nopokewithoutsmoke Posted September 29, 2018 Posted September 29, 2018 Hello chaps and chapesses. Just joined up and I really hope you can help with my 600 SRAD that's running on 3 cylinders... I 've posted on say what now!?.com but it's very quiet there... here's the story so far... 1.) Any help and advice appreciated... 600 SRAD, been in storage for 3 years with all fluids drained. History/issues prior to this unknown. With fresh fuel, oil, water and battery it runs but only on 3 cylinders. It idles at 1200rpm with the choke off, but no.1 header doesn't get hot. With a small amount of throttle the revs will rise to 3000rpm but hang there before slowly dropping back down. Plugs are new CR8E's to help avoid fouling while it's idling. I've swapped coils over between cylinders but no.1 stays cold. I haven't touched the carbs. Battery voltage is 13.1V and rises to 14.6V with engine idling. What would you do next? 2.) Checked continuity in the green wire from the ECU to the coil on no.1 cylinder, and the white/purple wire between 1 and 4. Both checked out ok. Swapped spark plugs between 1 and 2. No change in how it runs. Carb inspection and compression test next... Advice and suggestions welcome! Quote
Askamaskinservice Posted September 29, 2018 Posted September 29, 2018 1&4, 2&3 share coil. so you have to change 1 and 4 and see if you will move the fault to number 4 cylinder. Then the coil is gone. Quote
Gixer1460 Posted September 29, 2018 Posted September 29, 2018 34 minutes ago, Askamaskinservice said: 1&4, 2&3 share coil. so you have to change 1 and 4 and see if you will move the fault to number 4 cylinder. Then the coil is gone. OP said he's done that - #1 stayed cold therefore it can only be a duff plug (possible) or lead (unlikely) or #1 carb (highly likely based on period of inactivity) Carbs never drain completely so crud in jets is my bet! Quote
Captain Chaos Posted September 29, 2018 Posted September 29, 2018 1 hour ago, Askamaskinservice said: 1&4, 2&3 share coil. SRAD 600 has coil on plug thingies. Quote
nopokewithoutsmoke Posted September 29, 2018 Author Posted September 29, 2018 Thanks for the quick responses. It does indeed have coil on plug thingies, one for each cylinder. I swapped them over, no change. I swapped plugs over, no change. i didn't want to get into the carbs until I'd checked the ignition side. Rather be methodical than chuck a load of carb cleaner in and hope for the best... I think Gixer1460 is going to be right about them being full of crud. Quote
nopokewithoutsmoke Posted September 30, 2018 Author Posted September 30, 2018 Made some progress. Carbs came apart relatively easily with no evidence of previous bodgery. Was expecting more crud in there but the bowls were quite clean. The pilot jets however needed a good soak and a poke through with nylon wire. I didn't change any of the settings, just reassembled the carbs after cleaning, and it now idles happily on all 4 cylinders! Throttle response is crap and it's reluctant to rev but it's a starting point... 1 Quote
nopokewithoutsmoke Posted October 2, 2018 Author Posted October 2, 2018 After running it to get it hot a couple of times with lots of mixed rev throttle blipping, throttle response has definitely improved. Revs were hanging a fair bit though so checked the pilot screws and they were all at 2 and 1/2 turns out. I adjusted them to 3 out on the outer cylinders and 2 and 3/4 on the middle cylinders (as per Haynes). Definitely better again but revs still take too long to drop from 3k to idle. What next do you think??? Quote
Havoc Posted October 2, 2018 Posted October 2, 2018 (edited) Next I would look for an air leak between carbs and head, can often be the cause of reluctant return to tickover. Cracked inlet rubber or missing balance plugs.. Edited October 2, 2018 by Havoc Quote
nopokewithoutsmoke Posted October 3, 2018 Author Posted October 3, 2018 19 hours ago, Havoc said: Next I would look for an air leak between carbs and head, can often be the cause of reluctant return to tickover. Cracked inlet rubber or missing balance plugs.. Thanks for the input.Visual checks and spraying wd40 around the rubbers didn't make any difference. Maybe the revs aren't hanging so badly... I did adjust the pilot screws again so they're now at 3.25 turns out. Seems a little better but difficult to tell. I think I'm just going to get the bike ready for an Mot and see what it's like after a bit of use on the road. I've still got valve clearances and carb balancing to do, but they can wait. Quote
Swiss Toni Posted October 3, 2018 Posted October 3, 2018 Try running some YamahaCarbCleaner thru' the carbs. Works wonders. Follow the destructions to the letter. Has been known to fettle carbs after 15 yr lay ups! Try it. 1 Quote
clivegto Posted October 3, 2018 Posted October 3, 2018 Unbalanced carbs can make the revs hang. Quote
nopokewithoutsmoke Posted October 4, 2018 Author Posted October 4, 2018 I might just try some of that Yamaha Carb Cleaner, and carb balancing is definitely on the 'to do' list. Thanks guys Quote
Swiss Toni Posted October 4, 2018 Posted October 4, 2018 Make sure you get the old stock type with the red label, rather than the 'new improved' shit with the yellow label. Quote
Fula28 Posted October 6, 2018 Posted October 6, 2018 Have done few sets of these carbs, I prefer Profi fuel max additive, this stuff is truly amazing and cleares those hard to reach places, Others cannot ! Try it and report back sure this will help your slow running issues for a bike that stood a while! Ethonol in our fuel ruins carb orings and float needle seats , and most carbed bikes can be effected if not run regular enough. Quote
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