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Discussion Starter #1 (Edited)
So I started this project about 10 weeks ago. I have never fixed up a bike nor do I have my license. But decided what the hell. Thought that I'd finally start posting about it but it may take me a few posts to catch it all up. Picked up a Honda SL175 1972. Bike turned over but hadn't been started in 25 years or so. Someone somewhere along the way had taken off the exhaust system, and it was missing the left side air cover and the speedo case and mirrors but other than that was in pretty good nick. Had only done about 4500 miles!

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So I started by replacing the spark plugs and changing the oil. Put in a new battery. Cleaned out the fuel tank, and replaced the fuel lines. I put on some inline filters but they were terrible! Didn't let the fuel through. Try flipping them around as I thought maybe I had put them the wrong way around but no. Should have spent more money to get better ones. I will eventually put some on but this is a job for later on. The drain plug was really stuck on and I had to extend the wrench to get enough torque by attaching a 1.5m metal pole onto the end.

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It was at this point that someone pointed out to me that the front fender was on backwards. Weird. Anyway swapped it around.

I tried taking the right air cover off and it started cracking so that put me off. I ended up using some soft rubber on the end of a stick to push it from the other side. I took off the air filter body which had some perished foam still on it. I put some fuel in the tank and fired it up. Wouldn't really idle but I figured after 25 years that wasn't too bad.

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I ordered some air filters from UniFilter and currently have put the left side on. Still have to clean the right one.

I found a guy 30 minutes away who had two sets of exhaust pipes. They were in okay condition, some better than others. There were a few holes in the one that I wanted to use for the right side so I took it to a mate who welded on a new piece of steel. It's a bit of an eyesore but it's functional. Figure that I can replace it down the line or cover the pipe if need be.

Then came the search for a muffler. My neighbours were not enjoying me firing it up nor was my family as it is under the awning of the house so the noise reverberates a bit. All the ones I saw online were pretty rusted out and expensive, especially the postage as they all seemed to be in the US and I'm in Australia. I pondered it for a bit and decided that I'd buy a couple of megaphone mufflers and would rig it onto the bike somehow. Anyway they arrived in the post and I sat on them for a couple of days. Meanwhile on Facebook a guy was advertising wrecked Honda parts. He didn't mention SL175's but I thought I'd messaged him anyway thinking that I might get lucky with some parts. Amazingly he said that he had a muffler for an SL175! He also said that he had an air cover. No heat guard but hey I'm not going to complain.

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He was only a 20 minute drive away too which seemed way too fortunate. Yesterday I went and collected them both. The muffler is in really good condition. The air cover seems to have been painted at some point to be black but underneath it seems to be blue. I'm going to have to figure out how I can clean it up. I couldn't believe that it was the cover that I was actually missing! What are the odds? 50/50 I guess but anyway.

So that pretty much is where I'm up to. I've driven it forward about 1 metre to see if it works. Seemed fine. There are still a few things to do. Get a heat guard, put on some inline filters, sort out the air covers, there are a couple of small cracks on the frame that'll need to be welded, attach the muffler, clean up the bike... The metal could use a lot of elbow grease. I've started this process but it is taking ages...
 

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Discussion Starter #2 (Edited)
I thought that I'd post some more pictures of the bike
See the interesting new exhaust pipes...
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The fix is pretty obvious but hey no fumes seem to be coming out!

The air filters from Uni Filter

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The air cover which shows the blue coming through in some of the cracks. If anyone knows how I can take this off please let me know.

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And the front of the bike with the fender the right way around and the wrong way around.

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Sounds like you're coming along nicely. You might try the pictures again though, seems nothing came through.
 

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Discussion Starter #4
Sounds like you're coming along nicely. You might try the pictures again though, seems nothing came through.
Have given it another crack. Not sure why they weren't showing. They were on my computer. Can you l let me know if it worked?
 

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Discussion Starter #6
So there is an interesting problem that someone out there may be able to help me with. The electrics seems a bit weird. The switch has 3 positions: Off, Red and Green. The bike starts when it is on red? Also when it is going the back lights seem to constantly be on. Anyone have any ideas
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Position 1 (all the way to the left) is Off, position 2 is Run, position 3 is Park (taillight only for roadside breakdown). Can't recall the colors being present but it doesn't change the position functions. When you say "back lights", there should be nothing from the taillight when the key is in the Run position (second/middle position or Red if that's the case but your picture is shaded in red color so it's hard to tell) and the headlight is off at the switch. There are no running lights, just taillight and brake light. If the bulb is on when the key is on but the headlight switch on the right handlebar control is off, check one of the brake light switches, one might be on when it isn't supposed to be.
 

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Keep the pictures coming, it's a useful reference for me !
 

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Discussion Starter #9
Alright so I put the other air filter on. Started adjusting the carbs but got distracted with other issues and I'll have another crack next weekend I think.

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Still trying to figure out what I'm going to do with the filter covers. The black paint doesn't seem to be coming off the new one easily. Will have to put some thought into it.

Figured out the brake light!. I had replaced the brake lever with one I bought online and it's not an absolutely perfect match. It was sitting slightly off the contact so the light was coming on. I think that I may have another one that I can source that might be a better fit. Please don't judge me for the Ugg boots.

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I found some mirrors from a mate. He was going to use them for a CB250RS but I don't think that he completed the project. Anyway they look pretty good. Not original but look fairly similar. I don't recognise the logo. It says made in Japan. If anyone recognises it let me know.

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The next thing are the two cracks in the frame. I think that when the bike was transported to me the tie down was too rough on the back of the seat. I think that this made two cracks which need to be welded. I have started cleaning it up and am hopeful that a mate will weld it for me this Friday. Then I'll paint it.

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Tractor Ron,
Nice machine! It's in very good shape for as old as it is.
The mirrors appear to be after market mirrors that can be used either left or right by re-orienting the clamping band on the back of the mirror. This design reduces inventory and cost.
This may be obvious, before your mate welds the cracks in the frame, be certain to bent the frame loop back into its original position, inline with the frame above the air filters.
A local motorcycle club I belonged to back when that machine was new, held hare scramble races ( a 2 hour, closed course race through the woods with lots of mud) in the spring and the fall. One of the riders raced a machine just like yours, I mean just like yours, complete with street legal lighting. Why? Because he rode it on the highway (not a local guy) to get to the race and rode it home again after the race (usually with a trophy). He was one of those people with enough natural talent that he was competitive with the best riders, on the best machines in Western Pennsylvania.
Mark
 
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Discussion Starter #11
Realised that I haven't posted in a while. The carbs ended up being pretty clogged up. Pulled them apart and cleaned them out and it runs heaps better.
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Had a oil leak that I figured out was coming from out the tachometer cover. Wasn't sure if it was from the cable or the packing cover. The cable was pretty tired and distressed so got a replacement and that seems to have stopped the leak but I'll have to keep and eye on it.
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You can make out the weld on the frame in the next image.
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I probably need to source some paint to touch up some areas of the frame. So I can't seem to find a heat shield. I missed one on eBay and am kicking myself. So I've started to fabricate one. At the moment it is just a piece of metal in the rough shape but I hope to make it look like the second image. It may just be a stop gap measure until I can find one.

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I have to admit I'm struggling to find tyres that will fit and look good. If anyone has any suggestions I'm all ears. The original tyres are looking a bit worse for wear. The sizes are 3.0-19 and 3.5-18.
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Discussion Starter #12
Alright so have mostly finished the heat shield. Just need to put one more bolt in the top spot but have to decide if I'm going to risk trying to bend it or just leave it as is.

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Found some tyres. Have booked in to get them put on as I don't want to do it myself. Brand is Heidenau K43 with a 2.75-19 on the front and a 3.5-18 on the back. Front is a little smaller than the original tyres but the treat is very similar to the original pattern. I'll post some photos once they are on.
 

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Discussion Starter #13
Well it is up and running. Got it registered before Christmas and have been running it around for a while. Everything seems to be in order but there is always stuff to tinker with.

Have been thinking about changing the sprockets to increase it's top speed. Was thinking of changing it to the same arrangement as a cb or cl from same era. I'd lose some of the acceleration but I can deal with that. It looks like the cl175 had 17 teeth for the dront sprocket and 43 for the rear. There is a sprocket manufacturer in the next suburb so I'll head their in the next couple of days and see what the options are.
 
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