Running in

[Wilf2019]

Hi all,
I've recently got my rebuilt A65 Thunderbolt registered and on the road.

I currently have running in engine oil in it. Is that the best thing to do, or should I just use the standard grade oil?
It does have new pistons, rings, valves and new guides etc.

What is the best procedure for running in?

I've covered about 30 miles on it so far with only a couple of issues.

The issues I have so far are;

The head gasket seems to be weeping oil very slightly in the centre at the back.
Is it best to try re torquing this? I fitted a new copped head gasket but didn't anneal it.

The forks top out occasionally over a bump.
I have fully rebuilt the forks, with new stantions, bushes and seals.
Could this be a oil issue or the plastic sleeves fitted the wrong way around?

The final issue is that the primary case plug weeps oil slightly.
I have blanked off the breather over the chain, but the casing plug has the baffle plate and breather hole in it.
I'm not sure if it is leaking out of the primary plug threads or the small hole in the plug.

Any help on the above would be much appreciated.

Thanks in advance.

[DAVE BRADY]

Hi Wilf,

I have used running in oil and if running in is done properly then your engine will last along time.
The usual instructions are not to rev the engine too much or to allow it to labour at low revs.
I also believe in not sticking to constant revs but rather use a range of revs but again not labouring or revving.  I changed the running in oil after 50 miles then half and half with 20/50 for another 50 miles and then used what running in oil I had left topped up with a 20/50 for 100 miles.  Then 20/50 up to 500 miles, change at 1000 miles whilst increasing the engine speed and using the torque from lower revs but again not labouring the engine.  Changed the oil again at 2000 miles and considered the engine run in.

I blocked off the chain drip feed and have a slight weep from the primary caps.  I decided to not use the level screw but put in the recommended amount of oil, 140 ml, and this made a big difference.  Using the level screw could result in too much oil in the primary case.

Your new head gasket may have already ben annealed.  Ask the supplier if they know.
It is strongly advised to re-torque the head after a few hundred miles so you will see if the bolts were all tightened down properly in the first place.  You may find that just re-torquing will solve the issue but just check the rocker feed just in case this is weeping but showing as if it is coming from the head gasket.

Try some thicker oil in the forks before stripping them down.

Dave.

[Wilf2019]

Hi Dave,

Thanks for your reply and advice.

I have not had much time to put many miles on the engine as yet.

When the bike was stood for several months it wet sumped - as I understand this is normal.
Is it OK to just drain the oil from the sump and put back in the oil tank? Or should it really be filtered or replaced?

I will continue with the running in oil for a few more miles and change to the 20/50 as you suggest.

I did fill the primary to the level screw, and this was more than the book suggested, but I wasn't sure which to go by. Therefore, it could be coming out of the primary plug due to being over filled. I will just try putting the required amount in instead and see how it goes.

I will firstly try to re torque the head bolts and see how that goes. It is a very small weep, but I'm sure it will get worse over time. If i do end up changing the gasket I will anneal it just to be safe.

Also I will try changing the fork oil. What oil do you suggest?

Many Thanks,

Wilf.

[DAVE BRADY]

Hi Wilf,

Normally it could be ok to put the oil back in the tank if it was very clean but as you are running the engine in it is likely that there will be particles in it from the running in process so unless you have an after market spin on cartridge type filter I would suggest not putting the oil from the sump back in the tank.  If you have an after market sump plate with magnetic plug the magnet will catch quite a lot of material but it is not worth taking a chance for the sake of some oil.

Dave. 

[DAVE BRADY]

Hi,

Forgot to mention fork oil.  I use a straight 30 oil.  Usually smaller quantities are available in lawn mower shops.

Dave.

[Wilf2019]

Thanks Dave,

Your replies and advice are much appreciated as always.

Regards,
Wilf.