78 Honda Twinstar CM 185

[Guest]

A family member bought this bike new in 1979, put 1200 miles on it, then put it in the garage and forgot about it. Now they just want it gone. It's in pretty good shape cosmetically, but they say they are pretty sure the engine is seized up from sitting so long. 10 years ago or so someone apparently tried halfheartedly to get it started and failed. Otherwise it hasn't been touched.

Now the family has offered it to me for free if I haul it away. It would make a great bike for the wife (she really likes how small and light it is), but if the engine is seized from sitting for 35 years is it even going to be worth trying to get running again?

 

[LarryJ]

Worst case, it'll need a reborn & a set of pistons. NBD.

 

[Nessism]

Most likely it's not seized. I'd take it. As LaryJ says, worst case have it bored or go find yourself a good used cylinder and pistons.

 

[Guest]

Awesome, thanks for the input guys. I've never tried to fix anything like this before, any advice on exactly where to start? I had a friend tell me about some kind of liquid I can pour into the engine and let sit for weeks to try to get it going again, but that seemed iffy. I'm not against taking it to a mechanic to have it done if it's not super expensive, but I'm starting to get a little more comfortable around these giant science projects we call motorcycles, and would love to try to see what I can do myself first.

 

[steve murdoch]

They are a fun little bike.
I fixed up a couple of them for my sister and niece who were both 5' tall with short legs.
The rubber mounted buckhorn handlebars are goofy but the foot controls are in the proper place and not forward mounted like the Rebel.
6 volt system.
www.hondatwins.net is an excellent site for that bikes.

 

[Jedz123]

I had a Twinstar 180, it was awesome! I put an aftermarket mikuni carb on it to just be done with it. Ran like a CHAMP! But could never get it to go over 60mph . It was an awesome bike, got it for a buddy to learn to ride. Took it in for $250 not running with brand new parts and a fouled carb, new carb and kept it for a summer to train a buddy then sold it for $1350 in the fall. Easiest cash I ever made...

Everyone loves those little bikes.

 

[Big Rich]

Try any of the normal penatrating oils (look here: http://www.cyclefish.com/forum/The-...s-best-on-Rusted-Nuts-amp-Bolts-132611-1.html) and pour it into the spark plug holes, and let it work for a day or three. Forget about trying the electric starter btw. Take the spark plugs out, and put the bike into 2nd gear, and rock it forward & back a couple times. If it is slightly stuck, the leverage from the transmission can break the pistons free.

But absolutely make sure the spark plugs are out when you try it.

 

[chuck hahn]

The mechanics back in the day used a 50/50 mix of ATF and Acetone. Few ounces down each plug hole and let it set a few days. Use the rotor wrapped in an old leather belt and some huge channel locks to start the back and forth to get the pistons moving.

Guy named Anthony here got ahold of a stuck GS 1000 a few years ago and he did as i just said and it has been running since. Smokes like crazy at start up but that burns off in a while. Get it going and do a compression check to see how it is.

 

[RichDesmond]

Awesome, thanks for the input guys. I've never tried to fix anything like this before, any advice on exactly where to start? I had a friend tell me about some kind of liquid I can pour into the engine and let sit for weeks to try to get it going again, but that seemed iffy. I'm not against taking it to a mechanic to have it done if it's not super expensive, but I'm starting to get a little more comfortable around these giant science projects we call motorcycles, and would love to try to see what I can do myself first.

If it's not seized I'd pull the carbs and clean them (should be some tutorials on the net), change the oil, put a new battery in it and see if it will start.

 

[Guest]

So, I got it home today. I don't think the pistons are stuck. I can move the kick start all the way through and it has some pressure as I would expect. I can also push it while in gear and feel parts moving (I think). Changed the oil. The bike is in great cosmetic shape. Some steel wool and almost all the chrome is in like new condition.

Now the bad. There is something wrong with the throttle. I haven't started it yet, but the throttle moves freely and doesn't snap back. I took it apart at the handebar and the cable is connected there, but it doesn't feel like it's moving anything on the other end. I traced the plastic cable all the way back to the engine, it's connected there, though I don't know how to see inside the plastic tube to see if it's actually connected at the top of the engine. Any ideas on that?

Also, in theory, should I be able to start this without a battery? I found a smaller 6V battery at a local batteries plus, but they suggested waiting a few hours before I hook it up since they just filled it.

Thanks in advance for answering a total noobs questions.

 

[Guest]

Also, when I twist the throttle I can hear a faint clicking noise where it connects to the carb, but I can't tell wtf is going on...obviously.

 

[Nessism]

Also, when I twist the throttle I can hear a faint clicking noise where it connects to the carb, but I can't tell wtf is going on...obviously.

Pull the carbs off and clean them. Make sure the tank is clean too and check the petcock. I wouldn't even bother trying to fire up an old bike like that until you have done a little maintenance.

 

[Guest]

Thanks for the response, I'll try to clean the carbs. I have super limited experience, but the tank looks really clean. As for the petcock, not sure what I'm looking for, everything connected to it is clean and in good condition, but I'm not really sure what I'm looking for...

 

[wymple]

I have a 200 Twinstar engine and a few miscellaneous parts . I think they are the same animal. Mine had a bent valve, engine ran pretty decent even with that. Let me know if you need anything. It was all good except the head problem. BTW, the carb was in good shape, a major plus.

 

[RichDesmond]

Thanks for the response, I'll try to clean the carbs. I have super limited experience, but the tank looks really clean. As for the petcock, not sure what I'm looking for, everything connected to it is clean and in good condition, but I'm not really sure what I'm looking for...

If you do go to clean the carbs, make sure that you have a set of JIS screwdrivers. All those "Phillips" screws you see on the bike? They aren't Phillips, and regular Phillips screwdrivers make if very easy to strip the heads.

http://www.thegsresources.com/_foru...94-JIS-Impact-Screwdriver-Thanks-for-the-post!

 

[Guest]

If you do go to clean the carbs, make sure that you have a set of JIS screwdrivers. All those "Phillips" screws you see on the bike? They aren't Phillips, and regular Phillips screwdrivers make if very easy to strip the heads.

http://www.thegsresources.com/_foru...94-JIS-Impact-Screwdriver-Thanks-for-the-post!

Nice, thanks!

 

[Guest]

I have a 200 Twinstar engine and a few miscellaneous parts . I think they are the same animal. Mine had a bent valve, engine ran pretty decent even with that. Let me know if you need anything. It was all good except the head problem. BTW, the carb was in good shape, a major plus.

Will do, thanks!

 

[Jedz123]

Also, when I twist the throttle I can hear a faint clicking noise where it connects to the carb, but I can't tell wtf is going on...obviously.

I bet the throttle cable disconnected from the slide of the Carburator. It's a VM style carb with the throttle cable connecting to the inner slide directly with a clip (which often falls out or never is reinstalled correctly) from the top of the carburetor... You have to pull the carb anyway but I bet that's the issue there...

 

[Guest]

Thanks Jedz. On the advice from some fellows over at hondatwins I lubed up the cable real good last night, but it didn't seem to make a difference. I'm going to pull the carb today which will let me know if the cable is disconnected.

Out of all the videos I've watched now on disassembling a carburetor, every single one starts with the carb already out of the bike. If there is still any old gas I can't siphon out of the tank, is it likely to come out when I disconnect the carb? Just wondering what to expect when I remove it.

 

[Nessism]

If the petcock is working properly it will stop the fuel from flowing when you pull the tank. Just make sure the lever is in the proper position. I'm not sure how that model petcock works so to test you have to do some research.

With the carbs off you will want to remove the floatbowl's and have a look. If there is any grunge then a full tear down is in order. If the carbs look very clean inside the float bowl then you will want to follow up by removing the pilot jets and holding them up to the light to be sure there is no blockage. This should be the absolute minimum you do.