Barely running RU

The place to come to share your technical expertise, or just find out what the little springy thing is that's just pinged out of sight under the work-bench.
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DEVO.RU
Brolly Dolly
Brolly Dolly
Posts: 13
Joined: Thu Feb 04, 2016 7:29 am
Location: Wicklow,Ireland

Barely running RU

Post by DEVO.RU »

Hi all.Im making one last ditch attempt to get my RU running right before i loose the rag and either sell or scrap it.a few years ago it started acting up.not running on cyl no 3 under 3k.i sorted this by removing the resistors in the caps.that solved the problem for a while but it came back with a vengence a few months ago.it would pop and bang while idling.i noticed the caps were arcing off the head on cyl 3&4.replaced the 2 caps with NGK equivalent with their resistors removed.left it sitting for a few months.tried starting it recently,and it wouldn't run over 2k and very rough at that.and would only run with the choke on full.would cut out as soon as the choke was turned off.stripped and cleaned the carbs.made no difference.i also noticed the headers were starting to glow orange after maybe 1-2 minutes of trying to get it to clear.some reconed the timing was out but it cant be as there is no means of adjusting it.for reference its,running a full Acropovic system,stage 3 dynojet,k&n element.and some headwork.many thanks to anyone who can shed a light on this headache.
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YAMAEXUP
Commentary Team
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Location: NW Kent

Post by YAMAEXUP »

When I replaced the piston rings a few years ago on my FZR-R I removed the inlet manifolds from the cylinder head so as to match them to the intake rubbers. There'es an 'O' ring that seals the manifolds to the head & they can crack with age & allow an air leak, which seems to be the symptom when you say that the engine dies as soon as you let the choke off.

What float heights have you set? I set my ones at the suggested height with my Stage 3 DJ kit & it made a difference at partial throttle openings.
Bikes-they're in the blood.


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DEVO.RU
Brolly Dolly
Brolly Dolly
Posts: 13
Joined: Thu Feb 04, 2016 7:29 am
Location: Wicklow,Ireland

Post by DEVO.RU »

Only getting around to look at the bike again lately.the coils,ecu and fuel pump resister have been swapped to no avail.still running badly.even if the carbs were out of balance,surely it would at least run half right.can borrow a set of carbs but they,re not in the best shape due to being on a bike thats laid up a few years.cant imagine the valve tolerances closing up from not being used either
DEVO.RU
Brolly Dolly
Brolly Dolly
Posts: 13
Joined: Thu Feb 04, 2016 7:29 am
Location: Wicklow,Ireland

Post by DEVO.RU »

Il try spraying carb cleaner or thinners near the inlet manifolds and see if it shows up any leaks
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