Honda Twins banner

21 - 38 of 38 Posts

·
Registered
Joined
·
47 Posts
Discussion Starter #21
Thanks Tom,

I agree, think I'm after torque more than top end HP. But the other sounds pretty damned fun too.

The 120-00 looks like a good all-around option. With the 120-x11/x12 set, how did you feel it was compared to stock? Noticeable loss of low end torque?
 

·
Administrator
Joined
·
12,942 Posts
The 120-x11/x12 set ran nice, it was more of a broad increase and ran well at lower revs but I wouldn't say it improved torque, it was more like it didn't take away from the lower rev performance while adding to mid and top end power - but also, not a massive increase there either. For what they describe, I expected a bit more from them and you have to run higher compression pistons that are flycut for the additional valve clearance needed. Then you get into higher price for the pistons, around $500+ for a pair, as well as larger bore - most 3mm or 4mm over and custom made, as they don't have sets sitting on the shelves today for these engines as they once did. IMO, with your intended usage you should stick to a 1mm overbore and run the set of cams that work with stock pistons so you maximize reliability for the average rider (not a statement of your skill level, it's about simplicity of operation and maintenance). Once you venture into higher compression pistons with higher lift and longer duration cams, it gets harder to jet properly (you'll be using stock carbs assumedly, which will also limit your capability to re-jet them and limit the total performance increase you'll get) and it runs hotter so you can't just plunk around trail riding all the time or it will overheat and cause premature wear. I have around $2500 in my engine to get where it is now, and a lot of jetting effort with Mikuni carbs to get there too
 

·
Registered
Joined
·
47 Posts
Discussion Starter #23
@ancientdad, much appreciated info. Reliability is definitely a key factor for me.

Sounds like my plan will now be to stay with either the stock cams or upgrade to the 120-00.
With the 1mm bore, are any of the other non-wiseco options worth considering?
 

·
Administrator
Joined
·
12,942 Posts
Which non-Wiseco options are you referring to? Cleaning up the ports can be helpful and certainly wouldn't hurt on yours if you plan to go 1mm over and change cams, and matching the carb stubs with the intake ports as well. If there was a true electronic ignition setup out there with electronic advance that was proven reliable, that would be good as well... but as you can see by my signature, I'm not running one yet. There are a few that use the stock advancer and they work well but as long as the stock advancer is still involved you still have a mechanical device helping control an electronic ignition, though I suppose it's still better in the long run. A good AGM battery would help too, these engines need a strong battery to help them run best, and a Sparck Moto combo rectifier/regulator would be an upgrade you should do anyway regardless of ignition system you use.
 

·
Registered
Joined
·
47 Posts
Discussion Starter #25
@ancientdad mostly referring to pistons I’ve seen at Charlie’s Place (made by Wiseco?) and Common Motor, and then the cheaper sets on Dime City, eBay, etc? Or those NOS Honda “Rocky” pistons.
I don’t know much about pistons in generally so was just curious.
Thanks for the ignition/electrical advice. I’ve used a Ricks regulator/rectifier with a li-ion battery on my cb350F, in conjunction with the transistorized module. Was a definite improvement over the stock setup. I’d also ran all new wire so I’m sure that helped things a bit. I’ll give Spark Moto a look as well.
 

·
Registered
Joined
·
47 Posts
Discussion Starter #26 (Edited)
Update: First issue.

I had noticed earlier that the cast stop for the kick start spindle (lower case) was chipped.

Now that I've got it apart and a bit cleaned up, it appears that wasn't all the damage...

310225
310226


Time for new cases I guess :(
 

·
Registered
Joined
·
4,348 Posts
yeah well you've done the hard work already by splitting the cases.
Finding a replacement bottom shouldn't be too bad


Better ask to make sure this one is ok where the kick starter stop tab is though.
 

·
Premium Member
Joined
·
650 Posts
I agree with 76Twin, I think K1-K7 bottom cases are all the same. I’ve got a Honda parts manual for K1-K5 I will reference. Additionally I think I have a K3 bottom case I could let go of that is in better shape and will be cheaper than the EBay one. It would be a day or so before I can put my hands on it though.
 

·
Premium Member
Joined
·
650 Posts
Alright, so as I am posting this which is from an original factory parts manual CB450 K1-K5 I remember this thread is about a CL450. So I cross reference these part numbers with the CMSNL parts fiche and see the same part numbers apply to both models. The CL uses the earlier part number up through serial number 1009805 and the CB made the switch at 3004195. What does this mean? Ideally find an early K1 CB lower case or an actual CL K0 case. The chances of that? Pretty slim. Seeing as how it is only the classification number that is different it is most likely safe to assume it is only a small difference in some part of the case. Wouldn’t it be coincidental if the change was actually a beefed area around the kickstarter?
04BDD029-CEE5-4E3F-899A-878CED2CA7D4.jpeg
 

·
Registered
Joined
·
47 Posts
Discussion Starter #33 (Edited)
Thanks guys. I was excited to find another set of cases from a 68 K1 CL on eBay and luckily asked the owner to inspect. Evidently had a crack in the same location...

To clarify, its ok to mix/match Upper/lower cases? I wasn’t sure if they were machined as a pair or if that made a difference.
 

·
Premium Member
Joined
·
650 Posts
I do not have any evidence to back it up so this is merely my opinion, but I have never heard or read anything that leads me to believe the cases are machined as a pair. In the UPPER case there is a center bearing cap that holds the crank in place with 4 bolts. I believe that is matched to work with a specific upper case however.
In your instance here I believe you would be OK using any 5 speed bottom case.
 

·
Administrator
Joined
·
12,942 Posts
Actually, because the crankshafts are all roller bearing, the 4 bolt cap is universal as well AFAIK. Any 5 speed lower case of similar years (just to be safe based on the part number difference, despite it only being the last 3 digits which is usually not indicative of major changes but often simply other manufacturers, different colors, etc) should be just fine. Since the engine does not have any plain bearings on crank or rods, there is less concern for precision tolerances in case matching
 
21 - 38 of 38 Posts
Top