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This was originally written for SOHC's but much of it still applies
Congratulations, you are the proud owner of a Honda Twin :D . One that may or may not have been maintained properly :eek: . Of Course, the previous owner (PO :evil: ) told you that everything is absolutely perfect and the oil was just changed and he rides it every day and has never had a problem with it. Yeah, right :lol:
OK, so it started, you rode it around a little and it seems ok. Or maybe it didn't and you bought it anyway.
So let's cover the things that you should take a good hard look at to make it safe and sound.
First go here and download the Factory Service Manual (FSM)
viewtopic.php?f=57&t=13568
ENGINE:
Check the compression, spec is 185psi, to see where you're really at. Don't be expecting that number though. 135 is pretty much the lowest you can get and still have it run, albiet not good but run. You want both cylinders to be reading very close to each other.
Adjust the valves. Simple to do and rarely did the PO ever do it even though the Maintainance Schedule (MS) calls for every 6K. Now is a good time to put in new properlu gapped plugs.
Change the oil and filter even though the PO said he did. You have no idea what he used. Correct oil is a motorcycle rated 10-40w conventional oil. No blends or synthetics allowed since this is a used motor and a wet clutch. When you go to start it, leave the kill switch off while cranking until you see the pressure light go out. Now you can actually start it.
Check the balancer chain adjustment. See the FSM that you've downloaded.
Check the cam chain adjustment. See the FSM that you've downloaded.
TRANSMISSION and DRIVE:
Check the clutch adjustment. See the FSM you've downloaded.
Check the chain adjustment. See the FSM you've downloaded.
Check the condition of the chain and sprockets carefully. The chain should have a max side to side play of @3/4" and each link should be able to move freely. The rear wheel should have no stiffness/drag in certain positions since that indicates the chain is binding. The sprockets should have a nice even valley between each tooth and the teeth should have a flat area at the tip, no pointy teeth allowed.
BRAKES:
Inspect the linings/pads for wear, cracking and delamination. Delam is where the actual lining is seperating from the backing plate.
Lube the contact points of the pads/linings
Lube the caliper slides and pins
Change the brake fluid. Should be done on a regular basis. See the FSM you've downloaded.
Adjust the brakes. See the FSM you've downloaded.
FRONT FORKS and STEERING:
Drain and refill the forks with the proper amount and type of oil. Yes, it normal for it to come out looking and smelling really bad. That's cause no one ever did it. :lol: See the FSM you've downloaded.
Inspect the steering head bearings, lubricate and adjust. See the FSM you've downloaded.
Check the torque of the triple trees clamping bolts. See the FSM you've downloaded.
REAR SUSPENSION:
Remove the rear shocks. Try compressing them against the ground. Won't move? They're frozen up and have to be replaced, They compress really easy? They're blown and need replacement. They move some but stiffly? May be they're OK.
Remove the rear swing arm to clean the swing arm bushings and pivot points. Replace the zert/lubrication fittings since the old ones have a habit of freezing/plugging up. See the FSM you've downloaded.
WHEELS:
Spoke/Wire wheels need to have each spoke checked for being intact and tight. Missing spokes are a big no-no. Loose spokes are a no-no. Test each spoke for tight and then tap it with a wrench. You should hear a ring note. Each spoke should have the same sound. If you get one that doesn't have it, it's an indication something is wrong with it. Possibly cracked.
Inspect for rim damage like dents in the edge.
COMSTAR wheels need to have the rivets checked for tightness. Loose rivets mean rim failure and no they cannot be replaced.
Inspect for rim damage like dents in the edge.
Check the wheel bearings for smoothness of rotation. There isn't such a thing as "it seems ok" or "just a little roughness". That's like being a little bit pregnant.
TIRES:
Inspect them carefully. Your life depends on them :eek: ! Here's a link with good info about them http://www.roadrunner.travel/magazine/r ... 6/page/32/
The tires generally can be increased in size by 1 number, 100/90 to 110/90, but there's no real point to doing that unless you need more load rating of the tire or ride exuburantly/aggressive.
Tube type tires should have a new tube every replacement even though they look ok.
Always check the tire pressures before riding!
ELECTRICAL:
Check the battery. If it's the normal lead acid type and more than 2 years old it's done even though it seems ok right now. If it's an AGM type then get it load tested. When in doubt replace it.
Check the fuses and connections. Typically the fuse connections are corroded and need to be cleaned to get a good connection and not overheat. The standard auto fuse is not the correct length and can cause problems.
Check that the lights all work including the brake light from both the lever and foot pedal.
CABLES:
Take the cables off the bike. I know, the throttle cables are PITA. :lol: Disassemble them where possible, clean and lubricate with motor oil. The ones that don't come apart flush them with a solvent, let them dry for a couple of days and lube them with a good quality cable lube.
FUEL/INTAKE: Thank's to 'steveo' for this addition
Take off the fuel tank cap and petcock sediment bowl and look for rust and contamination.. use a flashlight.. at the very least least install an inline filter in the fuel line if the tank is rusty or the sediment bowl is full of "stuff". actually, just install the filter anyway.
Take out the air filter and inspect it, if it's dirty, the bike will run like crap.. they're very sensitive to air filter condition
Take the plugs out of the 'drain tubes' that come off the airbox, if equipped. a bunch of oil, water, and disgusting crap will probably come out of them.
Attach some short peices of tube to the float bowl drains, and crack 'em open. if the fuel that comes out is not completely spotless and clean, just pull the carbs right off and start taking them apart, it's worth it. if there's any particulate in the float bowls, that means there's probably stuff clogging your jets
Even if the carbs are clean, think about balancing them soon.. on an old bike, they're probably way out

Now that you've become intimately familiar with your new bike and everything is in order, go ride and have fun knowing that everything is good and will get you home.
 

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Discussion Starter #2
Yeah, I know. This just took alot of time to do and you've spent more money than you wanted to before really riding. IT will save you a lot of grief down the road though.

On a personal note: I do all of this on each and every bike I've bought. I actually replace all of the wheel bearings regardless of how they feel since that was the cause of my first serious crash at 75mph just in front of a logging truck. The HD shop I was roadtesting for thought they felt pretty good.
 

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i think this is important too..

FUEL/INTAKE:

take off the fuel tank cap and petcock sediment bowl and look for rust and contamination.. use a flashlight.. at the very least least install an inline filter in the fuel line if the tank is rusty or the sediment bowl is full of "stuff". actually, just install the filter anyway.

take out the air filter and inspect it, if it's dirty, the bike will run like crap.. they're very sensitive to air filter condition

take the plugs out of the 'drain tubes' that come off the airbox, if equipped. a bunch of oil, water, and disgusting crap will probably come out of them.

attach some short peices of tube to the float bowl drains, and crack 'em open. if the fuel that comes out is not completely spotless and clean, just pull the carbs right off and start taking them apart, it's worth it. if there's any particulate in the float bowls, that means there's probably stuff clogging your jets

even if the carbs are clean, think about balancing them soon.. on an old bike, they're probably way out
 

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longdistancerider said:
No blends or synthetics allowed since this is a used motor and a wet clutch.
I have to disagree with this. I've run synthetic in old engines and in motorcycles with wet clutches for decades without issue. As long as the synthetics are listed as appropriate for wet clutches, they're fine. In fact, with their vastly superior thermal properties, I'd strongly recommend them for air-cooled engines. On hot days I've seen a simple switch to synthetic drop oil temps by 30 degrees Fahrenheit.

Also, 20w50 is perfectly acceptable as long as temperatures stay above 15 degrees Fahrenheit (-10 centigrade) per the factory shop manual.

These are helpful to know if you have multiple bikes and want to standardize on one type of oil.
 

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Discussion Starter #7
Thanks, Nigel.
Zemnervolt, don't get me wrong here. I have nothing against the synthetics and blends. I like them for the very qualities you've mentioned. I wrote this for the person who has just bought a older bike with questionable maintainance. And a bike that is been run on conventional oil most likely. From past experience of trying to switch from conventional to synthetic I have always run into clutch slippage under high stress loads. Now if the discs, steels and pressure plate are replaced with new ones there is no problem.
10-40 vs. 20-50: there's always that long standing debate :lol: I use 20-50 when I'm dealing with an average daytime ambient temp of 85+ and 10-40 when it's cooler than that. Lately the avg amb temp here has been @95. 110-115 @3pm and 75 @3am. So yeah, I'm running 20-50 and will be thru September.
 

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longdistancerider said:
Thanks, Nigel.
Zemnervolt, don't get me wrong here. I have nothing against the synthetics and blends. I like them for the very qualities you've mentioned. I wrote this for the person who has just bought a older bike with questionable maintainance. And a bike that is been run on conventional oil most likely. From past experience of trying to switch from conventional to synthetic I have always run into clutch slippage under high stress loads. Now if the discs, steels and pressure plate are replaced with new ones there is no problem.
10-40 vs. 20-50: there's always that long standing debate :lol: I use 20-50 when I'm dealing with an average daytime ambient temp of 85+ and 10-40 when it's cooler than that. Lately the avg amb temp here has been @95. 110-115 @3pm and 75 @3am. So yeah, I'm running 20-50 and will be thru September.
Fair, though I'd still say that they're probably better off putting in a new clutch and using a motorcycle-formulated synthetic, especially with an air-cooled engine. :)
 

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Discussion Starter #10
tylerkaz said:
good info, thanks for the manual links, but how would a wheal bearing make you crash? is it from the wobble?
It was a front wheel bearing, left I think. Think of the front wheel as a gyroscope, remeber that silly little toy? If you suddenly stop one end of it, the bearing, it'll fall over. I'd just passed the truck and was still straightening up when it happened. To make it worse it had 12" extended forks.
If it'd been a rear I probably would have been ok.
Major reason I wear full gear all the time regardless of temps. ATGATT. :D
 

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longdistancerider said:
tylerkaz said:
good info, thanks for the manual links, but how would a wheal bearing make you crash? is it from the wobble?
It was a front wheel bearing, left I think. Think of the front wheel as a gyroscope, remeber that silly little toy? If you suddenly stop one end of it, the bearing, it'll fall over. I'd just passed the truck and was still straightening up when it happened. To make it worse it had 12" extended forks.
If it'd been a rear I probably would have been ok.
Major reason I wear full gear all the time regardless of temps. ATGATT. :D
Scary stuff right there, glad you're ok.
 

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theamazingkenny said:
Scary stuff right there, glad you're ok.
The body heals, still get a cold chill in my spine everytime I pass a logging truck though. It's the only accident on a bike I say wasn't my fault, although it really was because I trusted these guys to have built the bike correctly since that was their business. I knew they took short cuts at times.
 

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longdistancerider said:
tylerkaz said:
good info, thanks for the manual links, but how would a wheal bearing make you crash? is it from the wobble?
It was a front wheel bearing, left I think. Think of the front wheel as a gyroscope, remeber that silly little toy? If you suddenly stop one end of it, the bearing, it'll fall over. I'd just passed the truck and was still straightening up when it happened. To make it worse it had 12" extended forks.
If it'd been a rear I probably would have been ok.
Major reason I wear full gear all the time regardless of temps. ATGATT. :D
Same here. A guy I work with refuses to wear protective gear aside from a helmet (law) and a leather jacket. In fact, he just told me today that he hates the very jacket I wear because the shoulder vents turn the jacket into a parachute (of sorts), which I agree with. However, I'll take proper protection and armor over leather and 'years of experience' (his words). Plus, the those vents can be closed while leaving others open to reduce drag. I scratched my head a bit on this one.

But to each their own, right? I have yet to find out if he's ever crashed or not. For some, it will take a crash to discover the importance of safety, and proper gear. Besides, living up here in the NW, it doesn't even get that hot usually. Typically in the 80's during the summer. Not bad compared to elsewhere in the country. I'd be more concerned about having waterproof gear since it rains a lot up here.
 

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Im 5 days away from picking up my first bike, a 1982 cm450, and I wanted to say thank you for posting the link to the manuals (saved me some $ there) and for writing up the checklist (possibly saving my life).. for someone like who has zero practical experiences with motorbikes it is very helpful and a great answer to my question... "where do i even start?!?" ...Im sure ill be posting questions and photos once I get the bike home and clear out the garage space to tear it apart- until then thanks for the valuable resource!
 

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Discussion Starter #15
Welcome aboard :D
We're all here to help each other and learn. You might want to go to the 'Member Intro' section :)
We do like our pictures here also :lol:
 

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Regarding the balancer chain adjustment... When doing the first oil change you may as well pop the right side cover while the oil is out and make sure the balancer chain adjuster is not stuck. Mine was, even after I loosened the nut the adjuster didn't move. I had to manually apply some pressure to get it to break free and only then did it adjust itself automatically as expected.
 

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i think this is important too..

FUEL/INTAKE:

take off the fuel tank cap and petcock sediment bowl and look for rust and contamination.. use a flashlight.. at the very least least install an inline filter in the fuel line if the tank is rusty or the sediment bowl is full of "stuff". actually, just install the filter anyway.

take out the air filter and inspect it, if it's dirty, the bike will run like crap.. they're very sensitive to air filter condition

take the plugs out of the 'drain tubes' that come off the airbox, if equipped. a bunch of oil, water, and disgusting crap will probably come out of them.

attach some short peices of tube to the float bowl drains, and crack 'em open. if the fuel that comes out is not completely spotless and clean, just pull the carbs right off and start taking them apart, it's worth it. if there's any particulate in the float bowls, that means there's probably stuff clogging your jets

even if the carbs are clean, think about balancing them soon.. on an old bike, they're probably way out
Is there a certain fuel line filter you guys recommend??
 

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Hi,Longdistancerider,Thank you for your very valuable info.When i have more time i will post pics of the bike and tell the history and progression of restore.
 

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Discussion Starter #20
I will have the Honda FSM for this in the library in a couple of days if you need it
 
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