F115 oil leak

[grpaxto67]

Hi Everyone,

i have searched and found some great information relating to oil pump / crankshaft seal leaking on the F115 s. I have an 09 F115 (255 hrs) that is leaking around the plastic side cowling and the front drain holes on the front of the engine when tilted. I can’t see any leaks from the engine block, flywheel, camshafts or sender and based on my local Yamaha dealer recommendation dropped the the lower unit to see if oil was evident as they believe if the oil pump is leaking it wil be present there. Inside was as dry as a bone but I still think the oil pump is leaking from the seal.

Is it possible to have an oil leak from the pump and not have it leak internally down the leg? Yammie dealer says no if the oil pump was the issue it would be evident there. They have de-greased and changed filter in case of pin hole leak but so far after three days of troubleshooting can not identify leak. Tank testing has not been able to raise a leak.

cheers

greg

[pstephens46]

You could try degreasing the pan with with a spray similar to GUNK. And then using a dye mixed in the oil like this:https://www.nationaltoolwarehouse.co...SABEgLsRvD_BwE You would need a ultraviolet bulb in your work light.

Tilt the engine back up with cowl removed to try to find where it is running from. I wouldn't think a leaking pump seal would dump oil in the pan/cowl area.

[rodbolt17]

if it is leaking in the cowl it is not a pump. the pump mounts on the powerhead adapter somewhat below the cowl.
like it was said,caarefully clean the engine.
you can get the dye at napa.. use a black light.
to speed up the testing block off the crankcase vents.

[johnbruce]

when tilted up and turned to the right
oil leaks out around the dipstick rubber.

[panasonic]

Rubber seal gone bad? Turn her the other way then...problem fixed.

[TownsendsFJR1300]

Not knowing your model #, it seems the dip stick has the seals attached to it, part #27

http://www.boats.net/parts/search/Ya...PAN/parts.html

[grpaxto67]

Okay, so I decided to spend some money on my F115, did the oil pump, new fuel pump, cleaned VST and change filer plus injectors serviced and new timing belt. Running like a dream BUT I still have a slight leak on the RHS near the valve cover. I can see the oil trail on the plastic shroud when I removed it. It had a new rocker cover gasket installed when timing belt was replaced and I have inspected with a mirror and retorqued the bolts. It seems to pool under the bottom spark plug lead holder and drip out from there.

Has as there been any issues with pourous rocker covers leaking when hot?

[grpaxto67]

I have finally found a leak on the lower threaded boss for the spark plug lead cover where the lead holder goes in. I thought the valve cover would come off without removing the cam drive gears but I don’t think it will. Could anyone confirm if it does or not? Has anyone come across a leak from here? Hopefully I can get it welded/brazed up or use some type of sealant? Any thoughts?

[rodbolt17]

looks like someone whacked it with an impact driver. that threaded hole is originally a blind hole.
yes the cam cover can be removed without messing with the cams or sprockets. yes it can be welded.

[TownsendsFJR1300]

https://www.boats.net/catalog/yamaha...r-crankcase-26

[grpaxto67]

Managed to get a second hand cover from wreckers very cheap and put it in today. I must not be holding my tongue the right because there was no way in hell I could get that rocker cover out without loosening the timing belt and removing the camshaft gears. That top area doesn't have enough clearance. Anyway - simple job

Looks like you are spot on rodbolt17 as I can see the crack easily from inside where that threaded boss is and judging by the condition of the phillips head screws that go in the bottom positions I reckon the previous owner tried to get them out with a hammer and impact driver and gave it a bit too much juice.

[grpaxto67]

Here’s the offending crack from inside. Poured out when warm.