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Discussion Starter #21 (Edited)
Have some more updates, and questions...

Got the oil slinger tool in the mail yesterday afternoon, and took that apart. Looks to have been taken off a bunch of times before, but never with the correct tool. No tabs were engaged, and it didn't require an impact wrench to remove, just a little tap. Clutch and oil pump came off. Oil pump measures fine and appears to work well
Basket looks good, small gear behind the clutch (P/N 28231-312-020) has a chipped tooth.
KIMG0485.jpg
The larger gear that interfaces with it (P/N 28221-312-010) has a whole tooth missing.
KIMG0486.jpg
The rest of the case splitting process was fairly straight-forward, except this little guy. Photo isn't as good as I'd hoped, but the bolt between the two bearing surfaces is broken off. There was no bolt on the outside of the case, so I suspected this would be in here. Still a little disappointing to have to fish it out.
KIMG0526.jpg
Will have to go buy myself an easy-out kit I suppose

Everything else looks good, except the huge amount of aluminum particles I found splattered all over the sludge-covered walls.

Regarding the kick start mechanism
1) Should the kick start shaft (the one with all the springs and the pinion gear on it) wiggle at all when it's attached to the engine case? Mine has some play
2) Anybody have one or both of the above part numbers sitting on a back shelf somewhere that they'd like to sell?
Numbers are: 28221-312-010 and 28231-312-020 (I think)

In reference to the previous couple posts, here are the "after" photos from one area of clean up. I don't have any before pics, but there was a lot of excess metal in there. It's a small overall difference, but I have more time than money, so I'll take what I can get :)
KIMG0530.jpg KIMG0532.jpg

Looking forward to vapor blasting this weekend. Case halves soaked overnight in simple green and hot water, and then got scrubbed this morning with a bunch of dish soap. Still a bit grimey, but much better than before when they were completely brown.

Captb - I've seen from some of your previous posts that you feel the NOS Output shaft seals are better than modern reproduction ones. I found two seals on ebay listed as NOS, one for $20, and one for $100. Any thoughts? I don't have to spend a hundred bucks on that seal do I?

One last question
Is the correct length for the factory cylinder studs 274mm? All I could find in searching was 274mm x 8mm x 1.25 thread pitch
 

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there's usually some play in the kick shaft when the side cover is not installed.

from looking at your pics I'd be after a new clutch basket and crank sprocket. the straight gears of the SL are hard (read expensive) to come by...the CB/CL staggard geared ones can be used as well so long as you get the matched set (clutch basked and crank gears with spacer) they will be easier and cheaper to source...they also happen to run quieter.

also look at the kickstart idler gear...I ALWAYS rebush that gear when rebuilding an SL...they are the known achillies heal to the SL motor.

I think CaptB's approach is to shim the idler gear...
 

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I just happened to come across this thread. I just tore down the motor in the parts bike I have and I think everything in the bottom end is pretty good. These parts can be had pretty cheap as I really dont have a use for them. You can see some generic pics in my parts for sale thread, if you are still needing the gears and such.
 

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Discussion Starter #24
Wow, long break. Finally back to work on the bike.
The good news? Santa Claus was mighty generous this year, and he focused on SL350 parts, so even with the delays, hopefully the amount of setback is minimal.

Still haven't yet had time to get the vapor blasting done, because I've decided to disassemble the wheels, have the hubs vapor blasted at the same time, and do new spokes and (possibly) aluminum rims. We'll see. One of the things Santa brought was a pair of Tubeless TKC 80's. SUPER excited about those.

JohnnySQ, I've got the new pair of clutch gears (as well as a spacer from captb via ebay), but I sent you a PM on some other goodies. Still haven't decided if I'll end up using these, or swapping over to a staggered-gear clutch basket. Thanks for checking in.

Carb question:
- I have two CB 350 heads, and one set of SL350 carbs. Can I make these work, or do I need to go to VM28's or VM30's?? Would like to keep the SL carbs if possible, because they're in excellent condition. Or I could go to a correct SL350 head if I can find one.

Tried to remove, measure, and inspect the cylinder studs, but it was a no-go after a bit of trying, and I don't want to break them, so they'll stay in. I also grabbed some spare parts off my old parts bike before scrapping it (complete basket case, mostly junk) including a spare tank in the same color. In pretty bad condition, so I'm considering chopping it opened, burning out the creeme liner, and then doing body work and making a higher-capacity tank for long back-road exploration. Not for a while though. Other priorities.
 

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I have a mint 3k mile SL350 head I spent a lot of time cleaning up for my #2 engine but don't need since I'm running the VM30s, seats/guides/theads and the rest looks nice.
$35 + actual shipping, comes as pictured. K1/K2 kick start model small intake head.
Large PICS keep clicking on them.
 

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Did you find the CS seal, I think this is the ones I ordered, they're double seal type not much chance of ever leaking anytime soon.
91205-333-015 OIL SEAL $15.16
 

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Discussion Starter #27
Yup. One of the holiday goodies was a NOS CS Seal. Looks identical to the link you provided, but in NOS Honda wrapping.
Of course, the one I pulled out was also double-seal type: one from the rubber seal, another seal from the silicone goop :)

Cylinder head looks pretty good. Is that a heli-coil in one of the plug holes? right combustion chamber.
 

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Yup. One of the holiday goodies was a NOS CS Seal. Looks identical to the link you provided, but in NOS Honda wrapping.
Of course, the one I pulled out was also double-seal type: one from the rubber seal, another seal from the silicone goop :)

Cylinder head looks pretty good. Is that a heli-coil in one of the plug holes? right combustion chamber.
Yes I forgot I even did that one it's been a while, threads were so so when I got it so I did it to save the grief if got worse when doing jetting.
I did the head on the engine in my bike now with timeserts since jetting required pulling plugs a hundred times while hot.
 

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Discussion Starter #29 (Edited)
Okay, good to know. Once again, I learned something new. Never heard of timeserts before, but looks cool. Let me think on the cylinder head and run some numbers.

Back to the kickstart mechanism debate for a second.

Outobie, you mentioned that the CB350 staggered-gear clutch basket will work in the SLK2, and runs quieter. I like the sound of that, but would this also convert it so kick start is via the clutch, and it's no longer primary kick? I can't put together in my head how exactly the SL kicker would interface with the CB basket. Just lose the idler and have the kick gear ride on the inner-most of the two staggered gears? I prefer to keep the dirt bike feel, and I have a habit of kicking with the clutch pulled in from growing up in the dirt. For now, I have all the parts I need for the stock-style kickstart mechanism. But if it fails again in the future, might be conversion time.

Also, does the shim on the kick start idler solve the Achille's heel issue, or should I still pull things apart with relative frequency to assess?
If yes to the latter, please define "relative frequency."

(searched but couldn't find) Any pictures on here of bronze bush or needle bearings for the shift shaft? Sounds pretty cool, but might be beyond my budget this time around....

Captb: Is my needle bearing cam out of the orange SL in your photo?
 

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Okay, good to know. Once again, I learned something new. Never heard of timeserts before, but looks cool. Let me think on the cylinder head and run some numbers.

Back to the kickstart mechanism debate for a second.

Outobie, you mentioned that the CB350 staggered-gear clutch basket will work in the SLK2, and runs quieter. I like the sound of that, but would this also convert it so kick start is via the clutch, and it's no longer primary kick? I can't put together in my head how exactly the SL kicker would interface with the CB basket. Just lose the idler and have the kick gear ride on the inner-most of the two staggered gears? I prefer to keep the dirt bike feel, and I have a habit of kicking with the clutch pulled in from growing up in the dirt. For now, I have all the parts I need for the stock-style kickstart mechanism. But if it fails again in the future, might be conversion time.

Also, does the shim on the kick start idler solve the Achille's heel issue, or should I still pull things apart with relative frequency to assess?
If yes to the latter, please define "relative frequency."

(searched but couldn't find) Any pictures on here of bronze bush or needle bearings for the shift shaft? Sounds pretty cool, but might be beyond my budget this time around....

Captb: Is my needle bearing cam out of the orange SL in your photo?
I can't say about converting to CB/CL basket/gears but I'm sure it would run quieter.
I checked my idler gear with about 4k miles and no issue, part of the problem I think is people not engaging the kick start before kicking it, 2nd would be the wobble but with the shim it runs true, also some people don't tune them and jump up and down on the kick start a hundred times.

Yes that's the cam set up that was in my SL, it ran cool and quiet, pamco worked great with it, minimal cam end play is good with pamco ign.
 

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Discussion Starter #31
oh, cool. So is the only issue with it the fact that it's got some pitting on the lobes? anything else to be aware of with assembly?

Found a place in NH that says they can weld and regrind the cam for $120 plus a bit more for the lifters, as necessary. looking to do that soon, so hopefully it'll be good as new.
 

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oh, cool. So is the only issue with it the fact that it's got some pitting on the lobes? anything else to be aware of with assembly?

Found a place in NH that says they can weld and regrind the cam for $120 plus a bit more for the lifters, as necessary. looking to do that soon, so hopefully it'll be good as new.
It worked excellent, cam was pitted when I installed it and figured later I would get it redone maybe try a different grind, it ran cool and smooth, pulled great to near 11k rpm.
it was run with my current CB head, I never tried the fat cam with the SL head. But I did run a SL cam with my SL head 1st, then I switched to a skinny CB/CL cam with SL head and stock SL carbs and would never go back to the SL cam.
 

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Discussion Starter #34
Captb - great to hear. Thanks for your thoughts. I'm trying to figure out what the heck to do with the cam. Pay big bucks and extra shipping to go with megacycle or delta? or run it up to NH for a few days and see how it turns out. I want a good power band, stock pistons and springs, and no need to have it rip all the way to 18k. Still plenty more research to do.

Johnnysq - thanks! off to read my PM
 

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Captb - great to hear. Thanks for your thoughts. I'm trying to figure out what the heck to do with the cam. Pay big bucks and extra shipping to go with megacycle or delta? or run it up to NH for a few days and see how it turns out. I want a good power band, stock pistons and springs, and no need to have it rip all the way to 18k. Still plenty more research to do.

Johnnysq - thanks! off to read my PM
It pulled good I was happy with the stock grind for the street, I run highway gearing about 5800 rpm at 60 mph actual speed in 5th and acceleration was good even going thru the gears at 6k.
Don't forget to run zinc additive the flat tappet cams last longer.
 

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Discussion Starter #36 (Edited)
Okay, old valve train disassembled finally. Intake valves were a little rusty, but came free with some bicycle chain lube and a bit of tapping. Then they wouldn't come out due to deformation at the top. So when I get my new head ready to go, what does the Hondatwins universe think I should install? SCI valves, Schumann, NOS from ebay, or Kibblewhite (stock size)?? Anecdotal evidence as well as personal experience gladly accepted.

Also, stock-style guides, or bronze?
 

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Discussion Starter #37
Sorry for the lack of updates! Still working on things, but trying to get ahead a bit in school chores so I can spend a weekend vapor blasting. I have a huge exam this Saturday, but all day Sunday is going to be bike work. Also been working on some other projects in my whole-bike restoration thread HERE.

In case any other members are working on this engine and need some help, I took A TON of photos during disassembly. Shoot me a PM or ask here, and I'm happy to provide them.

That's about it for now. Been shopping for parts, and found a source for NOS inner and outer valve springs, but haven't pulled the trigger yet. Still deciding on the valves, but I'm leaning towards Kibblewhite / Schumann. Decided on Swaintech for piston coating (versus BoreTech, simply based on cost). Carbide bore is still up in the air. I can have a bore/hone done locally for $110, or bore/hone/carbide at BoreTech for $360....
 

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We used Swain Tech for my friends Suzuki GT500 piston skirts (had some extra piston/cyl clearance) they did a great job and only $22 a piston, ran quiet no issues.
 

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Discussion Starter #39
Cool, Thanks CaptB. Good to hear some feedback. I'm planning to do both skirts and domes, and I emailed with swaintech to ask a few questions. They replied that:

1) They don't have any reason to believe their coating is incompatible with a carbide-infused bore. I wasn't sure if having a harder bore would be rougher on the coatings and cause premature degradation. They say it shouldn't be a problem.

2) I wasn't sure what clearances to use for bore/hone. They said to run at the lower end of factory spec, or just below the lower end of factory spec. So the coated pistons like to be tight in the bore.
 

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Cool, Thanks CaptB. Good to hear some feedback. I'm planning to do both skirts and domes, and I emailed with swaintech to ask a few questions. They replied that:

1) They don't have any reason to believe their coating is incompatible with a carbide-infused bore. I wasn't sure if having a harder bore would be rougher on the coatings and cause premature degradation. They say it shouldn't be a problem.

2) I wasn't sure what clearances to use for bore/hone. They said to run at the lower end of factory spec, or just below the lower end of factory spec. So the coated pistons like to be tight in the bore.
The GT500 engine had been rebuilt but had piston slap, the coating was done on the heavy side and sanded to get it to a tight factory spec and new rings gapped to spec. With the hard to find 2 stroke cylinders saving doing extra bore jobs is a good thing when only one bore is left on them. Bore Tech can probably tell you how tight is safe on the skirts so you don't get a cold seize, if tight letting them warm up is good.
 
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