Topic: Starting a CB450 from 18 years in storage. What's the proper start-up procedure?

[fendersrule]

So I picked up a '74 CB450 yesterday with 5,000 miles. It's been in storage for 18 years. Indoor, and under a tarp. I needs a new master cylinder, fork tubes, and a tach. Pretty simple external stuff. The engine however, appears to be in solid shape. The bike is mostly original, paint is still vibrant. Original pipes, all around very clean and zero rust.

Compression:
It was 105F outside (and I was working on this thing out in the sun), so I didn't have a chance to fully diagnose the engine. I did a quick "spot" compression check. Putting my fingers up to the spark plug hole revealed what "felt" to be a healthy motor. I used an automotive compression gauge (press-in type), and the bike showed 125PSI on both sides, with me kicking it over with my foot. I didn't run this at WOT throttle either (I was busy kicking the motor while also holding it up while my friend held the gauge in) and I didn't get a chance to check the valves. I had to work quick as I was burning my butt off. I expect the motor is very healthy, and once it gets hot, ran for a hundred miles, a valve adjustment, and with WOT then it probably would give healthy compression. I do have an actual motorcycle compression gauge on the way, so I'd like to start getting more accurate numbers (this gauge reads smaller engines low).

Tank:
The tank was halfway full with fuel. It needs to be drained. Where there wasn't fuel in the tank, there is some build up (loose, wet rust). It's a given that I will have to remove the tank, drain it, and use an acid treatment/flushing. Probably will use some bbs. I also plan on putting 2 fuel filters on.

Oil:
I didn't check the oil. But it's a given I will need to drain. Run the engine for a few hundred miles, and drain the oil again. Would you guys recommend putting in a little marvel mystery oil after I drain it to try to get as much residual stuff as possible?

Carbs:
Carbs were bone dry. They probably should be gone through. There are some cracked boots that need to be replaced. May clean the jets and try to use them as-is for the time being.

Air cleaner:
Did not look at, but I suspect that they are in great shape with only 5,000 miles of intake.

Spark Plugs:
Appeared to be in good condition and properly in spec. May replace anyways.

Battery:
Needs replacement, which is a given. Starter button works and turns the motor over.

I suppose after doing all that, then I should be able fire it up

[LesterPiglet]

My bike sat for 20 years. Just did a normal clean up and she started. Why replace jets?

[MoMo]

Jets rarely need to be replaced unless they have been mangled.  Compression is normal.  I use Seafoam rather than Marvel in a bike that has sat for a long period of time--one ounce per quart.  Also, one ounce per gallon of gas for the first couple tanks. Look at the air cleaners--I have had several that had been eaten by  mice.  It is rare to find exhaust in very good condition, you are lucky...Larry

[754]

 I * M * P * R * E * S * S * I * V * E *

[Stev-o]

Congrats, you stole it.  Sounds like a good plan.  A little oil in the cyl to provide lube to the rings might not be a bad idea.

[RAFster122s]

Change the oil, lube the cylinders and top end with new oil. Really should have lubed it before trying to get compression readings.
New air filter, tear down carbs and clean emulsion tubes and jets and polish float valve seat and float valve tip.
Clean and file and gap points. Replace condensors.
Adjust cam chain if so equipped.
Adjust valves to spec.
Evaporust or similar to remove rust from tank
Acid is nondiscrimenatory and eats good metal as well as rust.
Electrolysis is another good method, just more work to keep it working.

[FuZZie]

Naw... That stuff's all out of order first thing is post us a few pics! 

+1 on the seafoam

[vfourfreak]

I'd suggest you open the tappet inspection covers and squirt in copious amounts of oil.
+1 on oil in the cylinders.
I'd go so far as imediately draining the engine oil, refilling, and doing the above two steps. The top end will have drained and prolly be bone dry after that length of time.
Also, even though it was stored indoors, varmints may have set up home somewheres, so I'd suggest check the airfilters right away.

Kev

[strynboen]

vash the oilfilter in fuel..before any start try...dirt are storet in the sentifugal filter..it will break loose..at first start an spret dirt arraund in engine....klean the filter before oil shift

[vfourfreak]

vash the oilfilter in fuel..before any start try...dirt are storet in the sentifugal filter..it will break loose..at first start an spret dirt arraund in engine....klean the filter before oil shift

Agree, it will be full of a graphite type of s**t

Kev

[grcamna2]

+1 on putting something down ea. spark plug hole(just a little won't hurt!)to lube the dry cylinder walls.
I've always started w/ a few sprays of WD40..,it won't lube too much but when you spin it over w/o any plugs it'll help to scrape any surface rust off of the cylinder walls & then I'd put some 20 wt. oil in ea. cyl..,like about a teaspoon in ea.

Change the oil a few times after you do this.