Bike needs a lot of effort to kick over.

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
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Bike needs a lot of effort to kick over.

Postby Croweater » Mon Apr 01, 2019 8:55 am

Hi all,

Just a bit of history on the bike.

It's an AJ Model 18 that my grandfather raced back in the fifties here in Australia. He restored it back in about 2001 and it running like a dream.

I rode it just once just after he'd restored it and I didn't notice anything unusual in kicking it over. Having said that, my normal ride back then was a kickstart Harley Shovelhead so I'm wondering if it just seemed 'normal' to me.

My grandfather passed away not long after and the bike got caught up in contested will hassles for the past 15 years or so. I know a couple members of this bike club have tinkered with it in that time but I've got no idea what's been done to it.

Fast forward to now and I've finally got full possession of the bike. I've taken to my local British bike gurus to give it the once over and they can't work out why it's so physically hard to kick over. They even had a friend of there's with a G80 come over to compare it to and my bike needs so much more leg effort to kick over. We've pulled the plug and kicked it over and it doesn't feel overly sticky or restricted.

It starts, it runs (just), but it's a pain in the neck to ride because it's like kicking starting a Sherman Tank.

Before I pull the head and start checking compression etc, I thought I'd pop a post here and see if any of you have experienced this? Are we missing something simple?

Any clues would be greatly appreciated.

Cheers
Scotty

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Re: Bike needs a lot of effort to kick over.

Postby Mick D » Mon Apr 01, 2019 9:43 am

Hi

Does it have the valve lifter installed?

Does it work?

Are you using it?

If you can start the bike and it runs with oil circulating I'd run it for a while and see how it frees up.

Have a look own the spark plug hole - does the piston have a high crown indicating it may be a higher compression piston than standard?

Regards Mick

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Re: Bike needs a lot of effort to kick over.

Postby Croweater » Mon Apr 01, 2019 9:53 am

Hi Mick,

Yep, decompression lever works and I use it.

I'm heading in to see the mechanics in a couple of days. I'll let you know if they've checked inside cylinder. I'm assuming they have.

Thanks for getting back to me..

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Re: Bike needs a lot of effort to kick over.

Postby Rob Harknett » Mon Apr 01, 2019 5:47 pm

Did you turn the engine over until the piston is on the down stroke, then kick it.

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Re: Bike needs a lot of effort to kick over.

Postby George Kaplan » Mon Apr 01, 2019 7:00 pm

First, take the plug out and see if it is still hard to kick over. If it isn't then its just the compression and you need to look at the decompressor as mentioned above.

If its still hard to kick over then its a matter of eliminating things one at a time. Things that spring to mind are a sump full of oil, gearbox problem, clutch problem. I would start by taking off the primary chain and see how hard it is to move the engine with the plug still removed. If OK then how hard is it to operate the kickstart with no primary chain connected. And so on until you identify the source of the problem.

John

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Re: Bike needs a lot of effort to kick over.

Postby Duncan » Mon Apr 01, 2019 7:23 pm

Croweater wrote:It's an AJ Model 18 that my grandfather raced back in the fifties here in Australia.


High compression piston?

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Re: Bike needs a lot of effort to kick over.

Postby cbranni » Mon Apr 01, 2019 8:08 pm

Is it only stiff on the compression stroke? or stiff all round?
only dead fish go with the flow

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Re: Bike needs a lot of effort to kick over.

Postby Croweater » Thu Apr 04, 2019 7:45 am

Just got back from the mechanic and the news isn't positive.

I was able to compare it to a G80 he had in the shop. Not only is mine noticeably harder to kick over but you can hear a slight grinding noise when you do compared to the Matchy. It's not wet sumping and it's still tight when you remove the spark plug. The mechanic thinks it could be a few things. Bottom end bearing being probably the worst of them.

I'm going to pick the bike up, bring it home and strip it down. Will definitely pull the primary chain and confirm the engine's the problem not the tranny.

I've just ordered the Clymer and Haycraft manual but I've got no doubt I'll be a regular on this forum in upcoming weeks.

Thanks for your help so far and I'll keep you updated.

Here's a pic of the bike for interest sake.

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Re: Bike needs a lot of effort to kick over.

Postby Croweater » Thu Apr 04, 2019 8:02 am

Image
Image

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Re: Bike needs a lot of effort to kick over.

Postby Mick D » Thu Apr 04, 2019 8:10 am

Hi

No need to remove the primary chain to carry out first diagnosis of a transmission fault, just pull the clutch in and kick over, you are still turning the transmission but not the engine.

Nice bike

Lots of info available in the archives:

http://archives.jampot.dk/

Regards Mick

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