Timing way out 350 Sport 1979 ?

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Matt Hale
Posts: 75
Joined: 08 Oct 2020 10:00
Location: London

Timing way out 350 Sport 1979 ?

Post by Matt Hale »

Hi Everyone
I recently joined MRC but have had a 1979 350 Sport-electric start model (but starter is not fitted) for quite a few years...15+
I have recently been fiddle-fettling and have hit a non starting situation. Fuel is coming out of the wrong end of the carbs when I kick it over and none is getting into the engine.
I have changed the cam belt and wonder if I have the timing completely wrong- so wrong the inlet valves are not open at the correct time? If this was the case would it turn over? I have the marks on the cogs the belt runs on correct and have not removed these so they are as was- but can they be lined up but actually completely wrong?
I have stripped carbs and all air/fuel ways seem clear, needles E17-on middle groove and jets correct sizes and clear. There are sparks at the plugs but they remain very dry...
I have checked the valve clearances but could I have done that with pistons at TDC at wrong time- the tappets seemed loose/open when I did check..
Any thoughts and advice on where I should most spend my time very welcome..
Thanks in advance

Best to all !
Matt
350 Sport 1979 electric start model (missing)
Curry yellow tank etc paint work, navy blue frame, silver wheels.
mbmm350s
Posts: 666
Joined: 22 Jun 2018 10:18
Location: Reading UK
Location: Berkshire UK

Re: Timing way out 350 Sport 1979 ?

Post by mbmm350s »

Hi Matt,

First of all welcome to the forum!

Some questions.

1. Was the bike running before you changed the cambelt?
2. Did you move the cam pulleys independently of each other at all when replacing the belt.
3. can you post a picture of the cam pulley positions with rotor removed- with engine at TDC front cylinder.
3. Did you at any time remove the pickup rotor (it could be 180 degrees misplaced )
It should be placed so that the cutaway part is facing No1 cylinder at TDC which is towards the rear (page 23 of the manual)
You can follow the valve sequence to know which revolution is TDC front cylinder compression stroke.

The timing(ANT1) and reference TDC (PMS1 and PMS2) marks on the rotor for electric start models was moved from that of non electric start models.
You say there is no e-start - do you have an e-start rotor(with dish or with dish cut off), or a non e-start rotor?
(In the 80s the electric starts were sometimes removed by owners and rotors substituted so the smaller case could be used)
If you see page 14 of the manual it shows the different locations for e-start (new models) and non e-start(older models)

Hope that helps
Mark
Matt Hale
Posts: 75
Joined: 08 Oct 2020 10:00
Location: London

Re: Timing way out 350 Sport 1979 ?

Post by Matt Hale »

H Mark
Many thanks for your time writing back to me. I checked you point 2." Did you move the cam pulleys independently of each other at all when replacing the belt" and I think I had moved them independently. Checked TDC at front when in correct position with the marks on both cam pulleys and she started first kick no choke! Before I'd changed the belt the bike started fine but it was a while ago as I have also had to take the clutch out and put kick start mechanism right which it is now. I am just awaiting new chokes and idea jets and then I'll carb tune it and get it as perfect as I can!
I had removed the pick up also when doing the clutch but had put that back correctly!
Many thanks again and great to have this club resource for problems- bit stuck and lonely when they arise otherwise !!
Best to all
Matt
350 Sport 1979 electric start model (missing)
Curry yellow tank etc paint work, navy blue frame, silver wheels.
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