Topic: Keep telling yourself - a restored 750 K2 is an investment

[the-chauffeur]

Cool. All of the main bits are off the bike again and the new parts/stuff should be arriving tomorrow. And the tank and panels are in for painting - Christ, why couldn't Honda use the same shades of golden sunrise orange (or whatever it's called) on the 450 and 750?  Yeah, they're a couple of shades different. 

Moving swiftly back to the 450, I tried it again today to see if I'd missed anything, and when I tested the compression from cold, both cylinders registered the same (IRO 135-ish).  Still didn't get it to fire up, but that's probably gotten something to do with the, ahem, wrong spark plugs.  Don't ask me where I got them from, but I found that I'd been using BR8ES's rather than B8ES's, which would explain why it's sparking, but not powerfully enough to fire.  Muppet.

Anyways, after a rest, I tested the compression again and the right hand reading was 20 or so down.  Stuck some light oil in and tried again - readings were back to the previous levels.  Bearing in mind the cylinders, rings and pistons are all NOS, I'm wondering if the drop off has something to do with the rings not having bedded in - if the right hand carb is set rich, could it be that the unburned fuel is washing in and round the cylinder and draining down through the ring gaps?  If it ain't that, I'm struggling to know what else might be out . . .

 . . . phew . . .

[HondaMan]

Cool. All of the main bits are off the bike again and the new parts/stuff should be arriving tomorrow. And the tank and panels are in for painting - Christ, why couldn't Honda use the same shades of golden sunrise orange (or whatever it's called) on the 450 and 750?  Yeah, they're a couple of shades different. 

Moving swiftly back to the 450, I tried it again today to see if I'd missed anything, and when I tested the compression from cold, both cylinders registered the same (IRO 135-ish).  Still didn't get it to fire up, but that's probably gotten something to do with the, ahem, wrong spark plugs.  Don't ask me where I got them from, but I found that I'd been using BR8ES's rather than B8ES's, which would explain why it's sparking, but not powerfully enough to fire.  Muppet.

Anyways, after a rest, I tested the compression again and the right hand reading was 20 or so down.  Stuck some light oil in and tried again - readings were back to the previous levels.  Bearing in mind the cylinders, rings and pistons are all NOS, I'm wondering if the drop off has something to do with the rings not having bedded in - if the right hand carb is set rich, could it be that the unburned fuel is washing in and round the cylinder and draining down through the ring gaps?  If it ain't that, I'm struggling to know what else might be out . . .

 . . . phew . . .

Yep, the 2 different factories had a lot to do with those "almost the same, but not" colors. The 750 really suffered from this, because it was built in two different factories from the late K1 onward, and having two gold bikes on the showroom floor, one from each factory, really showed it up. The newer factory did a much better job of laying the paint, making nicer looking bikes.

That 450: it's not unusual for the right cylinder to be lower, until the rings are well seated. This can take 2000 miles or more. Also, with that bore (Honda's biggest, at the time), if the bike sits a long time, then gets run just a little, the right cylinder's compression would always drop a little, then come back after a few hundred miles. The 350 twin did this, too.

[the-chauffeur]

Thanks again HM - another 450 question a bit lower down, but in the meantime - and fingers crossed that all the leaks are cured ( . . . I've still got to start it up again to check) . . . here's the 750 . . .

 . . . and a few more . . .

,,

Don't even think about asking how much the paint, transfers and badges on the tank/panels cost, although it was well worth it.  The guys who painted the bits lacquered the tank stripes and helmet warning sticker on, then flatted the lacquer, then re-lacquered, then repeated so that the whole thing is completely smooth - top work.  I reckon that's the 750 pretty much finished for now (again, he says).  OK, so there are some minor bits around the edges that need a bit of tidying - I've got a NOS front mudguard with holes for a front numberplate that needs fitting, and I really could do with a decent set of clocks, but there's no hurry for those.  Now it's time to get some miles on the ol' girl.

Back to the 450.  I think the problem I've got is engine timing.  It might be 180/360 deg out - or some other fraction for that matter.  The big problem I've got is that the timing mark on the exhaust cam isn't there.  I dunno whether it's worn away (seems unlikely) but it's so faint that it pretty much can't be seen.  So today's question is how do you work out where the timing mark should be on a DOHC exhaust camshaft without one?  Ideally, I'd have another ex- camshaft to compare it to, but I don't - they're a bit hard to come by over here (UK) - so I'd like to see if I can work out where it should be on my one.  But if it's not possible/very difficult, I guess I can always get used one from eBay US and just compare the two.

Regards

Neil

[HondaMan]

Beautiful work, Chauf!

[tworiversuk]

well done buddy that is a credit to you persistence