Engine over heated

[matty_boy]

Ok I am looking at buying a cheap bike that I have found, the guy says that the engine has over heated at some point in its life, and has a new water pump to be fitted.

He says the engine will start and run fine, but he has not taken it on a long run for ages to see if it still over heats. He has just run it up on the drive way and it has been fine.

So I want to know what you guys think about what damage might have happened to the engine if it has over heated? If any.

I am willing to pay up to £600 for the bike, it is a NC30. Nothing great but it will be used as a donor bike for my race bike that I am building at the moment, but I need the engine not to be trashed.

Ta Matty.

[wullvfr]

it depends on how much it overheated and how long it overheated for.

if it starts and runs fine when cold then it is most likely absolutely fine and undamaged.

usual overheating damage would be a warped head,which in turn would lead to poor compression and a blown gasket as it would no longer be seated and sealed properly.other damage would be internal engine components being fooked through being too hot,parts melting etc.

i would look out for any abnormal noises and sounds coming from the engine whilst started up.

first of all,you want to find out why it is overheating and rectify the problem.


william

[Neosophist]

The phrase how long is a piece of string comes to mind.

Since the bikes still running it hasn't overheated to the point of suicide.

check the oil and water and make sure the water still looks clear and the oil isn't creamy (signs of one leaking into the other, which would indicate a failing head gasket or other internal damage) also make sure that the exhaust stops steaming when the bikes fully warmed up, had one once that wouldn't stop steaming, a very tiny amount of water was getting into a cylinder.

What you need to remember is that overheating the engine stresses it beyond its designed operating proceduers and weaken parts like headgaskets etc, i've known engines to blow steam and be fine, then i've seen other engines suffer from a blown head-gasket 6 months down the line. Each engines going to be different depending on age of parts, how stressed their were etc.

If your planning on building a racebike i'd strip / clean / rebuild the engine just for peace of mind as the last thing you want is a hg or other internal failure when your flat out on the track.

Or you could just see if doesn't overheat, leave it as is and call yourself team dangerous or something :D

[matty_boy]

I already have one engine that needs to be fully striped and rebuilt which i will have done before my first race day as that wont be until next year.

I am after a engine that will be working so that i can get the bike ready for track days this year.

[hunter]

if it was me i would the spend £600 on the engine you'v got.

[matty_boy]

if it was me I would the spend £600 on the engine you've got.

Why?

Like I said in my first post I am buying the bike to be a donor for a race bike that I am building. I have a frame, forks, swing arm, rear shock, wheels, sorted carbs. All of these parts have been stripped and are at the powder coaters as we speak.

I need to donor bike for the rest of the parts, all of the little bolts and things that I might have missed.

On the engine side of things I have a engine that has been "tuned and quieting gears removed". I need to strip the engine and give it a FULL rebuild before I race it next year.

In the mean time I need I spare engine that I can just drop in to the frame to check that I have got the rest of the bike set up correctly.

But this post was to find out if any one has come across a engine that has over heated and died ????????

I have never head of a NC30 lump dieing due to it "cooking up".

Matty.

[wullvfr]

But this post was to find out if any one has come across a engine that has over heated and died ????????

I have never head of a NC30 lump dieing due to it "cooking up".

any engine left to heat up for too long would die and be buggered,but the fact it starts and runs fine to me say's it's ok.....so go ahead and get it.



william

[hunter]

sorry matty-boy,my misunderstanding thought you just wanted the engine,and i also i did not know that your engine has had the work done to it.thats why i said spend the £600 on it.

[matty_boy]

No worrys HUNTER, i am sure by the time i have finshed with the engine it will have more than £600 spent on it.