Two questions

[Chaz]

Hi folks hope the lockdown isn't stopping you get some vital exercise on the roundabouts. I wonder if anyone can offer suggestions:

I recently changed the oil (after 4000km) because I was planning to be overseas for a while and The oil had been in for a bit. I used Gulf Western SynX 3000 (recommended here). I believe it had silkolene at the last service. I was out for a short run this afternoon and noticed a sound like rattling tappets. First time I've noticed it (bike only has done 34000 km) . Another check on the forum seems the consensus is nothing to worry about, but while I was poking around trying to find the source, I noticed a leak around the throttle intake pipe assembly .

I recently sprayed S100 on the engine and it revealed  a very small leak around the seam - very minor but I can see a sign of "bubbling".

Just curious to hear if anyone has experience with either of these issues?

[Andre]

S100 has many products, which one did you spray on there? Maybe the bubbles are just an effect of the S100 product's reaction with the crud collected there.

Bubbles are not what I would expect seeing in a vacuum leak as the liquid gets drawn in, not out.

To test if you have a leak use something that is commonly used for this (carb cleaner). While the engine is running, spray at the suspected leak area. If there is a leak you will notice a change in RPMs.

If you have a leak at the seam between the intake pipe and the engine, the cause is likely with the O-ring that sits there.

The result of a leak is a lean AFR. That makes for higher temps that may damage valves.

[Chaz]

Thanks Andre

I sprayed on the engine brightened. You are correct, it wasn't so much a bubbling, more like small waves as the residual fluid moved. I will try some carb cleaner ( when I can get some after the Easter weekend) and test your theory. Perhaps a good idea just to replace the intake pipe.