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New member

Post by Harrisg80 » Tue Sep 18, 2018 6:10 pm

Hi. I have just joined. I live in n.Wales not far from Chester and do not have an mt..
I often considered one but have bought a Harris g80 with a similar motor
Sadly it has lost compression after only 100 ml so I am seeking knowledge from members
I suspect burnt valves or a blown head gasket but favour valves as the clearance was less than nil on the inlets having seen the fiddle to revive the rear rocker cover it is not surprising they are too tight!
Still low compression after adjustment!!
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Re: New member

Post by sparky » Tue Sep 18, 2018 6:28 pm

Hello and welcome. Have you checked that the valve lifter is properly adjusted?
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Re: New member

Post by Minter » Tue Sep 18, 2018 9:13 pm

Hi Harry

Welcome to the forum. Give us a call at Sportax tomorrow, we are based near Telford now so not too far if you get stuck.

We specialise on these Rotax engines.

Have you tried a compression test? Is the valve timing and pulleys and belt ok? And as mentioned by sparky the valve lifter mechanism serviceable?

Hope that helps

Sportax Racing
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Re: New member

Post by Force Motorcycles » Wed Sep 19, 2018 11:15 am

Welcome to the forum :)

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Re: New member

Post by Harrisg80 » Wed Sep 19, 2018 6:01 pm

Thanks for the welcome and advice.
I took the tappet covers off last night and found the inlets were tight. Not surprised really as that back bolt is a swine to least on the Harris!
The valve lifter had clearance so seemed fine.
Today I checked the valve timing as I thought I could hear the belt striking it's housing at times.
The previous owner had changed the dayco belt but I suspect he did not tighten it suffciently as it appeared to be two teeth out of sync
I retimed it,nipped up the valves by hand then fired it up.
Compression is back and it sounded fruitier than previously Result!!
Tomorrow I will set the clearances properly,refit the tank etc and test.
I have only done 100 ml on it but love the thing. So stable and smooth.
Much better than the speedtwin I swopped it for..shame I have to pay ved and mot though!!
The experience makes me want a can am or HD but one bike is now enough having downsized from seven!
Next job will be an oil change,rectify wiring issues..maybe a new regulated as I get 14.62v on my meter when revved,and also a spoke as one is broken!
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Re: New member

Post by appyarry » Thu Sep 20, 2018 11:38 am

Harrisg80 wrote: ↑
Wed Sep 19, 2018 6:01 pm
rectify wiring issues..maybe a new regulated as I get 14.62v on my meter when revved
I'd be happy with that voltage on the reg/rectifier :-)

Good Luck,
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Re: New member

Post by Harrisg80 » Thu Sep 20, 2018 12:19 pm

Maybe so. It just seemed a bit high to me. I need to sort the electrics as the L/h switch appears to have failed.
I had lights then just the side light and headlight flasher.
They are magura hence hard to get,plus they incorporate the valve lifter mount.
Anyway,I tested the bike a.m. today and all is well.
Revs better but somehow it seems the Speedo doesn't keep up!
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Re: New member

Post by Fergie » Sat Sep 22, 2018 9:13 pm

Welcome to the forum, from another Harris G80 owner (as well as MT350s and MZs).


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