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If you sand them down, then you'll have a low spot that will allow the fork seal to leak. Mine looked much worse than that (and were disposed of). My '68 had what had to be the original fork seals in there with 66,000 miles on the odometer. When I drained the lowers, there was a bunch of water, oil and sand in there.
 

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Discussion Starter · #46 · (Edited)
Does anyone know if the front forks from a '72 CB450 would fit?

Edit: Answered my own question. Not likely without also changing out triple tree. Finding new fork tubes is proving to be more challenging than I thought. Might have to try some DIY fixes for those small spots and get them to hold me for a while until I can find a decent replacement/upgrade option.
 

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Actually, the lower triple (steering stem) is the same but the upper (top bridge) would need to match the later fork tubes. Since it's a CL and you have a drum brake on the front, you'd either want to look for a later CL front end like a K5 or K6 with the pinch-type top bridge, or convert your CL to a CB disc brake front end but that might require other changes
 

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Discussion Starter · #50 ·
Actually, the lower triple (steering stem) is the same but the upper (top bridge) would need to match the later fork tubes. Since it's a CL and you have a drum brake on the front, you'd either want to look for a later CL front end like a K5 or K6 with the pinch-type top bridge, or convert your CL to a CB disc brake front end but that might require other changes
Thanks ancientdad, good info! I spoke with 66Sprint yesterday and it sounds like Honda went through quite a few versions of the front end on these bikes, which makes it tough to find an exact match in good condition. I'd like to avoid the inevitable zipper effect when you start swapping out parts!
 

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Discussion Starter · #51 · (Edited)
I need some recommendations on carbs. I have the stock carbs, which would need a rebuild including a new flapper valve which looks melted (backfire?), but I wanted to upgrade. I was thinking the Mikuni VM32s were the way to go. I pickup up one, but missed on the other so I need to either switch directions now or find the second one (VM32-193 left idle screw).

What would you guys recommend? I will be riding at mostly higher elevation, over 6,500 ft.

I know the Mikunis can be a pain to tune. Is it worth it? Do they give better performance?

I do not have the stock air boxes or filters so will likely be using pods.
 

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It's hard, if not impossible, to improve on the engineering that Honda did when these bikes were new. The intake, including the air filters and the connector tube between them, was designed specifically for the stock CV carbs. Honda didn't just throw it together, it was designed and tested. When new, the bike performed flawlessly from idle to redline. With no modifications done to the engine, Mikunis will only carburate, just like any other - not improve the performance. Though it can be done, changing carbs usually entails a LOT of trial and error plug chops and changing jets, needles, needle jets and even air filters to get the same idle to redline performance and consistency in carburetion that Honda spent the time and money to create.
 

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Discussion Starter · #53 ·
Heard and understood. That said, finding stock air boxes, filters, side covers, etc. seems to be tough and if you do find ones in good condition, pricey. I will admit, I also really like the clean look without the air boxes and side covers (cafe racer style). What’s my best option? Can I make it run good with the VM32s? Should I look for a different carb?
 

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Mikunis are very simple carbs and fairly easy to tune. If you go with Mikunis be prepared to also buy a variety of jets and slides as you will most likely need to mix and match in order to get what you want. This can get expensive if you can't nail it right away.

400$ for fork tubes seems excessive but what do I know.
 

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If you're going aftermarket, Mikunis are the best plan and as Pete mentioned above, there are plenty of parts available to work with to get them properly sorted. However, as Pete also mentioned - and you should take this into consideration when you think that going back to stock would be expensive - you can spend a small fortune on Mikuni jets, jet needles and needle jets as well as slides to get them dialed in right, or you can live with the occasional flat spot in the rev range once you get them close. The last part - getting them close - is why I personally think finding good used parts to put it back to stock would probably be about the same cost in the end, and the stock parts would be foolproof, no excessive (if any) rejetting and plug chops to get things back to the way it was designed. Expensive new air filters? You buy old used ones for the frame and cut the old, dirty paper off the outside and use Unifoam instead.
 

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Once again, variations from the stock intake parts will have a big effect on overall carburetion throughout the rev range. Worse yet, if you're dead set on using pods, you may as well go with Mikunis as the factory CV carbs like them less and there are far fewer variations of jets, and no assortment of needles or position adjustments, for the stock carbs to compensate for the massive change of using pods.
 

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Discussion Starter · #58 ·
So I tracked down the long threaded rod that goes through the bottom mount on the frame and engine that I was missing. Now I have the issue that the hole in the frame is 10mm diameter and the bolt is 12mm! Did they go to a larger size in later models? I had a hard enough time finding this rod at a reasonable price that finding another, and potentially having the same issue, does not sound great. Would it be out of the question to carefully widen the holes in the frame to allow the larger rod? I'm not sure if the engine hole is 10mm or 12mm, I need to pull the engine out of the frame to see. Best I can tell this is not a structural point, but just another mount for the engine, but I'm also not an expert or an engineer!
 

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Discussion Starter · #59 ·
Does anyone know what the pitch on the threads for the rear swing arm pivot bolt and nut are? The threads on mine are a bit messed up and I can't get the nut on. I have tried cleaning them up with a little file, but I thought I might see if I can find a tap/die and clean them up properly. I believe they are 8mm just don't know the thread pitch.
 

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Discussion Starter · #60 ·
Picked up an old seat off eBay. It didn’t fit against the tank well so I tore it down and pieces together the old foam and reshaped it. Covered with some carpet padding. I know it’s probably not the “right” way, but it works for me! Now to find some brown leather or something to make a cover.
309020

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