tech help needed

[Don_bikerider]

Hi Folks
got a fault on my VTR that is driving me crazy it has had
a secondhand engine fitted and i finally got it completed but i have
a weak spark on the rear cylinder the spark is orange but the front
is nice and blue, i swapped the cdi/igniter , the ign amplifier,
coil, both spark plugs, kill switch, checked the resistance on the pickup should be 600-620 K ohms but mine is reading 680 don't think this
is the problem though as the front fires fine.
i have checked the wiring with a multimeter and it all checks out
ok as far as i can see i am hoping to avoid fitting another loom has
anyone any ideas ? need to get this sorted asap,

p.s the parts i fitted are known good as my other VTR runs fine it
is driving me mad need some assistance if anyone can give me any
advice, and no selling the bike is not really an option

Don

[Pete.L]

Have you changed the rear HT lead? It may read okay with a meter but it could be breaking down under load

Pete.l

[Don_bikerider]

Hi
yes i changed the complete coil with the ht lead as well from my other storm which runs fine

Don

[yellafella]

Is the lead tracking anywhere ?

[yellafella]

Err. Another thought. Can you swap the coils and leads over from front to rear, etc ? Does the problem swap over too ?

[Don_bikerider]

hi
no the lead isn't tracking, i changed the complete coil with HT lead from my other storm which is running fine no problems at all, all the exchange parts came off that bike and it runs fine with it's original parts or the ones off the bike that is not sparking correctly i have been checking the wires in the loom to try and make sure nothing is shorting out or broken and all readings seem to be ok just bounce what ideas you have i am ready to try anything beofre i spend any money on a loom which may not sort the problem, just as an aside i have checked all the plugs wires and all the terminals to make sure there is no loose connections really driving me nuts now

Don

[Don_bikerider]

Well folks think i finally cured the problem seems by changing the engine and the rear subframe i messed up the earth contacts on the rear wiring loom the earth goes from the battery to the engine then the earth comes through the engine to the frame along the frame to the rear rectifier which has the earth connection for the rear section of the loom so as a last ditch attempt before installing another loom i wired a new earth to the coil body problem solved so consequently i have added a dedicated earth wire for the rear wiring from the battery negative, problem solved so anyone having any similar problems may want to do this first may help

Don a very happy firestorm Owner

[puppy]

Hi Don, how did the op on the hand go?

Have you fitted the Akra yet, and if so what do you think of it?

John

[sirch345]

Well folks think i finally cured the problem seems by changing the engine and the rear subframe i messed up the earth contacts on the rear wiring loom the earth goes from the battery to the engine then the earth comes through the engine to the frame along the frame to the rear rectifier which has the earth connection for the rear section of the loom so as a last ditch attempt before installing another loom i wired a new earth to the coil body problem solved so consequently i have added a dedicated earth wire for the rear wiring from the battery negative, problem solved so anyone having any similar problems may want to do this first may help

Don a very happy firestorm Owner

I'm pleased to hear you think you've sorted the problem

Chris.

[Don_bikerider]

Hi John the Op went well seem to be gaining more feeling every day got the Akra fitted but not set the bike up yet sounds lovely it is now on my other VTR as i ended up buying another when i couldn't get the first one running correctly the new one is slightly higher mileage but has new CCT's fitted so should be a good investment it only has 18,000 miles on it but i thought the cct's should be changed after my 12,000 mile one went pop i haven't set the old one up but seems to be running fine now awaiting some Std cans from Ebay purchase i am restoring the first one to near std condition except braided Hoses and K+N filter, carbon effect hugger it will be up for sale once i get it done as i can't justify keeping both bikes as i also have a vfr750 and a Scorpa trials Bike so i will let you all know when i decide what i am doing

Don

[puppy]

Hi John the Op went well seem to be gaining more feeling every day got the Akra fitted but not set the bike up yet sounds lovely it is now on my other VTR as i ended up buying another when i couldn't get the first one running correctly the new one is slightly higher mileage but has new CCT's fitted so should be a good investment it only has 18,000 miles on it but i thought the cct's should be changed after my 12,000 mile one went pop i haven't set the old one up but seems to be running fine now awaiting some Std cans from Ebay purchase i am restoring the first one to near std condition except braided Hoses and K+N filter, carbon effect hugger it will be up for sale once i get it done as i can't justify keeping both bikes as i also have a vfr750 and a Scorpa trials Bike so i will let you all know when i decide what i am doing

Don

Good to hear the Op went well, let me know what you think of the Akra when the bike is up and running.

[Don_bikerider]

Well seems i didn't sort the problem after all still has a weak spark on the rear cylinder need some ideas here folks Just to recap i have changed everything with the exception of the wiring loom and the ign pickup and the coil pickup seems unlikely as the front cylinder runs fine the rear cylinder is firing just with a very weak spark i:e orange instead of blue i have swaaped the plugs over front to rear with no difference the rear coil complete with lead has been swapped from my other storm both black boxes have been swapped, really could do with sorting this problem out so if anyone has any ideas i would appreciate it, or if anyone has a secondhand loom or pickup lying about i would gladly pay to eliminate these as the problems

Don 07973762832