My bike hates me!

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
Member
User avatar
Posts: 168
Joined: Mon May 01, 2017 6:32 pm
Location: Lancashire

Re: My bike hates me!

Postby spookefoote1956 » Thu Aug 24, 2017 10:39 am

MikeM. wrote:I have had problems with Halfords acrylic paint seemingly separating and leaving deep edging groves, I have bought old stock Holts paint from Kempton and that seems to be ok.


I've reviewed the paint on their website, which should appear in a couple of days. It wasn't very complementary. The funny thing is it was fine for about a month and looked really good. The lacquer was great and absolutely pinged. I was really proud of it and if you have seen the photos I posted can see how good it looked. P**sed off aint the half of it!
Hail Joe Lucas ............ Prince of Darkness!

Member
User avatar
Posts: 168
Joined: Mon May 01, 2017 6:32 pm
Location: Lancashire

Re: My bike hates me!

Postby spookefoote1956 » Thu Aug 24, 2017 4:05 pm

So the dots are right 2 inlet 1 exhaust. The pushrods are set right on the tappets. Bike in 4th, watch the inlet pushrod go up waiting for tdc, rotate wheel back to get to 1/2" before, fully advanced on the adv/ret then move the magnet round on the thorspark to the firing mark (obviously on a mag that would be where the points are opening).

Am I doing something wrong? I get a quick bang (lucky me) then nowt. Have I got it on the right stroke? How do I know? I know I'm sounding a bit thick now but I've tried everything.

The engine's 56 so the timing dots should be 2 inlet 1 exhaust as per the manual.

My other stupid question is about the number dots on the cams. Are the numbers in the same position on all cams from 1947 up?
Hail Joe Lucas ............ Prince of Darkness!

Member
User avatar
Posts: 166
Joined: Sat Dec 17, 2016 5:26 pm
Location: Taunton somerset

Re: My bike hates me!

Postby Harry44 » Thu Aug 24, 2017 9:36 pm

Firing should be 1/2 inch BTDC on the compression stroke ie both valves shut
si is does non opportunus vos postulo a maior pango

Member
User avatar
Posts: 548
Joined: Thu Nov 12, 2015 2:22 pm
Location: Florida, USA

Re: My bike hates me!

Postby Expat » Thu Aug 24, 2017 10:54 pm

Chris, it sounds like you need to rotate the engine once more. Agree with Harry.

When the inlet push rod goes up the valve is opening. Then the piston has to go down, drawing in the mixture, inlet valve closes and piston goes past bottom dead centre. Or the other way round but that's basically the idea :lol:


Then piston comes up on the next stroke to compress the charge ready to be ignited. :D

Sorry if this is obvious but that's how it seems to me. :)

Steve
Keep shiny side up.

Member
Posts: 506
Joined: Mon Jan 01, 1990 12:00 am
Location: LANCASHIRE UK

Re: My bike hates me!

Postby zwarts » Fri Aug 25, 2017 9:32 am

Chris, do you not have anyone nearby who could help you out here? Reading through this post, I think you will continue to struggle until you get help from someone who has some experience with engines in general and AMC in particular. Setting valve and ignition timing are such basic but fundamentally important processes that they just have to be correct. You seem to be a bit out of your depth here and it might be expeditious to get experienced help!
You were trying to set the ign timing on the wrong stroke and there is some doubt about the exact firing point with the Thorspark unit. Setting valve timing is best done from first principles without any dependence on timing marks, whatever cams are in use.

Member
User avatar
Posts: 168
Joined: Mon May 01, 2017 6:32 pm
Location: Lancashire

Re: My bike hates me!

Postby spookefoote1956 » Fri Aug 25, 2017 11:41 am

Zwarts, you are right. I am now at the point where my head is spinning and I cannot seem to do the right thing. Obviously I'm miffed at the paintwork and this is affecting my judgement.

If there is anyone in the Lytham St Annes area who can pop round and help me with this then please send me a PM so we can arrange a session. A bottle of Scotch or whatever is your chosen tincture is on offer to the person who can successfully see me over this hurdle.
Hail Joe Lucas ............ Prince of Darkness!

Previous

Return to G80 / Model 18

Who is online

Users browsing this forum: No registered users and 4 guests