosts roller bearing kit and high flow oil pump conversion ??........It'll cut down the pressure on that bonded oil seal for one thing..................PS}--- I also run a Bullet '65 and have approached Paul Henshaw to do that on my machine....

Another thought on quill seal I would check timing side bearing for up and down play and end of timing shaft for runout easily done with cover off can do with 12v bulb with leads soldered to it one to batt other clamped to eng near shaft and bent close to ti ing shaft. If you can turn motor over and lamp goes on and off so ethings amiss with the crank.

Yup, always wise to check this sort of thing as it has been known for excess play in the shaft to result in a sheared quill.