Forum

[Dennis C]

These type of engines almost always smoke after a rebore piston, stop worrying, take it out and ride it, if it is still doing it after 500 miles or so then start looking for the cause, but I bet you won't need to.

[Beezabryan]

First I would replace the rings in the correct places, as said by Presto.

Then I would ride it for a few hundred miles/ kilometers and see if it is clearing. Then then ride it a few more hundreds of Kms.

[Gwilly]

I think you've got it cracked Jyrkik, draining the chest and leaving overnight proves it can only be the timing seal as you've changed the worm neoprene..

Led you a merry dance didn't it, still after 16 years it hasn't done bad..

Make sure you fit with the spring on the outside, facing the timing chest..

Also a tip, use a dowty seal on the front sump plug, it seals well but also ensures the return hole is not blocked by the thread which can happen if the plug is wanged up tight and the drilling tolerance is shall we say "Indian".

[jyrkik]

Hi,

Did you read the thread from the beginning? I get 0.3-0.4 liter of oil into the sump during a night. That indeed does smoke like a destroyer and definitely is not ok. Normal amount of oil in the sump would be maybe tenth of this. I have rebored the bike Once earlier during the ownership and have never experinced anything like this.

Jyrki

[Dennis C]

Well I read the whole thread, no wet dumping before rebore, "tin almost empty", "next to no oil in timing case", " no oil dripping overnight", " .3 -.4 l in the bin", I'm now confused.

[jyrkik]

Well,

I can see my english doesn't serve the purpose too well and the storyline might be hard to follow. Anyway, the bottom line really is that the smoking started after the rebore. But on the other hand it's hard for me to understand why this happens now as after the earlier rebore some 5 years ago there was no effect like this. Maybe it is because of the type of the piston.. Previously I used the Hitchcocks 8.5:1 piston (the one with crowned head). That piston has quite different ring arrangement than the cheaper piston I am now using (Hitchcocks american 9:1). Does anone have any comparable experince with thess different types of pistons?

Jyrki

[jyrkik]

Hi,

I replaced the crank timing side seal, but unfortunately it didn't cure the issue. The engine still smokes after start for few minutes so badly that it just cannot be started in the neighborhood. The whole block would be covered with smoke...
Hence, before start every morning (or which ever few hours standby) I need to drain the sump.

Because I have to my understanding fixed or checked all proposed ideas attempting to fix the isse, apparently I just need to run the bike for few hundred kilometers (as proposed by many) and see if the issue cures itself. Or just dump the whole bike - which has turned from a nice vehicle into a piece of metal crap.

Thank for all advice anyway.

Jyrki

[Dennis C]

Jyrkik, that is the best thing you can do, every rebore/hone and ring set is different and smoking is common due to the rings passing the oil, once the rings and bore bed in the smoke will stop.

[Bullet Whisperer]

Hi Jyrki,
This bike has been rebuilt with the Hitchcocks American '9:1' piston and the barrel has been shortened. The video shows the very first start up after reassembling the top end and there are other videos of varying degrees of poor quality featuring this machine being ridden and checked afterwards, which you are welcome to find and watch if you like. There has been no smoke, leaks or rattles from this machine and it has now done over 60 miles with just a head retorque and valve / pushrod adjustment since the rebuild. I have the chrome like piston ring at the top, the ring with the word 'Top' facing upwards in the middle groove and the oil ring, obviously at the bottom of the piston ring grooves. Hope you sort it, one last thought is your base and / or head gaskets may be leaking internally - it can be quite common and the cause of all sorts of oil and breathing related issues. Regards, Paul. https://www.youtube.com/watch?v=iqPpezucjyU

[Cleggy]

On a new Hitchcock's bullet piston I saw the other day (and on all my new Interceptor pistons), all three piston rings are marked "top". Never heard of the middle ring only being marked "top".