Investigating that blue smoke

[roverfj1200]

Well I have had a bit of a problem with the 93 engine that I fitted to Effie. On start up it blows smoke (and I mean smoke) for well over 2 min and then slows. Then if you rest the bike 10 min and restart hay presto no smoke. I have no noticeable oil burn over the 400km I have ridden it, Investigation time. This morning I removed the headers and found oil around #2 exhaust outlet but none in the port. Popped the plugs and put my small camera in each cylinder and found what appears to be oil dripping in from the intake valves on to the pistons with oil laying in #2. So would appear that the valve stems are leaking( more than I have ever seen before) . I was concerned it was stuck rings but pretty sure now that it is seals. Hope its not a guide in #2. All cylinders are well within compression standard being 155 and 150 on #2. The cylinder being wet with oil could be why it is down 5 psi.

https://www.youtube.com/watch?v=RFv76wym1ms

https://www.youtube.com/watch?v=8FBx1X7jjLI

[Pat Conlon]

So what's the plan Richard? Pull the head and put in new seals? (Get the RPM Viton seals)
Lap the valves while you have the head off?

[roverfj1200]

So what's the plan Richard? Pull the head and put in new seals? (Get the RPM Viton seals)
Lap the valves while you have the head off?

Pat this engine is very low mileage so will change the seals with the head on. I only want to stop the smoke for now. Future plans will see some head work and bore and pistons done. Would rather get the body work done first.

[ribbert]

Well I have had a bit of a problem with the 93 engine that I fitted to Effie. On start up it blows smoke.......l]

Richard, if that engine has been sitting for a while, I'd put a few thousand km's on it before I touched it.
As you know, these things are good for at least a few hundred thousand km's untouched.
If the motor has been left sitting for a period of time it is more likely the seals have hardened up rather than worn out, a bit of use may return them to serviceable condition. It will cost nothing to give it a chance. If no good, do the seals then.
Even chronic overheating doesn't seek to worry them.

The time that old unused engines I bring back to life is measured in is decades, not years and I've seen plenty of this. Engines hate not being used but it's amazing what comes good with a bit of use.

My current FJ engine (for the last 100,000km) had been sitting outside under a tarp when I bought it, the wind had blown the tarp off and the inlet ports with closed valves were full of water and I had to chip the rust bubbles off the valve stems with a screwdriver. When I turned the motor over they stayed stuck open with rust.
The valves that were open had filled the cylinder with water. I had only intended using it for a few weeks and wasn't too fussed. Well, many years and miles later, it goes like the clappers, uses no oil and has great compression.

Noel

[racerrad8]

I am not convinced you don't have a piston ring problem. Looking at the photos, that is a large amount of oil pooled to be dripping from the valves. I say this because the valve stem seals are not immersed in oil and that amount would require them to be under the top level of the oil.

Secondly, the bike sitting on the side stand would cover #1 seals before #2 and you should be seeing the same issue with #1.

With that much oil, I'm thinking piston ring issue or broken ring lands on that piston.

Take some shots of the valves guides protruding into the ports from the in take and exhaust side and I can answer if you have a guide falling out of the head.

Randy - RPM

[roverfj1200]

I am not convinced you don't have a piston ring problem. Looking at the photos, that is a large amount of oil pooled to be dripping from the valves. I say this because the valve stem seals are not immersed in oil and that amount would require them to be under the top level of the oil.

Secondly, the bike sitting on the side stand would cover #1 seals before #2 and you should be seeing the same issue with #1.

With that much oil, I'm thinking piston ring issue or broken ring lands on that piston.

Take some shots of the valves guides protruding into the ports from the in take and exhaust side and I can answer if you have a guide falling out of the head.

Randy - RPM

G'day Randy

I don't park the bike on the side stand it is always on the centre stand.

I'm not sure it is always #2 that has the most oil in it. It was when I took these pix.

I have checked all the intakes to see the valve guides. They all look to be in the same depth with none moving as the valves open. I looked in the ports of the old engine and would say they are to about the same depth but have rounded ends not the pointy ones the newer engine has.

I removed the cam cover and all the valve buckets on the intake side are submersed in oil. I would think this oil could bleed down and ,if a seal was cracked or broken, would eventually make its way into the cylinder. What do you think. I'm not sure, is the oil around the buckets a drainage issue?

The pencil camera was not good in the ports but here are a few from #1 and #2

[roverfj1200]

Well I have had a bit of a problem with the 93 engine that I fitted to Effie. On start up it blows smoke.......l]

Richard, if that engine has been sitting for a while, I'd put a few thousand km's on it before I touched it.
As you know, these things are good for at least a few hundred thousand km's untouched.
If the motor has been left sitting for a period of time it is more likely the seals have hardened up rather than worn out, a bit of use may return them to serviceable condition. It will cost nothing to give it a chance. If no good, do the seals then.
Even chronic overheating doesn't seek to worry them.

The time that old unused engines I bring back to life is measured in is decades, not years and I've seen plenty of this. Engines hate not being used but it's amazing what comes good with a bit of use.

My current FJ engine (for the last 100,000km) had been sitting outside under a tarp when I bought it, the wind had blown the tarp off and the inlet ports with closed valves were full of water and I had to chip the rust bubbles off the valve stems with a screwdriver. When I turned the motor over they stayed stuck open with rust.
The valves that were open had filled the cylinder with water. I had only intended using it for a few weeks and wasn't too fussed. Well, many years and miles later, it goes like the clappers, uses no oil and has great compression.

Noel

Thanks Noel

There is no doubt I could jump on this bike and head off around Australia. I have covered 180,000 km on it myself. But that is not what this is about. I am refitting the bike and as things progress I want to make everything right. Many would be happy with it now but what is a project if your not working on it??

Cheers Mate

[racerrad8]

Are there any other cylinders showing the oil running out and dripping down the exhaust like you had in the previous photos like #2?

I would not be as worried about the intake guides as I would be the exhaust. We don't normally see intake guide issues on bike engines. The exhaust guides are usually the ones moving in the head due to heat. If the guide is loose in the head then the guide must be replaced with oversize guides.

Shoot some photos of the exhaust guides in the ports, that will be more telling if there is a guide issue.

Yes, the oil pools at the bucket and eventually will seep down to the return drain galley back to the crankcase. But, the guides are protruding up towards the buckets by about 15mm and then add the seal probably another 3-4 mm. The is no feasible way for the oil to pool that high unless the return galley was plugged. The galley is big and unless someone plugs it, there is nothing big enough up there to stop the oil flow.

The bottom of the spring base in the head is the floor of that return galley. I put a zip tie through the oil return galley.

So, I think you should be pulling the cylinders too since you are only on nut away after removing the head. That will confirm if there is a piston/ring issue.

Randy - RPM

[roverfj1200]

Thanks Randy those pix show how the oil flows well. #2 is the only header showing oil around the header. All the pistons have some oil on them but only#2 has pools of oil.

So this is the last bit of investigation till I dismantle the top end in a week or 2. Put the camera down the plug holes again and some as before oil pooled in #2 and oil showing on all other pistons. I removed the headers on #1 and #2 and run the camera down (see attached). There is definitely oil running down the valve stems in #2 and #1 looks OK. Guides seem to be in place. Valves in #2 have oil all over the head and stem.

So thats it for now will come back with the findings once the head is off.

[roverfj1200]

So here is a up date from this slow moving project

I removed the head and fitted new valve stem seals. Reinstalled and the problem is the same lots of smoke on startup. After a lot of talk with Oldktmdude pushing around ideas and going over things many times it was decided to fit the old head just to be sure the head that come with the motor wasn't cracked or something else. I fitted the head from the old motor and on startup things ran but there was a problem balancing carbs and alike. So I checked the valve clearances and there was a lot of tight ones so replacement shims were ordered. Today those shims were fitted and the engine restarted and tuned. Low and behold same thing smoke on startup and lots of it. once hot and left to stand for 10min the restart is clear. Crazy I know. Good thing is this motor has no starter chain rattle at all. So now looking back I think I know a bit more about this engine. The head seems to have been rebuilt recently as it is fitted with brass guides and the stem seals I removed were not factory. Seems the old owner was trying to fix this smoke problem and gave up before finding it. I have everything here to replace the rings if or when I pull the barrels but for now I might just ride it some more and see if it clears it self. There are no scores in the cylinders and I don't think riding it more will hurt.

[Troyskie]

We all know FJ's almost self tune when given some good regular riding and a little fang on each ride. It seems to solve so many FJ running issues (and is great therapy for the rider).

I have some oil rings on one of my effies that have no tension left. It uses a heap of oil, but no smoke on start, just the usual smoke on decel (guides are original). Strangely it doesn't seem to smell rich to those behind me. Just another FJ foible I suppose. It won't be a problem much longer as she is in bits right now for a frame up rebuild. Just received a heap of pressies from RPM  .

It could be a rings issue, but I've not seen that much oil leaking in, however I've seen plenty of smokey motors that seem to just go and go.

Could the valve keepers be the culprit?

[Troyskie]

Scratch the keepers, you changed the head 

[ribbert]

So here is a up date from this slow moving project....

What set up do you have for crankcase ventilation and is it in good nick, as in not kinked or blocked.

[racerrad8]

There are no scores in the cylinders and I don't think riding it more will hurt.

Be careful...

If the piston ring land is broken, then there is a possibility it can break apart, gouge the cylinder or create additional piston friction. If any of these start happening and it overloads the rod bearing it could knock it out. That would result in a damaged crankshaft, connecting rod issues or worst case scenario the rod hanging out of the block.

You had the head off twice now...

If you would have removed the single 12mm nut at the front of the cylinder and lifted the barrels you would know the cause.

Buddy, tear that thing down, especially if essentially the head has now been off three time with the previous owner already having the original head rebuilt.

I bet you can have it apart in less than 30 minutes.

Randy - RPM

[roverfj1200]

So here is a up date from this slow moving project....

What set up do you have for crankcase ventilation and is it in good nick, as in not kinked or blocked.

Have pods on the bike Noel and the crank vent is the standard hose and filter.