1987 RZ350 mis-fire on right cylinder.
Moderator: rztom
- Redline Junkie
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- Location: Halifax, Nova Scotia Canada
1987 RZ350 mis-fire on right cylinder.
Hey Guys
My 87’ seems to be mid-firing on the right cylinder. The bike has fresh crank seals, carb rebuild, new rings etc.. what I have noticed is the right side is slower to warm up when touching the cylinders and once warmed up if I hold the RPM at 4K the left Side provides nice hot, constant exhaust while you hold your hand over the silencer. When you do the same to left side the exhaust seems cool with pop pop pop when firing.
I wonder why it is doing this, changed plugs, coil but have not done compression test yet. Once riding it I can crack it and it would flip over no prob in first gear. Maybe a carburetor issue or low compression?
I will do comp test and report back
Any help would be great
Rob
My 87’ seems to be mid-firing on the right cylinder. The bike has fresh crank seals, carb rebuild, new rings etc.. what I have noticed is the right side is slower to warm up when touching the cylinders and once warmed up if I hold the RPM at 4K the left Side provides nice hot, constant exhaust while you hold your hand over the silencer. When you do the same to left side the exhaust seems cool with pop pop pop when firing.
I wonder why it is doing this, changed plugs, coil but have not done compression test yet. Once riding it I can crack it and it would flip over no prob in first gear. Maybe a carburetor issue or low compression?
I will do comp test and report back
Any help would be great
Rob
Last edited by Redline Junkie on Sun Mar 04, 2018 8:36 pm, edited 1 time in total.
1985 RZ350F being restored now!
1987 RZ350 Stock
1985 RZ350F basket case
1985 RZ500 Stock
1987 RZ350 Stock
1985 RZ350F basket case
1985 RZ500 Stock
Re: 1987 RZ350 mid-fire on right cylinder.
Check the fuel is flowing in that carb. Ive had these bikes do this, they run 'ok enough' on one cylinder especially at idle until you do some research like you have here Rob. Im betting the fuel check valve is the issue.
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid
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81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid
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- Redline Junkie
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Re: 1987 RZ350 mis-fire on right cylinder.
Ok John, so you think it maybe the value on the tank is the issue? I could try it on the prime position if that is the case and see what happen maybe.
1985 RZ350F being restored now!
1987 RZ350 Stock
1985 RZ350F basket case
1985 RZ500 Stock
1987 RZ350 Stock
1985 RZ350F basket case
1985 RZ500 Stock
Re: 1987 RZ350 mis-fire on right cylinder.
no inside the carb, the little pointy one activated by the float. usually if you tap the carb with say a small hammer handle it will unseat and flow fuel. they get sticky with old fuel and lock shut as thats how theyre stored, ie bowls full and so valve shut. a good clean helps and some guys polish them inside the brass part with a q tip in a drill.
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid
Like Watches? www.PloProf.com & www.DeskDivers.com
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid
Like Watches? www.PloProf.com & www.DeskDivers.com
- Redline Junkie
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- Joined: Tue Dec 25, 2012 12:55 pm
- Location: Halifax, Nova Scotia Canada
Re: 1987 RZ350 mis-fire on right cylinder.
Ok, replaced the needle and seat about 2000km ago but I will check to see if it flowing fuel by draining the float bowl while in prime and see if that allows it to flow
1985 RZ350F being restored now!
1987 RZ350 Stock
1985 RZ350F basket case
1985 RZ500 Stock
1987 RZ350 Stock
1985 RZ350F basket case
1985 RZ500 Stock
Re: 1987 RZ350 mis-fire on right cylinder.
Sometimes it will flow when pulled down by all that fuel leaving the bowl, so if you can give it a clean and try that.
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid
Like Watches? www.PloProf.com & www.DeskDivers.com
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid
Like Watches? www.PloProf.com & www.DeskDivers.com
Re: 1987 RZ350 mis-fire on right cylinder.
Additional, check the needle valve re emulsion tube for ovality. Heck swap them over. I've seen them wear before, just a bit ,not round, and they won't run right.
496 Cheetah. TSS PVs, PWK35s, Ignitech, RGV(ish) chassis
Re: 1987 RZ350 mis-fire on right cylinder.
If you worked on that carb, re-check your work.
Otherwise I'd guess a clogged idle jet.
Otherwise I'd guess a clogged idle jet.
Bye
Martin
Martin
- Redline Junkie
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Re: 1987 RZ350 mis-fire on right cylinder.
I think I will try another carb that I have ready for my other 350 and see if there is a improvement.MK wrote:If you worked on that carb, re-check your work.
Otherwise I'd guess a clogged idle jet.
Thanks
1985 RZ350F being restored now!
1987 RZ350 Stock
1985 RZ350F basket case
1985 RZ500 Stock
1987 RZ350 Stock
1985 RZ350F basket case
1985 RZ500 Stock
Re: 1987 RZ350 mis-fire on right cylinder.
I had a one cylinder sometimes firing issue with my 84.
- Redline Junkie
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- Joined: Tue Dec 25, 2012 12:55 pm
- Location: Halifax, Nova Scotia Canada
Re: 1987 RZ350 mis-fire on right cylinder.
I do have another CDI I should try on it after I try another carb first.
1985 RZ350F being restored now!
1987 RZ350 Stock
1985 RZ350F basket case
1985 RZ500 Stock
1987 RZ350 Stock
1985 RZ350F basket case
1985 RZ500 Stock
Re: 1987 RZ350 mis-fire on right cylinder.
Wasted spark setup.
IF one plug Fires the other Must.
Look elsewhere
IF one plug Fires the other Must.
Look elsewhere
Re: 1987 RZ350 mis-fire on right cylinder.
I stand corrected.
Re: 1987 RZ350 mis-fire on right cylinder.
Bad coil?
Red/White US '84, Spec II pipes, Y-boot w/K&N, Fox Shock, Mikuni carbs?