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Discussion Starter · #1 ·
Hi all,

Well yesterday I brought home my very own CL350 that was previously molested by god knows how many. Fingers crossed that the problems don't go too deep!
You can see some pictures in my welcome post here.

Day 1
After trailering the bike home, I noticed the seat lock plunger was missing. I was given a number of boxes of parts, so I went looking through them. Low and behold I came across the plunger and hardware in a ziplock bag. However, I am gladf I tested the lock before installing the plunger on the seat, as it seems the lock is broken (in the bad way - the plunger can't be released. After a lot of curse words, I got the lock off the bike and the plunger out of the lock. Turns out the small metal cam that attaches to the end of the lock cylinder was in 10 or so pieces, so it couldn't draw the latch back. My google-fu could not uncover that part, so I ended up ordering a chinese re-pro lock off ebay and will try that for the mean time. Ideally, I'll pick up an OEM lock and install the lock pins from my lock to keep it keyed alike.

Day 2
Today I decided to tackle the carbs. I know the bike sat for a number of years, and had no real storage done, so my expectations were the worse for those carbs. First step was wheel it into the shop. Unfortunately my wife has taken over the garage for storage etc, so I am stuck in the backyard shed I have converted to a workshop. However, it is small. Like 100 sqft small. Oh well, gotta work with what you have.


- Removed the seat and tank. Never having a bike with a balance tube was a rude awakening. What I assumed was a vent or drain was the balance tube. Oops.
- Removed the carbs.

I drained the float bowls and started work on one carb. Diaphragm and needle assembly looked good - still pretty pliable. The carbs actually looked pretty good on the face of it. A little dirty on the outside, but not much varnish or crusties inside. I have not worked on these carbs before (plenty of time in CBR and Valkyrie carbs though...), and I was surprised how different these are. The lack of thread jets threw me for a loop. At this time, I fired up youtube and watched some of CMC's video on disassembly. I notice the plug for the low speed jet was not the black rubber, but some tan looking material. It was hard as a coffin nail - obviously original rubber. Fortunately the PO had bought a rebuild kit, which included the black 'top-hat' plugs, so I set about using a dental pick to break apart the rubber.


What I found next I can't quick explain. Under the plug was some wadded up aluminum foil or something.


I can't imagine how, or why it would be there. Ideas?

I removed the mixture screw, noting the LH carb was set to 4.75 turns out... seems like a lot but again - not used to these carbs. After removing the mixture screw and spring, I did not find an o-ring or metal washer (in either carb in fact). According to CMC's video, it should have them. I have a few extra carbs, so hopefully I have some spares.

I left the emulsion tubes in, but threw the carb, float bowl, and some metal parts (no o-ringed stuff) in a hot ultrasonic cleaner with some Simple Green. This typically works wonders in cleaning crap out of the passages (coupled with Carb cleaner and compressed air).


While the LH carb was in for a massage, I started on the RH carb. Similar story to the previous one, down to the old plug and tin foil surprise...


Slow jet before and after ultrasonic


Unfortunately, while that really bad looking jet did clean up in the ultrasonic, I can't see through it still. I will try guitar wire. These slows are #35, but I do have a set of brand new #38 from a carb kit. Not sure if anyone used those...

After about 45 minutes of trying to get the round o-ring in the pentagon shaped bowl groove, I gave up and decided to get some sleep. Back to it tomorrow...
 

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Noooooo... Don't use Guitar wire.
Find some Copper Wire to push thru the jets.
The Copper Wire won't scratch or bugger up the internals of the jet the way the guitar string wire will.

Also there are Felt Washer on each end of the throttle Shaft that need to be greased or coated with a heavy gear oil, and can only be accessed by removing the Throttle plates.
They act as seals to prevent vacum leaks behind the throttle plates.
Not simple proces as the screws that secure the plates are PUNCHED to prevent them from backing out and getting swallowed by the intake valves.

You will need to work them back & forth using ONLY a JIS type Screw Driver or you "WILL" most likely strip the heads.
Use RED Locktite when putting the screws back in to secure them.
 

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Discussion Starter · #3 ·
Thanks for the head up Yendor. I've never bothered with throttle plates before (provided they move freely). I'll look into those felt washers tonight...
 

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Discussion Starter · #5 · (Edited)
Are you keeping the color scheme? I like the tank and seat!

That aluminum foil sure is strange... I wonder what the PO was thinking?
I am keeping the seat as is, just needs a good scrub. The tank needs a total overhaul - full of rust and scale. I will deal with the inside, and plan on painting the tank Bordeaux Red metallic. I will be ordering some new honda decals from etsy as well :).

I mentioned the foil to a grey beard motorcycle guy who has been knee deep in many a carb - his response was along the lines of WTF? I guess I won't be replacing the foil on rebuild :grin:

Any thoughts on bumping the idle jets to #38? I have 115's and 70's in as well, live at sea level and the exhaust is a little wider open than stock. Carb wizardry is not my strong suit, so please bear with me!
 

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I have heard of people who have successfully Re-Oiled the felt washer by vacum.

They reallyhave nothing to do with the plate moving freely.
The Throttle Cable will provide enough leverage to the shaft to move them and the spring will return them home no problem.

The Felt Washers Swell up with the Oil and SEAL the shaft for Vacum Leaks (sucking in air behind the throttle plates where it doesn't get mixed with fuel.

The Vacum process I referenced it to close off with Heavy Duct Tape one side ot the carb then attach a vacum Hose to the other side either intake or cylinder side doesn't really matter which goes to which end.
Then apply vacum and dribble oil into the the sliver of space between the carb body where the throttle shaft are and allow the vacum to suck the oil onto the washers.

I've not tried it but I have seen some posts from people who said it worked.
I would be looking for a dribble of OIL on the inside of the carb throat to detemine if it worked or not.
 

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Discussion Starter · #7 ·
Day 3

Well today I finished off with the carbs for now. I will likely need to deal with the felt washers as Yendor pointed out - but I wanted to make some more headway on the engine. I started by removing the plugs, stator cover and point and tappet covers. Reset the cam chain tensioner (way easier than I thought it would be). Next I went through the valve clearances. Both intakes were good, around 2-3 thou. The right exhaust was a bit tight, but the left exhaust was REALLY tight. At LH Comp TDC there was no play on the tappet. I reset that valve clearance, turned the bike over a few times and re-checked - all stayed put.

Hooked a new battery up and checked all the electrical (lights, signals, brake lights)... all good.

Next was checking compression. The PO reported the bike had low compression due to a head gasket leak (there is some oil leaking, so I have no reason to doubt him), however with the tight exhaust valves - maybe that was a factor. Turned the bike over and it sounded good. My compression meter is of questionable quality, but it was worked in the past (I think). Basically 0 on the left cylinder and barely 30 on the right, and no sustained pressure (returned to 0 immediately). My hope is stuck rings so I'll drop some seafoam down there and hopefully loosen it up. Thing is though, when the plugs were in and I was kick starting, there was some definite resistance and felt like there was comp. Leg got tired after a while lol. And I tried plugging the left plug hole with my thumb and turning it over, but it blew it off... so there must be some comp?

Tomorrow is another day!
 

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Compression is best tested with the Carbs OFF.
If that isn't a simple option Throttle PLATES WIDE OPEN.

How long is the hose between the spark plug hole and the indicator for your compression tester?
Long hoses typically show low compression values.
 

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Discussion Starter · #9 ·
Compression is best tested with the Carbs OFF.
If that isn't a simple option Throttle PLATES WIDE OPEN.

How long is the hose between the spark plug hole and the indicator for your compression tester?
Long hoses typically show low compression values.
Carbs are off the bike still. The compression tester is a cheap one. The style that uses a quick connect to lengths of hose terminated with various spark plug threads. Even with the slightly longer hose length, I'd still expect to see some comp.

Seafoam is in and hopefully it is just a stuck ring or something. Although hope is not a strategy...
 

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Discussion Starter · #10 ·
Day 4

I spent the day at work thinking about this bike. I hate having outstanding questions like this. Thinking about it today - my 0 compression problem CAN'T just be the engine, as it feels like there is comp when you kick it over. I hooked the gauge directly up to my air compressor and compared the readings. The compressor showed about 95 psi at the reg, but the comp gauge only showed 60... Moral of the story, BUY GOOD GAUGES! :rolleyes:

I replumbed the comp gauge on the engine with some different fittings and tried again on both cylinders. Both read 90 psi. Depending on how you look at it, maybe that means between 125-140 psi. I will get a good gauge tomorrow and verify. Still a bit low, but this is a cold engine that has been sitting for years with just some oil squirted in each cylinder. There is hope yet...

Because I wanted to ride my happy wave, I squirted a bit of fuel in the cylinders, threw in some new plugs and figured see if she runs. However, after a few cranks the battery died :\ Glad there is a kick starter! 2nd kick she roared to life for a second. Pretty happy with that :)
 

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Day 4

I spent the day at work thinking about this bike. I hate having outstanding questions like this. Thinking about it today - my 0 compression problem CAN'T just be the engine, as it feels like there is comp when you kick it over. I hooked the gauge directly up to my air compressor and compared the readings. The compressor showed about 95 psi at the reg, but the comp gauge only showed 60... Moral of the story, BUY GOOD GAUGES! :rolleyes:

I replumbed the comp gauge on the engine with some different fittings and tried again on both cylinders. Both read 90 psi. Depending on how you look at it, maybe that means between 125-140 psi. I will get a good gauge tomorrow and verify. Still a bit low, but this is a cold engine that has been sitting for years with just some oil squirted in each cylinder. There is hope yet...

Because I wanted to ride my happy wave, I squirted a bit of fuel in the cylinders, threw in some new plugs and figured see if she runs. However, after a few cranks the battery died :\ Glad there is a kick starter! 2nd kick she roared to life for a second. Pretty happy with that :)
I am pretty sure this bike still requires a fully charged battery to operate correctly.
 

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Discussion Starter · #12 ·
I am pretty sure this bike still requires a fully charged battery to operate correctly.
Battery was still hooked up. Enough juice to fire the plugs, but not enough to turn it over very fast.

Day 5

Back at it tonight. My weekend ended up being totally booked so I really didn't get anywhere. Today I ordered a bunch of parts:

- New coils. While poking around, I noticed the HT leads were cracked near where they are molded into the coils. Moved the LH lead a bit and it fell off. Looks like a PO stuffed some wire in there to make it work. Obviously not a reliable

RH side was intact, but very cracked. I bought a pair from Scrambler Cycle in WI.
- New petcock. The pickup tube is split down to the base, and a replacement was only US$14. Again, through Scrambler Cycle.
* Aside: it turns out the tank was not all rusty and scaley. I drained the tank of fuel in preparation for paint, and the fuel came out totally clean. I poked at the 'scale' a bit and it turned out to be some sort of conformal coating I have never seen before. Good news!
-Inline fuel filters from Amazon (just in case!)

- Decals for the tank. Went with the classic Honda wings.
h2a__04614.1499995039.1280.1280.jpg

- A manual impact driver for those oil filter screws.

Also, I borrowed a good quality comp gauge, and got 150/180 psi cold. Very happy with these numbers. The left is the side which may have a head gasket leak, so that may explain the lower number. Still within Honda specs, though.
 

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Also, I borrowed a good quality comp gauge, and got 150/180 psi cold. Very happy with these numbers. The left is the side which may have a head gasket leak, so that may explain the lower number. Still within Honda specs, though.
Sorry, but they are NOT within spec.....Honda specs 15 PSI as the maximum pressure variation between cylinders.......
 

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Clymer has it listed as a 25%. Maybe thats not right :confused:
You'll find that many critical specs found in other manuals are not correct... trust the FSM and frankly, to imply that 25% variance is okay is crazy to me... one cylinder 25% less efficient than the other? it isn't like it's human and can think to compensate for the difference, it would be pretty weak overall (though 150 equal on both would still run fairly decent)
 

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Gotta be a typo.....Minus 25 PSI is about correct for the suggested re-ring/rebuild minimum ...
(this would be ~145 PSI on a 350)...
At this point, your engine is only producing about 85% of the HP of which it is capable, assuming both cylinders have equal compression PSI, and are running well balanced (carbs and spark timing)....
Difference in cylinder PSI (allowable variance) maximum is always below 10%, usually closer to 8.5 to 8.8%......
 

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Discussion Starter · #17 ·
Day 6

Bit of a late update. I got the tank bondo'd and primed last night. Not too happy with the result so I'll be doing some more sanding and priming tonight.

I placed an order now new chain and sprockets, chain lube, fork oil, grips and clutch/brake levers. Looking forward to getting some of those items dealt with.

I was looking at replacement tires. I think this bike currently has MT66 tires on it, but they are meh. I've done tons of searching for the best modern tire replacement, but haven't decided on anything yet. According to a metric conversion chart, it looks like a 100/90/19 will fit on the front, and a 110/90/18 on the rear, but it looks like those might be too wide and have fitment issues. Any recommendations on a modern tire? I was looking at the Avon AV26 Roadrider in 90/90/19 and 100/90/18, but it looks like those are front tires for both sizes. Any issues running a front on the rear?
 

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Ditch the Clymer manual and download the Honda FSM from the Common Motor Collective manuals page on their site.
 
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