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1971 SL350 K1
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Discussion Starter #81
I looked at my extra crankshaft today and I see that it isn't hollow but the bolt hole goes through to the other side so I got the threads cleaned good and I believe it will be ok. Since the weather is getting better I decided to set the carbs on the bikeand now it's ready for a test ride when I can get it out of the driveway without going through the snow. I saw someone riding today so I know that 40° is warm enough. Also started on the rear wheel project. I will need to fabricate a mount for the brake cable since it wss broken off in one of several crashes that the bike has survived.
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1971 SL350 K1
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Discussion Starter #82
I took the bike for a test ride today. Enough snow melted to get out of the driveway. 45° and sunny. I didn't go far just about 2 miles. It's running ok but I didn't re jet the carbs . They are set up for the other motor with lg. bore , more cam and high compression. Also 32mm carbs are a bit much for the stock motor I believe. My main concern is the shifting. It shifted very well. Before the tear down third gear didn't work. The other motor had third gear but shifted very hard. This stock motor was assembled with used gaskets and seals. Also old pistons , rings and cylinders. The head wss not checked. I'm not seeing any oil leaks yet. It doesn't make any suspicious noise. So far not bad for a quick throw together motor. Soon I'll have the other motor done and this one will go back into storage where it has been for the last 20 years.
 

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1971 SL350 K1
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Discussion Starter #84
Good morning. I thought I would work on the wheel today. I cleaned up the spokes and I will re use them. The hub was a mess and will take some effort. The new rim was never used but after sitting for decades it needed a good polishing. Maybe sometime soon I'll be mounting it and think up something for the brake cable.
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Discussion Starter #86
It's been a while. I'm back at it. The bike sometimes takes too long and work takes over. If it weren't for all my work hours I could probably find time to go riding . My trigger for the probe ignition came loose and the timing slot that aligns on the pin on the cam was worn. I thought I could re-tighten it and time accordingly. It didn't seem to run well and I couldn't get it to fire correctly. I don't know if parts or support for this system can be found anymore. I had 32mm Mikunis on the stock motor and they were tuned for the race motor. I didn't want to change them much so I got a set of 28mm Mikunis and installed them thinking that they would be better on the stock engine since it originally had 24mm carbs. Also I had a set of NOS points and mounting plate with NOS condensers so I installed them. The bike seems to run much better now. Idle is perfect at 1500. Seems to run great to 5000 then breaks up. I've re checked the points and set them at .012 then re-set the timing. Also charged the battery. I'm going for a test ride directly and I hope it runs better than before. Also compression is dead on 170 for each cylinder and valves are set a little loose at .006 for intake and exhaust.
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1971 SL350 K1
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Discussion Starter #87
A little better than before. Still some issues. At full operating temp the idle has increased to 2000 and seems a bit lean. Riding was better running through the gears it seems good shifting at 5000. Up to WOT at the lower rpm didn't break up but also seems a little lean. Breaking up around 7000 at 3/4 and WOT. I didn't try for over 7000 as with the stock engine put together with all old parts I'll never run it over 6000 anyway. Now I'll see what the plugs look like and go from there.
 

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Discussion Starter #88
Got some new plugs for idle test. I cleaned up the old plugs to warm up the bike and when I pulled them to put in the new ones they looked a little rich from riding. The bike wanted to stall coming off idle. Seems lean to me at idle. After the first plug chop at idle they looked lean. Screws were set at 1 3/4 turns out. Second pair were set at 1 turn out. They looked a but richer but the left one looks a little leaner than the right one. Although they are looking better I think I'll try a size larger jet .
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It's been a while. I'm back at it. The bike sometimes takes too long and work takes over. If it weren't for all my work hours I could probably find time to go riding . My trigger for the probe ignition came loose and the timing slot that aligns on the pin on the cam was worn. I thought I could re-tighten it and time accordingly. It didn't seem to run well and I couldn't get it to fire correctly. I don't know if parts or support for this system can be found anymore. I had 32mm Mikunis on the stock motor and they were tuned for the race motor. I didn't want to change them much so I got a set of 28mm Mikunis and installed them thinking that they would be better on the stock engine since it originally had 24mm carbs. Also I had a set of NOS points and mounting plate with NOS condensers so I installed them. The bike seems to run much better now. Idle is perfect at 1500. Seems to run great to 5000 then breaks up. I've re checked the points and set them at .012 then re-set the timing. Also charged the battery. I'm going for a test ride directly and I hope it runs better than before. Also compression is dead on 170 for each cylinder and valves are set a little loose at .006 for intake and exhaust. View attachment 314832 View attachment 314833
Hello Frank, nice photos, looks great. I did spot something in photo of points assembly. The end of intake rocker shaft has correct install with the hashmark pointing to 2 oclock position. (2 to 4 is normal). However the exhaust rocker hashmark is also pointing to a 2 oclock position, which is not correct. Left exhaust shaft hashmark should be between 8 oclock and 10 oclock. Both hashmarks should point outward, away from spark plug. The clearance can be correct but the valve timing is changed when the excentric is shifted from outward to inward. Its a common mistake, also occurs on CB450s. Moves the rocker and changes valve timing. All 4 rocker shaft hash marks point outward, away from spark plug. My early twins, 350, 450, CL77, all use OE Genuine Honda points, and I've always had good service from the OE Honda parts. Good Luck. John
 

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1971 SL350 K1
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Discussion Starter #90
Thanks John. I knew the adjustment worked in both directions but never thought about how it would affect the cam timing. I will reset the rockers when I get a chance. I've got a good selection of jets for the carbs but the numbers are so small that I can't read them under a magnifying glass. That makes things more difficult. I'll be changing them in a few days and get the rockers. I'll do a couple more plug chops and get the idle set then move on. I think when I get the carbs jetted the motor will run good.
 

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1971 SL350 K1
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Discussion Starter #91
I disassembled the carbs today. They had 25 pilot jets. I switched to 30 . I left them at 1 turn out and took a warm up ride. Then did a plug chop idling for 3 minutes. This is the result. Idle looks richer but still a little leaner on the left. I believe I'll need to double check the synchronization of the carbs then maybe the idle mix will look more equal. Idle is also lightly fluctuating. The warm up plugs look significantly richer to me. 145 mains. Will the idle mix carry into the mid range that much. ?
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Discussion Starter #92
I re-set the valves today. .004 on intake and. 005 on exhaust. Also set the hash marks to the correct positions. Re-set the points from. 012 to .014 and re-set the timing. It seems to idle about the same. No noticeable change. I went for a ride on the warm up plugs and the right side looked a little rich. The left side looked a lot rich. The motor ran well on low rpms up to 5000 then break up occurred. Still wanting to stall coming off idle. Seems to me that should need more fuel. With the plugs showing rich I decided to set the jet needles to the second position from the top which is 1 step leaner. It seemed to idle better but faster. Ran good to just over 5000 then breakup. Went from there to WOT and it ran better. Intermittent breakup but when it was firing good it was making power. Before the jet needle change it wouldn't take WOT. The plug reading this time ( iner plugs ) look leaner to me . The left side looks close to being good to me but the right side looks richer. Right side keeps looking rich for some reason. Everything is set equal. My thinking at this point is vacuum leak. I don't think tuning the carbs differently is the thing to do. Especially before exhausting all possible variables. Any thoughts, anyone. ?
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Check the voltage at the coils with the engine running at idle and at higher rpm's. It should be close to battery voltage at all times. I got caught chasing the same issue and it turned out to be a voltage issue.

On that CB there were issues at the key switch, kill switch, wiring in the headlight and ultimately a partially broken wire going from the headlight bucket to the coils.
 

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Discussion Starter #94
Thanks Boomer. I will look at the voltage and wiring this afternoon. I want to re make the wiring harness. This is new but I want to make some changes and it will be a good opportunity to check all connections. It has NOS stator, Ricks voltage regulator and a new battery. I will take a closer look to ensure that all is working properly.
 
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