Honda Twins banner

1 - 8 of 8 Posts

Registered
Joined
6 Posts
Discussion Starter #1
So I've recently bought another project bike. I have a 79' Cm400T that's minty and perfect. Bought roughly the same bike and it fired up when I first got it. Battery was dead so I waited to get one when I order tubes tires and misc. Stuff. So my issue. Threw me off guard. I have so spark with a battery hooked up but if I unhook the battery I can kick it and it'll fire right up. Any leads on what's the cause? I've already swapped the CDI for a known good (off of my other bike) also the coil is new.

I'll post photos of both soon 馃槉 thanks for any help with this. Has my mind boggled lol

-Dan
 

Registered
Joined
6 Posts
Discussion Starter #2
Also everything works electronically but the horn. Also someone has jumped the kickstand saftey I believe. Just ran a loop back in the wires
 

Registered
Joined
1,403 Posts
Are you talking about no spark on the 450 T or the 450 A. They are different systems. The 450 T CDI wont work on 450 A. Which bike are you working on ?????

Both will run without a battery. Battery is just for lights and starter. IF its an A model the side stand switch shorts out the CDI so the motor so it wont run in gear with the stand down. Un hook the wires and tape them off till we get it sorted out.

Bill H
 

Registered
Joined
6 Posts
Discussion Starter #5
Are you talking about no spark on the 450 T or the 450 A. They are different systems. The 450 T CDI wont work on 450 A. Which bike are you working on ?????

Both will run without a battery. Battery is just for lights and starter. IF its an A model the side stand switch shorts out the CDI so the motor so it wont run in gear with the stand down. Un hook the wires and tape them off till we get it sorted out.

Bill H
Hey Bill! Yes sorry I'm working on the 1982 cm450a. Bit excited to show off the bikes. Bought a new old stock cdi specifically for the CM450A off of a parts guy on eBay to have as a spare. Noticed they were different between the CM400T and the CM450A.

So the loop someone had made to Bypass the kickstand sensor/switch will be the no spark issue when I hook a battery to it? So then just disconnect the loop and electrical tape the ends. When my parts come in I'll give it a go. The Fuse panel is also deteriorated and the bottom fuse fell out when I opened the cover. Tabs for to hold the fuse in seems to have snapped off.

This bike is going to be one heck of a project. I need to get the manual for it. Need to fix the leaking oil cooler, leaky front forks, smashed headlight trim ring and bulb, smashed spedo and gear indicator also the main light panel in the center is unrecognizable. Needs a rear tire. I've got this bike for a steal for the girlfriend. Guy I got it from gave up on it after investing 1,200$ into it. Just spent about 600 in parts. Going to look at the oil cooler and see why it's leaking here soon and order parts for that as needed.

Parts list-
1. New used seat in decent condition
2. Entire CM450A cluster
3. Headlight bulb and trim
4. Front fork seals and driver with oil
5. Kenda Challenger rear tire. (Front is only worn .1" and from 2015)
6. Crash bars.
7. New grips
8. Horn (Original wasn't working)
9. Fuse panel
10. Left side cover
11. Complete engine gasket set. (Figured I'll need them eventually)
12. Kickstand switch

-LaFondathehonda
 

Registered
Joined
1,403 Posts
there are several items on the A model that can cause a no spark issue. This is just a suggestion but the motor will run with out a battery ,switch on, kill switch on run , kick start only. Motor in neutral as the kick start wont work with the motor in gear. I would make sure the motor is running first.

Tape off the wire from the CDI to the side stand switch till we test the change switch transistor.
You need a FSM but I can talk you thru the tests on the change switch and relay. You will need to repair the fuse panel first.
There are several stickys in the elec section for the 400 As you should read.
Dont buy a kick stand switch till we test the old one unless you know its bad. Also pick up a seal kit with the gasket set. Look on CMS for the o-ring seal for the oil cooler it doesnt come in the gasket set .You can get the part # and see if you can find one in the states.

Just some thoughts.

Bill H
 

Registered
Joined
6 Posts
Discussion Starter #8
there are several items on the A model that can cause a no spark issue. This is just a suggestion but the motor will run with out a battery ,switch on, kill switch on run , kick start only. Motor in neutral as the kick start wont work with the motor in gear. I would make sure the motor is running first.

Tape off the wire from the CDI to the side stand switch till we test the change switch transistor.
You need a FSM but I can talk you thru the tests on the change switch and relay. You will need to repair the fuse panel first.
There are several stickys in the elec section for the 400 As you should read.
Dont buy a kick stand switch till we test the old one unless you know its bad. Also pick up a seal kit with the gasket set. Look on CMS for the o-ring seal for the oil cooler it doesnt come in the gasket set .You can get the part # and see if you can find one in the states.

Just some thoughts.

Bill H
Okay Bill! I'll look at those forums. Also the bike runs without a battery. Key switch on and kill switch on run.

Now for my findings with a battery attached and that kickstand switch loop someone made disconnected. Also the new fuse panel in.

The neutral indicator is lit up. Electric start works. No spark. Replaced the horn with a known good because it wasn't working. Still not working and no spark. Theirs also a large box with a toggle switch by where the CDI is. Don't have that on my 79' but in both positions no spark still. But the odd thing. In one position all the lights flash up front when I kick the high beam on. Wonder if that's a aftermarket hazard light controller?? Also going to repair the rear light harnesses that was rubbed through from an oversized man I'd assume. Someone attempted to repair the wires with twisting them together and wrapped with electrical tape. Still no change and no spark. Just had a random thought. The rear running light isn't working. Going to replace the bulb and come right back to writing this.

Had found the right turn signal bulb blown as well. Replaced both and tried the electric start and no spark. I had a random idea to try and kick it with the battery and guess what. It fired right up and had spark. The right rear turn signal also with a new bulb still isn't working. Going to run through that and get it working.

The only tampered wires on the bike were the kickstand switch and the rear light harness over the fender.

Any narrowed leads from here would be amazing Bill!

-LaFondaTheHonda

Ps. My Red 79' is named laFonda
PSS. Attached are pictures of the electricals in question.
312957
312958
312959
312960
 
1 - 8 of 8 Posts
Top