Been putting more miles on the bike since the engine rebuild. Rode around all Saturday, along Route 66 and halfway up Mount Baldy before I froze my ass and my knuckles off - 80 miles that day.
The bike can be better. With this much time and attention I put in so far, it deserves to be something more than it currently is.
These are the issues so far that bug the heck out of me (aside from some of the cosmetics like the seat and tank):
- 1st gear is not engaging correctly
- Blow-by
- Lean symptoms despite rich settings
- Oil leak at cylinder head cover
1st gear does this thing where it intermittently engages/disengages when going from idle to about 1/4” throttle. That’s really the best way that I can explain this beyond the egregious sound that it makes, “ka-chunk-rattle-rattle-ka-chunk...” When this happens the bike stutters and I’ve trained myself to then pull in the clutch and quickly shift up to 2nd. I should really just start on 2nd.
I’m tempted to drain the oil and drop the pan to find that there are teeth knocked out or some gear bits but I’m still working out some other issues while this break-in oil is stewing...
The blow-by issue is dumb because this can be the result of a few things. When honing the cylinders, there were some pretty deep gouges in the sleeves, as though there was some ring damage. I was fooling myself thinking I could try and hone those out.
Another possible contributor of the blow-by is the valve stem seals are shot; but these were recently replaced for new ones. I can’t see how those can go on a wrong way but I’m not saying that impossible either. And then there are the valves themselves which I lapped fairly well. I imagine those would be settled by now. None of them were bent in any way that I could see. Whatever the case may be, the blow-by hasn’t lessened. I have a container strapped to catch the vapor and any oil from the breather
And this may be only a portion of it since I didn’t have this catch container mounted until fairly recent. Normal? Excessive?
My spark plugs are looking real lean despite the following carb set up:
88 Main Jet (aftermarket purchase from 4into1.com)
40 Slow Jet
5th needle groove from top (last slot on the bottom)
1.5 turns out on air/fuel mix screws
As you know, I have air pod filters and an aftermarket exhaust (Outex).
I figured a raise in the needles - I had previously set them 4th groove from top and got lean results - would make for a richer condition but I’m getting the same lean result. Then, I was reminded of this chart:
NEEDLE TAPER. The needles I have in now are stock Keihin, the point of which is attempting to work with an aftermarket 88 main jet. TwoTired has mentioned something about this before where it was critical to get a correct needle taper profile and usually a bad idea to mix and match brands. These jets ordered from 4into1 might be different in shape and profile so maybe not a good fit; certainly not Keihin quality. But, perhaps they work well with their own brand? Luckily, I have a set of these needles from another 400F rebuild that ended up keeping the stock needles which obviously worked well. In any regard, referencing the chart above, needle taper does account for a bulk of the carb’s functionality. I’ll install these aftermarket needles to fit into the aftermarket 88 main jets to see how that goes. Will keep y’all posted.
This is all quite a setback. I’m tempted to replace the engine parts from the cylinder on up. I’m on the fence about overbore. I imagine there’s still a good likely hood of blow-by with that also...
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