Barrel now painted with a high temperature engine paint. the paint says it is all right up to 600 degrees C, but i can’t think that the barrels would get hotter than 250 degrees.
I used to have a torque wrench, exactly like the one in the picture. The torque wrench with the giant needle pointing to the setting. I've lost track of it though, and am unsure where it can be...
The engine is in the frame, but the bike is off the bench as my daily ride has just blown a head gasket. In this pic the head has been placed on the barrel just to keep dust out. Someone has wandered in to inspect the bike.
just a note on that point set. the original 4CA unit you have was plagued with awkwardness. crowded, as you have seen, awkward to time because you have to fudge the points gap, and prone to bounce because of the cam. the bounce was an issue, because it caused stray sparks which resulted in preignition and detonation, and killed a lot of engines, as i understand it. a slightly later 6CA points plate will drop right in, will allow you to put the condendors somewhere cooler, will let you time each cylinder individually,
you appear to know exacgly what youbare doing. still, just a note on that point set. the original 4CA unit you have was plagued with awkwardness. crowded, as you have seen, awkward to time because you have to fudge the points gap, and prone to bounce because of the cam. the bounce was an issue, because it caused stray sparks which caused preignition and detonation, and killed a lot of engines, as i understand it. a slightly later 6CA points plate and AAU will drop right in, will allow you to put the condensors somewhere cooler, will let you time each cylinder individually, and will give you as good a points ignition as you can get. swap meets are good sources for points plates and matching AAU . look fir one that isnt worn out . many were replaced with EI specifically because they were crap, but there are some good used and NOS still out thrre
The good news is that my daily ride is now repaired, so work can restart on the T90. Just for fun, here is a pic of the blown head gasket, no clues.
Pulled the ignition coils out of the (shrinking) box of bits. The resistances on the primary coil (two outer connections) and the secondary (centre HT connection and an outer one) are similar to a working 12v coil. That’s close enough to start, i will put them on the bike and see how good they are when i get it running. Need to clean them first.
The carb that was on the bike is an Amal mk1 concentric 930/22. Spec as follows: 1 3/16 bore 928 2.5 slide needle with 3 ring marks / three grooves, clip in groove 1 150 main jet needle jet not removed pilot jet 20. The carb that SHOULD be on the bike is an Amal Monobloc 376/300 15/16 bore 376 / 3 slide needle type C / clip in groove 3 180 main jet .106 needle jet pilot jet 20. i’m surprised it even ran.
Although it doesn’t look much cleaner the galleries and internals have been washed and blown through with high pressure air.
