Nixon, 1972 Honda CL450 Scrambler Refurb

Flugtechnik

My bike is not transportation, it is a respite
Most of you who have been on here awhile have seen this before. She's been around the block. It's time for another rebuild, the final rebuild.

When I bought her, she looked like this.



Then I did the cafe thing. Custom aluminum tank and seat. She looked like this until I rode her off the side of a mountain.
http://www.dotheton.com/forum/index.php?topic=9560.0




Ooooops.
http://www.dotheton.com/forum/index.php?topic=36724.0




Then we (with the collective help of DTT at the Barber Vintage Fest) rebuilt her into the scrambler she was meant to be.
http://www.dotheton.com/forum/index.php?topic=36857.0



Ended up pretty damn close to my design sketch.




Now, she is burning oil and popping out of 2nd gear. It is time for a final rebuild.

My progress will be documented below.

I don't plan on any major design changes. I'm just going to make everything right and "final".

Let's do it right this time around.
 

NoRiders

Active Member
Re: Nixon, A 1972 Honda CL450 Scrambler

The life and times of a CL.... ;D to be con't......love it.


PS Wipe out looked pretty serious man....how were you rebuilt?
 

Flugtechnik

My bike is not transportation, it is a respite
Re: Nixon, A 1972 Honda CL450 Scrambler

The first step in the rebuild will be to get the engine mechanically sound again. It is burning oil and I suspect the valve guides/seals are failing. I rebuilt the top end about 5 years ago, but it was my first time messing around in an engine so who knows what I did. It has also been popping out of 2nd gear, so I will be rebuilding the bottom end this time too. The last time I rode it, oil was gushing out of it when I got home. Let's see what the problem is.

First take off the pretty stuff.






Then pop the engine out with a rubber mallet.




Let's get to work....




Found the problem. The clutch pushrod oil seal popped out. The new one will get installed with some loctite.

 

Green199

New Member
DTT BOTM WINNER
Re: Nixon, A 1972 Honda CL450 Scrambler

Will Loctite be sufficient to secure the new seal from any increase in crankcase pressure?

I've seen some quite simple oil seal 'retainer' designs which are effective and secure using the fastener which holds down the stator wires.
 

Flugtechnik

My bike is not transportation, it is a respite
Re: Nixon, A 1972 Honda CL450 Scrambler

NoRiders said:
PS Wipe out looked pretty serious man....how were you rebuilt?
Luckily bones heal all by themselves!


Green199 said:
Will Loctite be sufficient to secure the new seal from any increase in crankcase pressure?
I've seen some quite simple oil seal 'retainer' designs which are effective and secure using the fastener which holds down the stator wires.
I think it will be enough. The seal doesn't fit very tightly. The friction of the rod might have actually pulled it out. The crankcase is vented with a sizable tube so pressure buildup should be minimal. If it happens again I will add a retainer as you suggested.
 

NoRiders

Active Member
Re: Nixon, A 1972 Honda CL450 Scrambler

A twisted wheel spoke (or wire coat hanger) could work as a seal retainer, maybe a ? shape?
 

Flugtechnik

My bike is not transportation, it is a respite
Re: Nixon, A 1972 Honda CL450 Scrambler

I spent last night taking the top end apart. First I had to remove the ignition. This turned out to be much harder than planned. I have one of PAMCO's original electronic ignitions installed, the one without the electronic advance.




It turns out that all of the movement of the advance mechanism caused the little nubs of the advance weights to deform the aluminum of the timing rotor. It was originally just a straight slot. I have only put MAYBE 2000 miles on this ignition. Looks like you should have used a harder material Pete! Because there is a small lip on the shaft of the advancer, the deformed rotor would not come off. I had to pry it off. You can kind of see where the aluminum scraped on the shaft. I was planning to get a new ignition for it anyway. I don't like all of the exposed electronics of the PAMCO and on this particular model, you can't adjust the two pickups separately.




Once I got that off, I could disassemble the rest.




Bag and tag...... Bag and tag......



 

irk miller

You've been mostly-dead all day.
DTT BOTM WINNER
Re: Nixon, A 1972 Honda CL450 Scrambler

Uh oh. ;)

I guess we'll have to get the misfits together on some weekends.
 

xulf13

West of Tennessee
Re: Nixon, A 1972 Honda CL450 Scrambler

Well Mike, you know I'm in. Holler if you need any help or moral support


Sent from my iPhone using Tapatalk
 

Mr.E

Got to keep the loonies on the path...
Re: Nixon, A 1972 Honda CL450 Scrambler

Uh Oh. see you are WAY more organized than I am. Lemme know if you need any help man, I'm not too far away and hopefully have less on the table in a couple weeks
 

irk miller

You've been mostly-dead all day.
DTT BOTM WINNER
Re: Nixon, A 1972 Honda CL450 Scrambler

Mr.E said:
... and hopefully have less on the table in a couple weeks
Yeah right. Good luck with that. ;D ;D ;D
 

whynot

~~~If it ain't raining, I'm riding~~{iii}?~~prost~
Re: Nixon, A 1972 Honda CL450 Scrambler

I'm in too.........

Cool build.
 

xulf13

West of Tennessee
Nixon, A 1972 Honda CL450 Scrambler

Where you at Mike? It's been 4 days already and I need my CB450 picture fix!


Sent from my iPhone using Tapatalk
 

Flugtechnik

My bike is not transportation, it is a respite
Re: Nixon, A 1972 Honda CL450 Scrambler

Thanks for the support guys!

I've been working out of town this week. I'll be back to wrenching tonight.

In the meantime, while I was disassembling the top end, I also took my carbs apart. I will be taking them to a local shop to get cleaned and they will also get refreshed with some new parts.




Interestingly, I found that the two carbs had different needles in them. Not only is the top different, but they have different profiles. When I bought the bike, it had two different sized jets in each carb, 130 in one and 145 in the other. I put 135s in both, but didn't realize the needles were different. Maybe this is why I could never really get it to run well. I was thinking about just throwing some mikunis on, but I will give these turds one more shot. Hopefully getting the same parts in both carbs will help them run better.

 

xulf13

West of Tennessee
Re: Nixon, A 1972 Honda CL450 Scrambler

Mike, I have a box with at least 4 pairs of these CB450 carbs. if you need anything just let me know and I'll mail you what you need or the whole box.
I too had the same issue with my carbs, different size main jets on each carb, never stopped to look if both needles were the same or not though.


Sent from my iPhone using Tapatalk
 
Top Bottom