Pattern Head Gasket

mj43 · Post by **mj43** » Fri Apr 02, 2010 8:18 pm

Just put a motor together for Andy B. It has an engine I did some time ago so just brought the crankcase work up to date and did a little work on the transfer tunnels.

When it came to assembly time put barrels to head as I always do. Power valves locked up. Mmm... How ever I tried bolting them together - same problem. Got Andy to send me a stock head gasket as I was using a pattern part that came with the kit he supplied (note water pump and gear change cover gaskets aren't part of the kit?)
Fitted stock gasket - no problems

Had a look at pattern gasket and stock gasket (before I put it in). The gasket has an indent where the powervalves are. On the stock gasket the indent is up, on the pattern part down? Yes I did check UP on both was UP. Conclusion is that the pattern gasket was jamming the powervalve - making them very tight to turn. I may try the gasket upside down on a spare set of barrels to see if that fixes the problem.

Leewc · Post by **Leewc** » Sat Apr 03, 2010 7:20 pm

Best to always use an OEM gasket then?

Charles · Post by **Charles** » Sat Apr 03, 2010 7:20 pm

Leewc wrote:Best to always use an OEM gasket then?

most people do.

spannerman · Post by **spannerman** » Sat Apr 03, 2010 8:58 pm

i have had this problem with the pattern gasket mark, think it should be ok upside down but never tried it just kept using the old one with some h***a as you told me to do at cadwell.
ade.

maccas · Post by **maccas** » Sun Apr 04, 2010 12:18 pm

i also had this problem too, i noticed the lack of those two gaskets aswell

Cexley · Post by **Cexley** » Fri Apr 09, 2010 9:49 pm

I put a post up about this a few months back called 'Top End Tips'. I had the same problem with the indents vs being stamped 'UP'. I fitted it with 'UP' down and everything worked fine. However, my latest post re KIPS valves could be as a result of this! I now seem to be suffering from chattering KIPS valves, but no one has confirmed or denied this is a 'feature' on KR1's. Anyway, head gasket itself has been fine fitted upside down.

mj43 · Post by **mj43** » Sat Apr 10, 2010 7:10 am

Didn't see that post.
I have always used stock gaskets so not come across this before. Still a day older and a tadge wiser

The valves always seem to bounce up and down. Some bikes are worse than others. Also depends on how worn things are.

Cexley · Post by **Cexley** » Sat Apr 10, 2010 11:59 am

LIkewise. Every day is a school day.

I really can't figure whether it is the KIPS valves, or piston slap/small end. It is a 'tinking' sound (a bit like an engine pinking) when going along at about 5-6k. It doesn't do it under load or when I wind it up to the red line, but comes back with a vengeance on the overrun.

I really don't want to strip the engine again only to find it was the KIPS valves rattling. As I have never had a KR1 before, and none of my mates have one I can compare against, I am not sure if this is 'normal' or not.

The motorcross forums all go on about how noisy KIPS valves are on Kwak crossers, which they do from new.

As you know these bikes inside out, so what is your take? Craig