October 2012 -
First incident of spark plug fowling; this after dragging 4th gear to about 7-8000rpm. All 4 spark plugs burnt out. Mechanics thought it was the wrong size spark plugs that were put in during my first service after getting the bike and swapped them out for new ones

November 2012 –
Bike overheats to red line while travelling in heavy traffic. Fan did not turn on. Checked coolant reservoir and found it completely empty. Topped it up and the moment the bike started it started puking coolant onto the street. Brought it down to a mechanic and he said my thermostat was faulty but wasn’t important to replace. He instead installed a fan switch to turn on once the bike starts running.

December 2012 –
Bike idled and suddenly stopped running in the middle of the road. Pushed it to the side and tried to start it but it couldn’t start at all. After cranked the starter a few times a loud snap sound and steam was seen rising from the fairings.
Pushed the bike to a nearby mechanic and they found once again all spark plugs were fowled. They opened up my carburetor and took a closer look and found that it had been modified to suit the aftermarket exhaust system installed. Thought it was jetting too much fuel in so they replaced parts to revert it to stock.

January 2012 –
While riding at about 8000rpm (again), the engine started to choke and feel sluggish. When I parked it I could here a squirting sound coming from either the engine or the radiator. Regular intervals. Sounded like someone squeezing a sponge really loud. Brought it to a mechanic again and they found 3 spark plugs had been fowled. Found no issue with the carburetor.

February 2012 –
Decided to fix the thermostat as I had time. Asked a mechanic from a different workshop what was wrong with my bike as it kept fowling plugs. He revved it hard and billows of white smoke came out. Told me it was either a piston ring damaged of head gasket and had to run a compression test to find out which it was.
Just found out that head gasket is ruptured, 2 piston rings damaged and 1 cylinder experiencing 70% loss in compression.

WHAT SHOULD I DO?!

Hi there, the post above is actually my bike. Thanks niteblade for helping me post it up.

Also, i noticed the engine chokes up whenever i drag my gears past 7000-8000rpm

Have the last mechanic fix all of those things, and give it a full service (inc. carbs), if you've paid the other mechanics ask for your money back as they clearly don't know what they're talking about.

Unless you're an expert yourself you won't want to fix these as it means splitting the crankcases.

Best of luck :)

Simple answer bud, get a head gasket, all new piston rings and fit them :) lol

At least when the engine is apart you can check to see if anything else is amiss or doesn't look right.
Its not as hard a job as you may think, take a while to do it but pretty straight forward.

Also give your carbs a rebuild while your at it and make sure all float heights are set right and the needle's are opening/closing properly, and that your mixture screws are set correct aswell as your carbs being balanced properly.

If your not confident enough to do it yourself, Graeme france is your man to talk to about having it rebuilt
I would offer to sort it out for you myself but i have a few projects im building at the moment so can't guarantee a quick turn around.

Hi guys, that's for all the fast replies.

The mech says it will be difficult to get new piston rings.

Anyone know if engine additives are of any use?

whats the most damage a faulty thermostat could do over a period of time?

Piston rings are readily available mate, David silvers sell them the price is per piston
http://www.davidsilverspares.co.uk/CBR4 ... art_11033/

Faulty thermo over time will not cool your engine so will keep blowing head gaskets and damage internals of the engine i.e warp the casings due to it being hot all the time. (seen it happen before when a mate came to me to fix his bike and had to get a new engine due to it warping cause he didn't bother replacing thermo)

petrolhead19 wrote:Piston rings are readily available mate, David silvers sell them the price is per piston
http://www.davidsilverspares.co.uk/CBR4 ... art_11033/

Faulty thermo over time will not cool your engine so will keep blowing head gaskets and damage internals of the engine i.e warp the casings due to it being hot all the time. (seen it happen before when a mate came to me to fix his bike and had to get a new engine due to it warping cause he didn't bother replacing thermo)

urgh dammit, should have fixed the thermo early on then... might have saved the hassle...

im based in Singapore, not the UK actually... will probably have to get it shipped over if i cant find the spares at my local honda spares dealer

thanks for your insights man... at least im not so confused now

In that case Cmsnl sell the piston rings you need and they ship world wide iirc
http://www.cmsnl.com/honda-cbr400rrk-nc ... 011ml0000/

That item is suspended by a newer version.
http://www.cmsnl.com/products/ring-set- ... 011mv4305/

Again price is per piston, and they are normally pretty quick on delivery.
David silvers gets there parts from this company so its the same original item.

We send Honda CBR400 parts to Singapore most weeks ....

Just email or call me ... in Mandarin is fine if that helps.

Both new and used rings in stock - genuine parts.

Cheers