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Discussion Starter · #1 ·
Hello to Honda Twins.

I just purchased a 1975 Honda CL360, which I am very excited about riding and working on. This will be my introduction to vintage motorcycle maintenance; I am looking forward to the journey.

While I am quite mechanically minded, my experience in motorcycle maintenance in general is quite limited (I've cleaned out a carburetor and such, but that is about the extent of it). I'll probably be asking some very basic questions here in forum as I start to learn how to take care of this beautiful bike.

The motorcycle in is fairly good shape, and is completely rideable. I rode about 40 miles to bring her home, and while some tuning is needed I didn't notice any really major problems. Before riding again I'll make sure to do at least some basic care.

My first question to the forum is: What type of maintenance do I need to do before riding in order to ensure that I don't do any damage when I start riding more frequently?

The previous owner purchased from a dealer in 2011 with 9000 miles, and claims to have done careful maintenance over the last three years while riding an additional 3000 miles. Nonetheless I plan to start with all the basic maintenance as though it hadn't been done.

My initial list is:
1. Clean the oil filter and centrifuge.
2. Change the oil.
3. Adjust the drive chain tension.
4. Lubricate drive chain.
5. Adjust the cam chain tension.

I know I eventually need to pull out the carburetors and replace the intake manifolds as the rubber is starting to develop some cracks. I also probably need to adjust the ignition timing and carburetor synchronization since there is a flat spot in the acceleration around 4000rpm.

I did find this list on here: Basic Checklist for that New to You old Bike. Which I will work through eventually.


10615416_947686785259240_1560448702622779472_n.jpg

Amicitas
Princeton (Griggstown), NJ
 

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Welcome to the forum. Nice looking cl.
 

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Discussion Starter · #3 ·
I started work on her last night. So far everything is looking pretty good; this bike appears to have been well maintained.

I did a much more thorough inspection and got the drive chain tension adjusted, as well as the rear break. Air filter looks new, though they probably need a good dusting as soon as I have a chance to remove the exhaust system. I wanted to adjust the clutch and the cam tensioner, but I think I need to order some gaskets first so that when I pull the exhaust and generator cover I can get them back on without issue. Finally I went in to change the oil, but could not get the plug out . . . I just bought a breaker bar, and will try again tonight.

As of today I am also fully registered, so hopefully I can start riding tomorrow if I can get the oil change done. (The oil looks pretty clean at this point, but I want to change it anyway.)

If the oil comes out looking good, then I think I am going to wait on cleaning the oil filter and screen. I want to ride a bit before it gets cold, and I get the feeling that once I start pulling apart the engine, there is potential for me to get stuck for a little while.
 

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Unless there has been engine damage the centrifugal filter doesn't need looking at too often.
I've always found the clutch springs to be weak on Honda's, good 360 will get clutch slip at higher rpm so I fit CB350 heavy duty 'race' clutch springs from Bore-Tec
 

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If the oil drain plug is stuck, get a quality 6 point socket or wrench before putting a lot of torque on it. A six point has a lot more surface to engage the plug than a 12 point.
 

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If the oil drain plug is stuck, get a quality 6 point socket or wrench before putting a lot of torque on it. A six point has a lot more surface to engage the plug than a 12 point.
+1 on the 6 point socket. If possible ONLY use 6 point sockets as they don't tend to chew up bolt heads like 12 points do. The 6 point have more surface to surface contact with the bolt heads.
 

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Finally I went in to change the oil, but could not get the plug out . . . I just bought a breaker bar, and will try again tonight.
Hi amicitas, would like to hear your experience regarding the oil drain bolt. What worked and what didn't etc..

Thanks

Uday
 

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Discussion Starter · #8 ·
Uday,

I went out and bought a 1/2" socket breaker bar with a 12 point socket; came right out without any issues. The extra leverage was all I needed. I'm planning on slowly building up my tool kit as I keep working on this project, the right tools really do help. (A 6 point was not available at the hardware store, though I have since then invested in a proper 6 point wrench set.)

The oil came out in decent shape. It was dark, but only as I would expect and I did not notice any particulate matter. I have been riding around since, and very much enjoying this bike. At this point I have put about 200 miles on her. The flat throttle at 4000 rpm seems to be getting worse however. Now I often need to gear down so I can get up to 6000 rpm before I get the high end power. Even then it takes some waiting sometimes before the power kicks in. Seems like hitting a bump helps as well. Something is definitely sticky . . .

Amicitas
 

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Uday,

I'm planning on slowly building up my tool kit as I keep working on this project, the right tools really do help.

I have been riding around since, and very much enjoying this bike.
It is cool that you were able to get the oil plug issue sorted out. I am starting to gather an assortment of tools too. By the way, you have a beautiful motorcycle. Enjoy it.

Best regards
Uday
 

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Discussion Starter · #10 · (Edited)
This weekend I started the process of doing the full tune up that my motorcycle needs. I took the seat and gas tank off for easier maintenance (I wanted to replace the fuel equalizing line anyway), and pulled off the generator cover, breaker point cover, spark plugs and tappet covers.
IMG_20141115_131010.jpg

Compression test:
This test was done cold (and I mean cold, it's been just above freezing in the day, and below at night). Test was done with the throttle fully open (choke did not have a significant effect). I did about 10-15 kicks to be sure that I reached the max compression reading. Tube length was about 18".
Left: 145-150
Right: 155-160​
This looks fairly reasonable to me, though I might be able to tune the left cylinder a bit. I checked the left inlet tappet valve clearance and found that it was slightly too big (0.003" instead of the 0.002" spec. I wan't to check the rest of the tappets before doing any adjustment. (This is my first time checking tappet clearances, so I am trying to go slow and make sure I understand what I am doing here.))

Spark plugs:
The left spark plug looks pretty good, but the right plug is completely blackened with soot. Since I already know that there is some type of carb issue, and possibly a choke issue, it seems best that I work on cleaning out the carburetors and air filters, replace the plugs, and then see if the problem persists.
IMG_20141116_164328.jpg

Next steps for me:
Check and adjust all tappet valve clearances.
Check (and if needed adjust) the breaker point gaps and timing.
Pull the carbs and do a thorough cleaning.

Other thoughts:
When I pulled the breaker point cover, I found that one of the two bolt holes was totally stripped. What is the best way to handle this situation?

-- Amicitas
 

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Discussion Starter · #11 ·
I finished adjust the tappet clearances, which were out of spec. I also with checked the point gaps and static timing, which looked perfect to me.

Over the Thanksgiving break I started on a carb rebuild. When I got the carbs off and disassembled, I found some significant tears in both of my carburetor diaphragms. Looks like they will need to be replaced. This is probably the explanation for why I was having worsening performance issues.

Now I just hope I can get everything together again after dipping and cleaning.

I'll add some pictures of the carb disassembly soon.
 

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Discussion Starter · #13 ·
Finished with initial tune up

I have now finished putting everything back together and completing the initial tune up. Carbs have been completely disassembled, cleaned and reassembled with new diaphragms from JBM. I did a full vacuum synchronization, along with tuning the idle on both carbs.

I also finished going through the entire tune up list and adjusting everything as needed. As part of this process I have replaced lots of small parts (bulbs, brake light switch, gaskets, rubber pieces, fuel lines, etc.). For anyone interested here is my maintenance log with details of everything that I have done so far: http://goo.gl/ts47Uv

I took her out on a short ride today, and she ran very nicely. Felt smoother, sounded better and was a blast to ride. Smooth power though the entire RPM range.

The next things to do are to rebuild the electric starter clutch and replace the fork fluid. I think these can wait for a while though while I just have fun riding for a bit.

Here is a short photo log of the process:

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IMG_20141217_202302.jpg
 
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