Need electrical help...I'm dying here!!!

General forum on troubleshooting electrical problems and modifications to electrical systems

Moderator: rztom

Post Reply
Message
Author
thumper580
Posts: 60
Joined: Wed Jul 12, 2017 3:34 pm
Location: Virginia

Need electrical help...I'm dying here!!!

#1 Post by thumper580 » Fri Oct 13, 2017 3:03 pm

Bike was running great but needed to fix first gear in the transmission.

Pulled stator to get the transmission cassette out, replaced the gear cluster and installed new shift forks. put everything back together.

start the bike and the lower cylinders are running fine but the top cylinders are missing and farting and weak exhaust output.

new plugs....same
swapped coils....same
swapped orange and black wires from upper coil to lower coil and vice versa.....same
different plug wires on upper cylinder....same
Ohms on pick up leads checked out ok
Ohms on windings were alittle high, but barely
has a 4 degree key on the crank, switched it forwards and backwards.....same
tried a backup cdi.....same

I'm out of options and miserably frustrated....... Any magical suggestions???

User avatar
Rick Lance
Posts: 366
Joined: Thu Nov 17, 2005 11:12 am
Location: Leicester, NC
Contact:

Re: Need electrical help...I'm dying here!!!

#2 Post by Rick Lance » Fri Oct 13, 2017 4:09 pm

Did you paint anything while the motor was out? You may have a bad ground. Try running a dedicated ground wire from the stator cover to the upper and lower coils.
If I disagree with everyone, that doesn't make me right. If I take the side of only one, it doesn't end the fight. If my position's strong enough from exposure to the light, you may see things my way when we share the same highway.

User avatar
tacky1
Posts: 1248
Joined: Mon Sep 14, 2015 12:30 pm
Location: Bay Area. CA.

Re: Need electrical help...I'm dying here!!!

#3 Post by tacky1 » Fri Oct 13, 2017 5:17 pm

How long was the bike sitting, I would clean the carbs out, They might be gummed up from sitting, The ethanol is awful if you leave the bike sitting any length of time with ethanol blocker in the gas..
1985 RZv500
1984 RZ500 Hybrid
1986 RG500 Walter Wolf
1986 RG500 Skoal Bandit
1984 RZ350
1984 RZ350 Hybrid
1981 RD350LC
1981 RD350LC Hybrid
2009 CR500AF Supermoto 250X
2007 CR500AF 250X
1988 YSR50 (2)
1989 VFR750R RC30
1984 GPZ750 Turbo

thumper580
Posts: 60
Joined: Wed Jul 12, 2017 3:34 pm
Location: Virginia

Re: Need electrical help...I'm dying here!!!

#4 Post by thumper580 » Fri Oct 13, 2017 5:48 pm

tacky1 wrote:How long was the bike sitting, I would clean the carbs out, They might be gummed up from sitting, The ethanol is awful if you leave the bike sitting any length of time with ethanol blocker in the gas..
The bike was only down three days and ran perfect before pulling the transmission.

Paulrs
Posts: 67
Joined: Tue Sep 08, 2015 5:27 pm
Location: Royston, UK

Re: Need electrical help...I'm dying here!!!

#5 Post by Paulrs » Fri Oct 13, 2017 6:19 pm

As you pulled the transmission the clutch must have been off. Crazy question but have you double checked the cranks are in phase. The front crank has the rotor on it so would not be effected, not so with the rear crank and one gear tooth out could give the problems you describe.

If above OK try the carbs.

Regards
Paul

thumper580
Posts: 60
Joined: Wed Jul 12, 2017 3:34 pm
Location: Virginia

Re: Need electrical help...I'm dying here!!!

#6 Post by thumper580 » Fri Oct 13, 2017 7:38 pm

Paulrs wrote:As you pulled the transmission the clutch must have been off. Crazy question but have you double checked the cranks are in phase. The front crank has the rotor on it so would not be effected, not so with the rear crank and one gear tooth out could give the problems you describe.

If above OK try the carbs.

Regards
Paul
To pull the trans cassette you only take off the two nylon gears and the kick start gear, so both cranks never get changed or touched... These are on the clutch side of the bike.

thumper580
Posts: 60
Joined: Wed Jul 12, 2017 3:34 pm
Location: Virginia

Re: Need electrical help...I'm dying here!!!

#7 Post by thumper580 » Sat Oct 14, 2017 6:20 pm

Problem solved.... With the clutch basket off one crank can turn freely.... and I moved mine, unknowingly. Why I decided to check it I'll never know, but it was off....set it back where it should have been and it fired on the second kick and sounds wonderful.....

thumper580
Posts: 60
Joined: Wed Jul 12, 2017 3:34 pm
Location: Virginia

Re: Need electrical help...I'm dying here!!!

#8 Post by thumper580 » Sat Oct 14, 2017 6:23 pm

Paulrs wrote:As you pulled the transmission the clutch must have been off. Crazy question but have you double checked the cranks are in phase. The front crank has the rotor on it so would not be effected, not so with the rear crank and one gear tooth out could give the problems you describe.

If above OK try the carbs.

Regards
Paul
You were right....I didn't realize it until I rechecked....I never would have believed it!!!

User avatar
phildu31
Posts: 429
Joined: Tue Jul 19, 2011 7:49 pm
Location: Toulouse France

Re: Need electrical help...I'm dying here!!!

#9 Post by phildu31 » Sun Oct 15, 2017 3:50 am

So, you mean that you swapped plugs, coils, wires, CDI, ... without checking if you had sparks ?

thumper580
Posts: 60
Joined: Wed Jul 12, 2017 3:34 pm
Location: Virginia

Re: Need electrical help...I'm dying here!!!

#10 Post by thumper580 » Sun Oct 15, 2017 11:32 pm

No, I had spark...that's what was driving me crazy..... It missed badly, popped and weak exhaust pressure. The rear cylinders were firing when the pistons were NOT at TDC. The crank turned out of time when I had the clutch basket off...

User avatar
tacky1
Posts: 1248
Joined: Mon Sep 14, 2015 12:30 pm
Location: Bay Area. CA.

Re: Need electrical help...I'm dying here!!!

#11 Post by tacky1 » Sun Oct 15, 2017 11:45 pm

thumper580 wrote:
Paulrs wrote:As you pulled the transmission the clutch must have been off. Crazy question but have you double checked the cranks are in phase. The front crank has the rotor on it so would not be effected, not so with the rear crank and one gear tooth out could give the problems you describe.

If above OK try the carbs.

Regards
Paul
To pull the trans cassette you only take off the two nylon gears and the kick start gear, so both cranks never get changed or touched... These are on the clutch side of the bike.
You have to pull the clutch to get the gearbox out, The clutch main nut is on the end of the gearbox shaft, Are you sure the cranks are timed correctly

EDIT: Sorry, I see you fixed the prob
1985 RZv500
1984 RZ500 Hybrid
1986 RG500 Walter Wolf
1986 RG500 Skoal Bandit
1984 RZ350
1984 RZ350 Hybrid
1981 RD350LC
1981 RD350LC Hybrid
2009 CR500AF Supermoto 250X
2007 CR500AF 250X
1988 YSR50 (2)
1989 VFR750R RC30
1984 GPZ750 Turbo

User avatar
phildu31
Posts: 429
Joined: Tue Jul 19, 2011 7:49 pm
Location: Toulouse France

Re: Need electrical help...I'm dying here!!!

#12 Post by phildu31 » Mon Oct 16, 2017 4:07 am

thumper580 wrote:No, I had spark...that's what was driving me crazy..... It missed badly, popped and weak exhaust pressure. The rear cylinders were firing when the pistons were NOT at TDC. The crank turned out of time when I had the clutch basket off...
Yes, but you didn't say it and we thought that you hadn't sparks on them.
The only thing you said is that you swapped nearly everything in the rear cylinders ignition and, in fact, all that was useless cause ignition was good.
Never mind, you found it.

MK
Posts: 485
Joined: Thu Mar 09, 2006 12:54 pm
Location: Germany
Contact:

Re: Need electrical help...I'm dying here!!!

#13 Post by MK » Mon Oct 16, 2017 3:25 pm

phildu31 wrote:So, you mean that you swapped plugs, coils, wires, CDI, ... without checking if you had sparks ?
Which is completely harmless as the RD500 always fires all four plugs at once. So swapping them all around will always work.
Bye
Martin

Post Reply