The 'other' blown up RGV250: A question

MarJay · But it's British! Joined: 15 Sep 2003 Karma :

Hullo,

As many of you may know, Gooses was not the only RGV250 to blow up this summer.

Mine destroyed a sparkplug at Cadwell park. It somehow bent the side electrode over to touch the centre electrode.

Not good.

The piston is now marked, but perfectly servicable. I took the head off a few weeks ago and inspected it. The bores are ok, the head is fine, and everything else looks fine.

I stuck a new plug in the head, and today I finally got around to starting 'er up. She runs, but she also makes a very loud intermittent scraping noise.

Keith has commented already that the piston hitting the plug could have been caused by a bearing gone (either big end or small end).

Is the noise I described consistent with this? Confused

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rpg · Scooby Slapper Joined: 08 Jun 2005 Karma :

hi, i dont know if a head gasket is used on your bike, but if left out on bikes that need them it causes very high compression, which causes "pinking" or "detonation" with lower octane petrols of today. Also, no head gasket when needed can cause the piston to hit the spark plug, as the gasket "packs out" the space known as a squish, which is needed to stop the piston hitting either the top of the cylinder head or the plug.
many thanks.

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Mark

I would say take the barrels off and check the pistons (you are most of the way there already) and check for play in the con rods.

All the best

Keith
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hmmmnz · Super Spammer Joined: 22 Aug 2006 Karma :

have you talked to the guys on https://www.rgv250.co.uk/forums/
they all know there stuff,
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MarJay · But it's British! Joined: 15 Sep 2003 Karma :

WildGoose · White Van Man Joined: 21 Mar 2002 Karma :

Robby · Dirty Old Man Joined: 16 May 2002 Karma :

sickpup · Old Timer Joined: 21 Apr 2004 Karma :

If either RGV are track bike I recommend getting one of these clicky

Jack_Cheese · World Chat Champion Joined: 14 Jul 2005 Karma :

That plug was absolutely shamless! Laughing

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sickpup · Old Timer Joined: 21 Apr 2004 Karma :

I thought it was quite subtle. In fact very subtle, almost as subtle as a very subtle thing thats been hidden away from prying eyes for over a thousand years.

whereas this...

Clicky

is less subtle. Laughing

MarJay · But it's British! Joined: 15 Sep 2003 Karma :

Robby · Dirty Old Man Joined: 16 May 2002 Karma :

Definately lower the gearing, its a cunt as is.

Of course, you really want a nice cheap (£1400) SV to hone your wheelie skills on first. The sort I'm selling.