Non starting 1990 SR42
Where do I start?
I have been rebuilding a 1990 SR42 that I have found out has a chequered past on this forum when in the ownership of GrahamSWTRF , basically he couldn’t get it started.
I like a challenge and having retired early in order to accomplish my dream of becoming ‘an old git in a shed’ surrounded by bikes and machinery I took on the challenge .... and the bike is stumping me as well now!

Things I have found that I initially thought would be the cause of the ‘non starting’
1. The coil for ignition was dead, this has been re-wound by West Country Windings.
2. Springs missing from air screws on Carbs – springs added and screws reset.

Having had the bike in bits I have checked everything I can. I have had the head off, valves are good, no holes in the piston, CCT seems to function fine. The one thing that I did notice was that when setting the cam timing I was unable to perfectly line up the marks with the face on the head, one either pulled down very slightly or up very slightly depending on which tooth I set in the cam chain. The cam chain is well within the tolerances given in the WS manual. I have reset the decomp lever.

On the ignition side the coil has been re-wound, the coils and pick up coil check out according to the WS manual. I have swapped CDI’s just in case. The spark I am seeing is not the best I have ever seen but is nice and white (both plugs). I have traced through all the cables and cleaned/re-terminated as necessary.

On the carbs I have had them apart, checked and cleaned them and set the float level with the ‘wet method’.
In trying to get the bike started (it turns over fine and the decomp lever clicks off) I have connected a dummy tank and fed the fuel directly to the carbs. I have sealed the vacuum hose. Is this correct?

So a couple of questions, first the obvious one ‘why won’t it start’?
Other questions, ‘what have I missed?’ & ‘does this motor run a lost spark?’ – this is a bit desperate but I’m just wondering if the timing can be 360 degrees out.
Sorry for the length of a ‘first post’ but as a Mod on another bike forum I know a bit of detail helps in diagnosing issues, perhaps not this much but when I get started ........!

Anyway here is my bike as it stands today
Well I got it started after a bit more fettling...… and to prove the point The lazer can is a tad loud!
Nearly back together now with some new paint.
That's great I like the idea of that fuel bottle you are using I could do with one of those as the Big's tank is a bit of a monster. What was the problem in the end?
GrahamW Wrote:That's great I like the idea of that fuel bottle you are using I could do with one of those as the Big's tank is a bit of a monster. What was the problem in the end?
Not 100% sure, I pulled all the electrics again and retested. When I was happy with that and had sparks that jumped 8mm on my tester I went back to the carbs and set the flaps at zero clearance (hence the lack of idle) to ensure the choke was operating at top efficiency …………. and it fired first time!

Yes I like that temp tank as well, for years I made do with a 'lash up' and when it started to fall apart I bought that one for a few £.
BigBob Wrote:Thumbup
Thanks BigBob, appreciated.

I've been a 'lurker' here for some time mentally grabbing as much valuable info as I could. I would have registered earlier (and no doubt asked dumb questions) but had problems registering with the forum (never got an Email) in spite of 4 different attempts, I almost gave up. I even donated 1p to see if that helped :D A good escape for all concerned!

In spite of many years of 'spannering' this bike has taught me so much I feel I owe it rather than the other way round.
There are a lot of lockouts on the DR I have found that stop it starting and turning over, a switch in the decomp lever and clutch lever. I have found that out while trying to get mine to turn over with the starter initially suspecting the starter switch was broken.
Well the bike is back on the road, passed it MOT last week. Confusedhock:

The bike fought me to the end, I booked it in for an MOT a couple of weeks previously and never got there!
With the control positions being in alien positions to me when I reached some traffic lights after half a mile I decided to leave it in first, mistake! After 20 seconds or so I felt the clutch grabbing so I held it on the front brake, mistake! Suddenly the bike lurched forwards and over we went. Walk home, pick up van and into the back it went. So glad for the crash bars they saved the paint and with a blasting off and some powder they are like new.
The clutch was 'interesting' I pulled it when I bought the bike and checked it through, all well in spec. On pulling apart 3 of the plates were stuck, seems it didn't like being left to stand for a year. New cable just for the hell of it (the old one moved smoothly but nothing like a new one). This time I ratchet strapped the bike to the stand and ran it through the gears, all correct and present Thumbup

Sailed through the MOT.

Looking forwards to adding some miles to the bike now but since I'm heading off to the Balkans on another bike in a few days time I will just have to wait.
Well done on the perseverance you have a very tidy looking bike there Thumbup
Keep the loud can, it's great fun setting off over sensitive car alarms.
I have my wife's permission to keep breathing!! Big Grin

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