Strange Ignition Problem!

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Jizzmeister
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Posts: 10
Joined: Mon Dec 14, 2009 6:46 pm
Bike owned: FZR 400 1986 ZXR 400 1992, CBR

Strange Ignition Problem!

Post by Jizzmeister » Thu Jul 08, 2010 10:05 pm

Hi guys, if anyone can shed some light on this problem I would be very grateful.

I own an FZR 400 genesis (1986) with approximately 60,000km on the clock. About a month ago I noticed the odd backfire sound perhaps once everytime I took it out, and over time it got more and more frequent.

Suddenly last week the engine started sounding terrible somewhat like a lawnmower or old single/twin cylinder bike. I stopped riding it but have failed to find the problem. Only the exhausts for cylinders 2 & 3 were getting hot.

I have checked the resistance of the primary and secondary coils in BOTH coilpacks, they were found to be the same and within manufacturers specs. I had checked sparkplugs and they looked fine. I took out the first and the four spark plug leads and connected them to plugs and could see no sparks when turning over the engine with the starter motor.

Finally I bought a 2nd hand CDI with the same serial etc fitted it and the situation was no different, finally i swapped over the 'low tension' connectors to each coilpack and the bike would not start at all :down: .

Could it possibly be one of the 2 relays wired in with the CDI?? or is it more likely to be the coilpacks? (i have another one for cylinders 1 &4 due in the post.

Many thanks in advance! :pray:

Evilchicken0
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Bike owned: Bimota SB6 Yamaha FZR 3TJ x2
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Re: Strange Ignition Problem!

Post by Evilchicken0 » Thu Jul 08, 2010 10:56 pm

because it's on 1+4 Changing the coils would seem like the most obvious thing.

While you wait for the coil you could clean the carbs and renew the filter to be certain.

One other thing - have a look at the wires for the side stand cut out and bridge them awhere they join the loom. I don't think it's that but it's just something to check.

Q007
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Posts: 75
Joined: Fri May 30, 2008 10:34 pm
Bike owned: FZR 400 1wg 1986 FZR 600r 1995
Location: WEYMOUTH DORSET

Re: Strange Ignition Problem!

Post by Q007 » Sat Jul 10, 2010 2:40 pm

Evilchicken0 wrote:because it's on 1+4 Changing the coils would seem like the most obvious thing.

While you wait for the coil you could clean the carbs and renew the filter to be certain.

One other thing - have a look at the wires for the side stand cut out and bridge them awhere they join the loom. I don't think it's that but it's just something to check.

The 1986 genesis model doesn't have a side stand switch or at least the grey import model doesn't.
Trust me I know coz I'm a bugger for pulling away n hearing a grinding noise as i have to turn left outta my drive..lol.

Q007
Settled in member
Posts: 75
Joined: Fri May 30, 2008 10:34 pm
Bike owned: FZR 400 1wg 1986 FZR 600r 1995
Location: WEYMOUTH DORSET

Re: Strange Ignition Problem!

Post by Q007 » Sat Jul 10, 2010 2:47 pm

Jizzmeister wrote:Hi guys, if anyone can shed some light on this problem I would be very grateful.

I own an FZR 400 genesis (1986) with approximately 60,000km on the clock. About a month ago I noticed the odd backfire sound perhaps once everytime I took it out, and over time it got more and more frequent.

Suddenly last week the engine started sounding terrible somewhat like a lawnmower or old single/twin cylinder bike. I stopped riding it but have failed to find the problem. Only the exhausts for cylinders 2 & 3 were getting hot.

I have checked the resistance of the primary and secondary coils in BOTH coilpacks, they were found to be the same and within manufacturers specs. I had checked sparkplugs and they looked fine. I took out the first and the four spark plug leads and connected them to plugs and could see no sparks when turning over the engine with the starter motor.

Finally I bought a 2nd hand CDI with the same serial etc fitted it and the situation was no different, finally i swapped over the 'low tension' connectors to each coilpack and the bike would not start at all :down: .

Could it possibly be one of the 2 relays wired in with the CDI?? or is it more likely to be the coilpacks? (i have another one for cylinders 1 &4 due in the post.

Many thanks in advance! :pray:


Could be just that the coilpack for 1 & 4 isn't getting power to it, take off the 2 spade connectors on the coil and check the voltage there. that's if the relays check out to be o.k. a chaffe in the wire could be causing the problem as you did describe it got progressively worse over time.

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