Honda-SOHC

Thanks Bryan

Turns out the measurement I was looking for is the diameter of the tubular section of the nipple that's the transition from immediately below the cap down to the squared/flat section(s).

Mine measured out at around 7mm, which translates to 0.275in.

Can't find a thumbs up emoji . . .

Thanks again.  Yip, that's what mine looks like.

On the subject of rivets, am I right in thinking I should be looking for drill screws to replace that kind of rivet with?  I've got a similar issue with the VIN plates, insofar as I'm not sure what type of rivet to use to replace the ones that have been drilled out (for frame powdercoating).  And any pointers on sources would be really helpful 'cos I can't find any that can be easily had in the UK.

How do all.

I have a somewhat peculiar question - were there any 750 models with lower yokes that came with steering locks that differ from the standard Honda removable lock barrel set-ups?  I have a feeling I already know the answer, but . . .

 . . . here's why.  My bike was a mongrel before I got it.  Whilst it hadn't been cut up, it had been <ahem> transformed into a very scruffy cafe racer.  Fortunately, nothing that was done to it couldn't be undone and over time I've returned it to pretty much what it should look like.  The forks and yokes are the ones that came with the bike and as far as I know, the top yoke is from a K2. 

The bike came with an ignition key and a seat key, but something I never really paid a lot of attention to was the steering lock, principally because it looks like it takes a much smaller key than the others, and that key was/is missing.  But now I think about it, nothing about the lock is the same as the Honda style; the keyhole is very much smaller than standard, the barrel is (so far as I can tell) fixed into the mount, the mount itself is oval when viewed from head on (as opposed to round) and the lock cover/flap is directly attached to the lock mount   
 
And that has led me to the conclusion that the lower yoke probably isn't from a K2, or maybe even from a Honda at all.  Annoyingly it's too dark and miserable - not to mention too strange an angle - to photograph right now, so rather than ask anyone to speculate on whether it's from another make altogether, I'll just repeat the question were there any 750 models with lower yokes that came with steering locks that differ from the standard Honda removable lock barrel set-ups? 

It's all a bit strange.  I'll try to get pictures up as soon as I can. 

I've removed locks with the use of brute force - more by accident than design - but it's not something I'd recommend.  The frame metalwork that holds the lock barrel in place is quite easy to bend and doesn't need to be bent far.  As you'll know, the pin that acts as the lock isn't very tall and all that needs to happen is for the metal mount to be bent far enough out to allow the assembly to be pulled past it.  Bending it back into shape is pretty straightforward . . . assuming you haven't snapped something important in the process.  I've learned since then that the best way is to check each lock for the key number and then find/buy the right key.  It's a hell of a lot easier that way. 

Having said that, my '750 K2 has a steering lock type that I've not seen on any other Honda of the period.  It takes a much smaller key (and one I don't have) than the usual locks and it has no number.  I've been meaning to ask here if it's right or not or whether anyone recognises it.  When I got the bike, it was a bit of a shed and I have no idea how much was still original.  The forks and yokes look right, but like I say the lock is . . . well . . . different.

Just thought I'd update something in this thread for the benefit of future generations . . .

 . . . Honda in the UK will now provide proof of year of manufacture for its bikes that were originally sold outside the UK.  I know 'cos they've just done one for me.  As long as they can trace the bike back to the factory it was assembled in, they'll supply a dating certificate.  Current charge is £30.

Looking at the e-mail address (certificateofconformity@honda-eu.com), I'm pretty sure those requests dealt with by the same department you need to contact if you want a certificate of conformity to apply for an exemption to the ULEZ in London.  From what I've heard, they'll only supply those certificates for bikes made after the year 2000 (roughly the same time much of their range became fuel injected).

Apologies for blundering in here but I've got a couple of suggestions that I don't think have been mentioned yet.  They're both a bit left field, but given how frustrating this can be, I thought I'd chuck them in for good measure . . .

 . . . first, I'll apologise for not being familiar with the Boyer kit, but when you say it comes with a rotor, is that a replacement for the spark advancer cam mechanism or is it the whole mechanism that's replaced?  I ask because if it's the former, you might want to check the springs on the spark advancer bob weights.  If one has lost some of its tension it'll flick out at inappropriate times - especially at idle - and you'll experience symptoms not dissimilar to those you're seeing.

The second is more dramatic and hopefully a very, very rare thing, but check then end the rotor is mounted to for deflection/out of round.  Get your guy to put a dial gauge on the crankshaft end, turn the engine over very slowly and check for round or play.  Again, if it's out you'll get some funny running and like I say, it's a bit out there . . . but it won't take five minutes to check when set up.

I can't take credit for any of this stuff.  I learned the first one the hard way over the course of about 8 years working on and off on a project - it drove me the same kind of nuts you're experiencing and no mechanic near to me could figure it out either.  Ultimately, Mark Paris (HondaMan on the US site) came to my rescue, and the crank suggestion came from reading his book.

Good luck.

Just had the registration documents through for two '66 bikes that have come in from overseas.  Followed the advice above and was able to supply title documents.  Was only able to send a set of photos for one, but the DVLA processed both applications without any questions.  They've also marked the bikes as being taxed (or whatever the historic equivalent is) until August next year.  One's nearing completion, but quite whether I'll have both on the road by then is another matter . . .

 . . . and if there's room here for a teeny tiny mumblebrag, I've been given a identical letter/consecutive number sequence (i.e. ---689D / ---690D).  Not all that much to get excited about, but I thought it was pretty cool . . .

It's been a while now since I did mine, but I've had different experiences when it comes to inspections.  I didn't send photos in with the first application, but did include dating cert, MOT and insurance cert.  Even so, the DVLA demanded to inspect that bike, despite it being a fairly common model.  This was at a time when the DVLA still had local offices, so I had to drag the bike down to them for a bloke to spend thirty seconds cross checking the frame and engine numbers.  Not an experience I wanted to repeat . . .

 . . . so with the next two, I sent the same documents with 4 colour images on one sheet of A4; the frame number, the engine number and one of each side (to give context and to confirm colour).  Same basic applications and documents - and no inspections needed on either of those. 

Things have changed since then; the DVLA no longer has local offices, and with the relaxing of the tax/MOT legislation for older vehicles, there's no money in it for them now.  Consequently, I suspect the DVLA want to spend as little time on applications like these as possible now, which is probably why Phil found the process so straightforward.   

For the bikes I'll need to register soon I have the title documents (that's a new one for me), so I'm hoping the process will be equally simple, but I'm still going to submit pictures in the same format as before, just to give the application that extra little shove in the right direction.