Timing Question ... 18 or 20 pins gap..Help needed

[Guest]

Hello All, Not posted for a while, but currently rebuilding a 1980 GS450S into a Cafe Racer Style Bike.. Engine has been stripped to last nut and bolt Carbs vapour blasted and engine painted Black with polished outer cases.. Pics to follow for those that are interested..

Timing question, When I stripped the engine, I was careful to mark everything timing related and made notes too of where everything went.. But upon reassembly, I discovered that the workshop manual states that there should be 20 pins between the camshaft timing arrows ... But when I took it apart there were only 18 pins between the marks.. You can see that the marks I made align in the first pics (pre-stripdown) but naturally no longer do if I rotate the camshafts to accomodate 20 pins .. See lower pics for where the marks are now.. I Installed tensioner and slowly rotated engine and on the 20 pin setting, no clearance issues, all seems as it should.. But nervous now as to whether to go with Manual settings, or stick to how it was when I found it..

Bearing in mind the engine ran poorly before I took it apart, put that down to bad vacuum on the carbs/airbox and bout new boots/rubbers etc.. Advice/opinion would be well received before I continue

PRE-Stripdown










AFTER Rebuild - Black marks on Valve cappings no longer aligned

[tkent02]

It's not uncommon to have the cams put in wrong by some previous owner, looks like this may be the case. I can't remember if it's 18 or 20 pins for the 450, but if you are using the Suzuki Service Manual and not some bogus Clymer or Haynes, and if it's the one for your engine, I'd do it like the book says and not worry about what the PO did. That last picture is poorly lit and poorly focused, but from what I can see it's not correct. I just looked in the service manual, it's supposed to be 18 pins on the 450, not 20.

[tkent02]

OK, now I remember, there is no Suzuki manual on Cliff's site for the 450, only the Clymers. It shows 20 pins for the 400 and 425, but 18 pins for the 450.

I was not able to find a Suzuki manual when I put mine together a few months ago, used the 18 from the Clymer's manual and it runs fine. Still haven't found a Suzuki Service Manual for this bike.

[Showtime]

OK, now I remember, there is no Suzuki manual on Cliff's site for the 450, only the Clymers. It shows 20 pins for the 400 and 425, but 18 pins for the 450.

I was not able to find a Suzuki manual when I put mine together a few months ago, used the 18 from the Clymer's manual and it runs fine. Still haven't found a Suzuki Service Manual for this bike.

Hiya Tkent... appreciate the info, Yep it's an old Clymer manual.. hence my reluctance to follow it.. the tensioner is also completely different on the 450..

Going to go with the 18 Pins and put it back as I found it & marked it. Before I stripped it, It wouldn't rev on the throttle, ticked over fine so that's telling me the timing was OK but insufficient vacuum prevented the slides from lifting..

[tkent02]

It wouldn't rev on the throttle, ticked over fine so that's telling me the timing was OK but insufficient vacuum prevented the slides from lifting..

That would not be my first guess, what are you using for an intake? Airbox, pods, nothing at all?

[Showtime]

That would not be my first guess, what are you using for an intake? Airbox, pods, nothing at all?

Standard airbox, just bought new airbox boots, intake rubbers and new ' o' rings, not yet fitted but will be by the wekend.... to be fair it did seem to be fairly well sealed but just would not pick up on the throttle.. what's your thinking tkent

[tkent02]

All of the passages are open and the slides side freely? Is the slide spring kinked? Got a hole in a diaphragm?

[Showtime]

All of the passages are open and the slides side freely? Is the slide spring kinked? Got a hole in a diaphragm?

We'll see ... keep you posted.. I reset timing back to how I found It.. 18 pins.. much appreciate the input on that.. invaluable..Thankyou

[sam000lee]

This threw me off when I took the camshafts off my '81 450 a few weeks ago. It's 18 on mine, to give you some reassurance!

[Showtime]

This threw me off when I took the camshafts off my '81 450 a few weeks ago. It's 18 on mine, to give you some reassurance!

Thanks Sam.. I went with the 18 pin setting, I'm certain that's now right.. I can carry on the rebuild now..will post more pics later..