JHa Pipes or Not?

**Thu Mar 12, 2009 2:32 pm » Post: #1 » Download Post**

Gents,

My 1991 MC21SE has stock pipes, K&N filters in place of the stock air box, slightly larger main jets, stock slow jets, is running the power jets, has the HRC black box, stock oil pump and runs very strong from mid-range to top end. It's a little rough at idle and low RPMs and is a complete bitch to start but overall runs like crazy.

I have a set of JHa pipes that I have considered putting on it. Based upon your experience, should I put the JHa pipes on or leave it alone since it already runs so well.

Thanks,
Skunkbait

**Thu Mar 12, 2009 3:31 pm » Post: #2 » Download Post**

What you will really gain with the Jha's more than anything else is a weight saving and convenience of being able to remove them quickly/easily for maintenance. If they are stainless (most are mild steel though) they will also look great! Laughing

Your symptoms sound very much like my MC21 when the centre crank seal died.
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Andy.
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**Thu Mar 12, 2009 4:50 pm » Post: #3 » Download Post**

Andy,

Thanks for the advice.

How difficult is it to replace the crank seal and where can I purchase one? I'd also like to do a top end rebuild. Where can I find the parts?

Skunkbait

**Thu Mar 12, 2009 5:15 pm » Post: #4 » Download Post**

It depends. The more common failure seems to be the big O-ring around the centre main crank bearing. These are available individually and very cheap. However, if it's the main crank seal that's gone then it's either a crank rebuild (if you can source the parts and have a good builder) or a replacement crank.

You'll need to search the forum for info on cranks and how to test the seals, and to read about other members experiences to see if it applies to your case.
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Andy.
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