1. OK, had my wires crossed on that one for sure. It was months ago now. The play was only side to side (less than 1mm or so at top of the rod, if I recall) on the rod. I remember reading widely about side to side play at the time and being relieved that it was the case with my con rod.
2. It doesn't feel like a back brake dragging when it does it. But maybe a back brake stomped on at random moments? Does that make sense? More of shuddering and hesitation through the rev range, gradually getting worse.
3. The guys on that forum say a washer and liquid metal would do the trick to block that hole. Apparently originally it would have had a plug in it as per construction but it seems maybe over time it comes loose. I'm going to do this ASAP because all other things considered, and like I've said, it runs pretty great until this problem happens.
4. Roger that. I'll put that in the brain bank. Thanks Buls!
5. It was a tad rich on 4 so I'll put it on 3. I can see daylight through both the jets. No apparent obstructions there. Will spray some carb cleaner around and blow it out anyway, along with the float bowl. Do I need to remove floats for cleaning? I'll start with chemicals and air. All else fails, wire it is!
6. I will see how it runs after this carb fix and take it from there. If the problem persists I will take the head off and have a look down the bore. If I see scuff marks then it is rings off to check ring end gap. If that's not it I will have a mental breakdown.
Nah, I'll go bottom end then. Though I think this might be close with this carb problem. Perhaps even if this carb thing works I will look down the barrel just to get certainty.
I can't thank you guys enough so far. Update to come in the next few days! I've been here before and I can say I'm optimistic but incredibly cautious too.
Originally Posted by buls4evr
1. You should have side to side play (horizontal), but none vertical on the rod. No up/down play if you hold down on the crank with your other hand. You should have NO crank play vertically or horizontally.
2. An engine can partially seize and not lock all the way up solid if you catch it fast enough. Early Bultaco Astro owners know this feeling well
. You get pretty sensitive to how this feels....sort of like running with a back brake on. Is that your feel?
3. That choke issue could introduce air into the mixture and will increase with venturi effect considering where it is. Question is, can you get another one?
4. If the exhaust were your only problem then the bike would run badly hot or cold.
5. The problem is not the needle. Put in pos 3. Check all your jet #s to make sure they are to factory spec. That bike ran great in 1965 and probably with those jets. Are they clean? Can you see daylight through them?They tell you not to do this but flip a wire brush over and run the jets through with a bristle of the brush. You may get crud out of them.
6. The top end removal is the only way to tell if it is seizing. Light emery cloth on any scuff marks, re-oil the bore. Check ring end gap or re-ring and put it back together again.