Blown head gasket?

[heavymetalmullet]

One of these days I'll have a post on here that says how much fun I'm having riding my FZR... however I have a horrible feeling that my head gasket has blown.

To give some background I bought a FZR400 1WG 3EN1 off eBay just before x mas that hadn't been started for 18 months. So far I have replaced the carbs with a clean set with intact diaphragms, overhauled the old brakes with braided brake lines and new pads and at the weekend I flushed the radiator and replaced with new coolant. Once this was done I left the bike idling for a few minutes, engine and carbs sounded fine when twisting the throttle. I did notice some bubbles in the coolant reservoir bottle. A puddle of clear water starting to appear right under the bike where the EXUP valve is and also the over flow(?) tube that comes out of the coolant reservoir was leaking coolant out the end of it. I thought I'd give it a quick go up the street and back and noticed the acceleration was very stuttering and a few more yards up the road the bike pretty much died as I changed down the gears. Had to push it back home as it now no longer starts and when I did manage to get it going once back in my garage with some cold start it sounds like it's not firing on all cylinders and won't idle!

I can't see any milky crud in the oil observeration window or under the filler cap and I also need to check the spark plugs (which apparently were newly replaced by the previous owner)

What do you guys think the next best course of action is? I don't have a compression tester to check the Sparks but there is a mobile mechanic based about half an hour away who I could possibly get to come and diagnose the problems, do you guys think that's worth doing?

Really wanna get this bike up and running now!!

[Evilchicken0]

If the head gasket goes you'll have white smoke (steam) out of the exhaust, the oil turns a bit grey.
Renew the plugs, and clean the carbs main / slow running and idle jets.
Make sure the exup cycles from closed to open and back when the ignition is turned on.
Look at the carb / engine stubs and make sure the carbs are on them properly, and the stubs themselves aren't letting air in past the carbs.

Did you check the valves / cam tolerances ?

[heavymetalmullet]

If the head gasket goes you'll have white smoke (steam) out of the exhaust, the oil turns a bit grey.
Renew the plugs, and clean the carbs main / slow running and idle jets.
Make sure the exup cycles from closed to open and back when the ignition is turned on.
Look at the carb / engine stubs and make sure the carbs are on them properly, and the stubs themselves aren't letting air in past the carbs.

Did you check the valves / cam tolerances ?

Hello mate, before I put the carbs in the bike I opened them up and gave them a good clean and also bought brand new rubber carb joints and made sure they were sat right on the heads (didn't look like the original owner had done that right). The EXUP cables sweep through the motions when I switch ignition on.
I'll replace the spark plugs and have a good look at the oil as soon as I can.
Is it worth draining the coolant again and checking that for any oil that's got into it?
Haven't checked valves/cam tolerances, never attempted anything like that before. Is it easy enough to do or worth paying a mechanic to take a look once I have removed the tank, carbs and air box again?

[Evilchicken0]

You can check the coolant by taking the top off the radiator, if there's brown sludge / foam in there that's the oil. Same if you take the oil filler cap off.
When you cleaned the carbs did you take the jets out and clean them, or just get the crap out of the bowls ? Have you changed the fuel filter (it's cheap)

It's not "easy" to do the valves, ask around if there's somebody to help you. I would use a FZR600 manual to guide you through it. Do the other stuff first, if that doesn't work then we'll get into this

[heavymetalmullet]

You can check the coolant by taking the top off the radiator, if there's brown sludge / foam in there that's the oil. Same if you take the oil filler cap off.
When you cleaned the carbs did you take the jets out and clean them, or just get the crap out of the bowls ? Have you changed the fuel filter (it's cheap)

It's not "easy" to do the valves, ask around if there's somebody to help you. I would use a FZR600 manual to guide you through it. Do the other stuff first, if that doesn't work then we'll get into this

Took the rad cap off and the coolant definitely appeared darker to me than what I put in so I emptied it into a bucket and i'm pretty sure it's darker than the bright pink it was when I put it in on Saturday after flushing clean water through the system. I've attached a pic!

As for the carbs I took each jet out and gave them a good spray with carb cleaner, they actually looked very clean to start with but I did it regardless. I also changed the fuel filter while I had the tank and carbs off as it didn't look like it had ever been done. As for changing the sparks is it worth going for iridium ones or will standard ones be good enough for the job?

[Evilchicken0]

Hmm it shouldn't change colour that quick, if at all. It might be some of the old fluid already in the system mixed with the new though.
Just use the standard CR8E NGK plugs

[cbr400rrn]

Hmm it shouldn't change colour that quick, if at all. It might be some of the old fluid already in the system mixed with the new though.
Just use the standard CR8E NGK plugs

+1
Mine originally had a green colour antifreeze in, changed it and the new blue antifreeze turned from that colour to one with a tinge of green to it in a few weeks

[Evilchicken0]

Is blue ok for aluminium ?

[cbr400rrn]

silkolene last time and Honda coolant this time and they were/are both blue from memory (but age is killing it)

[Evilchicken0]

Ah - I use Halfords concentrate, which is pink for alloy engines