My bike (01 F4i) has always run hot but recently since last month or so had a problem where it was leaking coolant out of hose ends, reservoir cap and overflow hose. Enough to leave some pale green streaks on the sides and, when I parked bike hot, it would drip couple drops until cool.

I thought the coolant hoses are probably old (as it was leaking out the fiber holes as well) and maybe these leaks causing the coolant to boil over too soon. Even if I was wrong, the hoses definitely needed replacing anyway. What do you guys think caused the leaks btw??

Anyway I ordered brand new oem hoses as well as new radiator cap, which I installed this weekend, burped the new coolant (tapped with hammer as well as ran bike w/ rad cap off until ~192 F (believe the thermostat should be open by that time) and took for a short test ride.

Good news is I don't see any leaks (yet, need to take a longer ride)
BUT while looking for leaks I found THIS:



Can you see it? That was the best picture I could get, it was hard to take. But basically that is right under the headgasket area, seen from the left side of the bike next to the stator. Dark golden caramel brown and pretty flat, it looks like it came seeping from that seam right there... doesnt look like coolant at all though.
Whatever it is, seems to have been there for awhile as it's pretty dry/baked on (does not wipe off)

This, combined with my last oil analysis report from Blackstone Labs, got me worrying. Says they found sodium in the oil, possible sign of coolant. (Previous analysis reported normal wear) It seems very possible to me that IF high pressures caused coolant to leak out the outside, it could have done the same on the inside...



Brief history of the bike:
Engine was rebuilt at 41k mi, with new rings, bearings, ballhoned, valves cut etc.
Crankshaft and associated conrods/bearings replaced at 42k.
New water pump at 43k.
Noticed coolant leaks around 44k. Prior to engine rebuild I don't remember seeing coolant leaks anywhere (even in the hoses buried deep inside as I dropped engine myself) - if there were leaks it must have been very minor.
New hoses and rad cap installed around 45k.

Some pics of the old coolant leak (you can see some coolant seeping out of fiber as well as the gap... there was a bit more but I wiped it off before remembering to take pic, oops):





Also, noticed some wear on the waterpump when I took it off to install the new hoses. Is this normal wear for a water pump with only 2k mi on it?





Any thoughts guys??? what that golden brown mark is, what caused coolant leaks, anything to watch for or ideas on next steps.

Thanks in advance.

 

Hmmm, that's a tough one. Since you're saying the engine was rebuilt, that brown stuff could be engine shellac from when they put it all back together.

I've had hoses leak before from the ends. I actually put a second hose clamp on one and it stopped leaking.

Testing for head gasket leaks is kind of simple. Pull the radiator cap of, let the bike warm up and see if you see any bubbles coming up through the radiator. That's a pretty sure way to tell there's a breach of exhaust gases getting into the coolant.

^^^ This would cause the coolant overflow to become too full eventually, and leak. Also, the bike would run really hot - especially at a standstill.

Who rebuilt the engine?

 

I actually tried the second hose clamp trick and it did help some but some of the hoses inside (under the throttle bodies) were leaking too so I figure for the effort to put clamps there might as well get new hoses, $$$ but oh well. I think it would definitely have helped for smaller leaks.

For checking bubbles at the radiator cap, how long should I let the bike run? When I was running the bike with the rad cap off to burp the coolant, above 193F ish the coolant level started rising and I shut it off so it wouldn't spill out.
So if I see any bubbles then its headgasket for sure?

I did not rebuild the engine myself, it was done by a shop here, Moto Tecnica.

The symptoms you describe (overflow hose leaking and getting hot at stoplights) are spot on, tho as i understand it f4i's do tend to run hot so I don't know. I went on a slightly longer ride today (about 120 mi) and so far there are no leaks that I can see, no leaks from overflow, hoses, etc. Really hoping it's not the headgasket.

Thanks for the reply.

 

If the bike has run well since the rebuild (which it sounds like it has) I'd swing back by the shop that did the rebuild and ask them to take a look. Obviously not warranty at this point but they may have an idea.