Well, my Scott has reincarnated! Yesterday the bike was finally ready after 4 months of engine work! Now is the moment to see what the “Moss style” gasflowing will do! Just in time for next weeks track sessions….
BUT…it does not run!!!!!
I’ve tried anything but nothing works.. The bike does not give one single sign of life! I’ve tried:
mopping out the wells: they were filled with oil (I squirted some in while assembling) and petrol (after prolonged trying). So the bike must at least get petroll
fuel flow: the fuel flows very well. But even after trying for quite some time the plugs are almost completely dry…Brake cleaner in the carb or even directly in the cylinder does not work either
the ignition: is set at 30 degrees and there is a decent spark (outside the cylinder). With 0,007 to 0,012″ sparkplug gap the bike does not fire. In all my work on the bike I did not touch the magneto at all. The bike was very easy starter before (2-3 kicks). I’ve checked and cleaned the points and tried with and without cover (to rule out the cutout switch)…. nothing
no leaks to be seen anywhere
we have tried kickstarting and pushing
I’m at my wits end and don’t know what to do. Any hints????
i’ve just been through a similar experience with a newly rebuilt engine and had to do three things – prime the crankcase glands with oil to ensure the cranks were air tight, squirt a tiny amount of flammable spray mist (i used wd40 aerosol) in the cylinders and open the plug gaps upto about 30 thou to cope with flooding. Eventually my machine started and now it starts after a couple of kicks.
Best of luck,
I trust that you have the ignition leads on the right plugs? Try swopping them over. Also squirt some oil down the plug holes to seal the rings – it often works.
Thanks guys for the replies!
The plug leads have not been swapped. When I bought my Scott I tiewrapped the leads to the frame to prevent mistakes. The Scott ran fine and since then I did not remove the tiewraps. So that’s not the solution.
I’ve tried the starter spray but with no result. But the reason for this might well be that the cases were quite flooded by then as I noticed later. I did not try the spray later (yet).
What worries me most is that the plugs stay almost completely dry after prolonged trying. On full choke and after excessive flooding of the floatchamber they should be at least wet. So my best guess is still the fuel supply. Even when using two high flow taps.
So today I’ll take of the tank and carb again and do some checking and measuring. I’ll try the WD40 again wihout the carb on the bike. That should work. I’ll also try the squirt of oil in the cylinder.
Fingers crossed and hope for the best!
Keep you posted!
At this moment I really don’t know where to look anymore. After another whole day in the workshop I’ve about checked everything…twice!
I’ve disassembled and cleaned the carb and checked the fuelflow. All ok. I tried several plugs with several gaps. I switched the plug leads, checked and cleaned the HT pickups (the carbon brushes looked rather short..). Drained the crankcase wells again (lot of petrol in it) and tried WD 40 and brake cleaner several times.
All of this with no result at all! The last few days I got 4 loud bangs in the exhaust in total that’s all… What can it be?
While checking the spark while trying to start I used my timing light (stroboscoop). I seemed that the sparks were not always regular. But on the other hand, it’s very difficult to measure on the kickstarter. And the mag never gave me any problems in the past at all!
The only thing I can imagine being wrong is a very serious airleak somewhere. Everything is sealed with silicone sealant in combination with O-rings or original SOC gaskets were appropiate. I cannot check for leaks with the spray on WD40 method as the engine does not run. Any ideas on this?
Hio just a thought from many years ago after my father rebuilt his scott 500 squirrel, someone mentioned ensuring the lands were oiled to ensure a seal, this problem existed with the rebuild mentioned but only on one cylinder the cure for that one one to force oil through the feed to the main bearings and the lands by using an oil can to force oil through the pipes from the pump. Worth a try.
About five people have in between mentioned switching the leads. All indepently. That is not without good reason I guess…
I did try switching leads this weekend but only briefly. Maybe the casing was already flooded and therefore the engine did not start, even with the leads switched. I think, while working on the bike, I must have turned the cam 180 degrees and not knowing it….
This evening I’m DEFINITELY going to try it once more…
Come back here to read the results!
Well, it were the leads indeed! During the rebuild I must have turned the magneto 180 degrees and not noticing it….
After swapping the engine sort of give a sign of life! Not for long… After some pushing it ran for half a minute and then stalled again. But, the tank was almost empty so I’m going to get some more petrol tomorrow and try again.
Here a little clip showing my sad attempts…
I’m on the right track now!
PS: On the way back from work a guy in a delivery van decided to back up right in front of me while waiting for the lights… My Yamaha SRX was drawn under the van and now has quite some damage. I just had it ready…. Luckily I could jump of in time. They should make those rearview cameras mandatory on vans with no rear window!
HURRAY, SHE RUNS!
Yesterday, with the help of the good old WD40, some more petrol and a friendly neighbour that helped pushing, the neighbourhood finally has a chance to hear the beautiful whispering sound of my Scott ;o)
Although she runs very much to rich I was able to take her for a quick spin to check if everything else was functioning. And it was. Even my magneto beltdrive conversion holds and runs very silent and true!
So far, I’m a happy biker!
Now, let’s just hope I can get the jetting sort of sorted out today (thanks Alfred for the excellent accessibility…..) so I can make a good impression on track this weekend.
Keep you posted!
Last evening I changed my jet for a smaller one (230, remember moss style engine) and lowered the needle a notch. In the process I dropped a small tool and a nut in the casing…. I guess we have all had the pleasure of getting something out of there. Well, my pleasure took several hours…
So, as I did not have the opportunity to take the bike for a spin yesterday I took it to work today. Downjetting makes a great difference. The bike now pulls the longer gearratio (22 T on flywheel, 21 T on outrigger) with ease and also rides a lot better in second. Third still feels like an “overdrive”. I do think the engine still is to rich as it won’t rev very high and the plugs are rather dark. So I’ll try a 210 tonight.
We’re getting there!