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Discussion Starter · #1 ·
I have seen 2 types of Vertex pistons available online for the GFR,both are £70 one is double ring and the other is single ring. Does anyone know if these Vertex ones are any good or should I try finding an original piston? Any help would be much appreciated...my GFR was siezed/overheated by the previous owner and he says there was not much water in it when he checked,it seems to have compression still but battery is flat. He seems to think it needs a new piston and rings...
 

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Discussion Starter · #3 ·
Oh it wasn't a proper test I just pushed it forwards slightly while in gear,piston is moving but there's a bit of a noise there. I've been trying to take the fairing off today but quite a few rounded out Alan heads stopping me,so It's all just hanging off..I can get to the head and barrel from the left hand side now...think I might have to lift the tank up to actually remove the barrel though,It's the first time I have ever touched a GFR
 

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Discussion Starter · #4 ·
Does anyone happen to know which pistons are any good in the GFR? I'm thinking about trying to get an original from Bob Wright or from Italy but 70 pounds for a Vertex from PJME I think sounds reasonable...
 

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Vertex are a quality manufacturer. I would get the bore measured for ovality if its been seized, will probably need a hone in any case which would sort that out easy enough.

Was it badly damaged?
 

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Discussion Starter · #6 ·
Hi the Old Painless,the previous owner said it siezed/overheated/cut out lol...I have had it running and been out on it for only a few minutes...but the coolant was boiling,the thermostat might be gone,I can't find any leaks. I've been told they have a thermostat in the bottom of the radiator and on top of head.Cheers for any advice
 

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First thing would be to find the cause of the boiling coolant, possible causes include:
  1. Low coolant level
  2. Head gasket leak
  3. Coolant system leak
If nothing seems to be wrong but it is overheating after a while and take a long time to cool, it may be the coolant is not filling the system properly.

If your losing coolant and the reservoir smells funny, has an oily film, looks rainbow coloured or has bubbles coming up in it the head gasket is gone.

If your losing collant and you find water dripping out or a collection of crystals where the coolant is coming out and evaporating your coolant system is leaking and is not pressurising which allows it to boil.
If your gear oil dipstick is covered in white mayonnaise looking gunk the water pump seal may be gone, i presume the GFR has one.

Hope that helps.
 

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Discussion Starter · #8 ·
Thank you,I saw/smelt fumes bubbling out the header tank...I replaced the head gasket and then the radiator started leaking! So I have ordered one and it's currently on the way to me.
 

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The GFR cooling system is notorious for getting air locks if incorrectly filled. Take your time refilling the system and run it for a while with the cap off. Make sure you get the recommended quantity of coolant in there. One of mine seized because the previous owner didn't do it correctly. Even though the exoansion tank was at a correct level, when I drained it after the seize there was half the coolant in it there should have been. There definitely weren't any leaks and the head gasket wasn't blown.

Follow the link in my PM about pistons for more info. Hope you get it running OK again - there aren't many left! If you don't mind me asking - where did you get it?
 

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Discussion Starter · #10 ·
I got it from Leicester...I've wanted one since I was 17,finally got one 13 years later! It has gold wheels but not sure why because all the others seem to be black. I want a Crono and maybe an NSR with a bigger cylinder next. Are there any kits for a GFR? I heard Hahne power made a 168cc Crono.
 
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