Honda-SOHC
SOHC.co.uk Forums => CB500/550 => Topic started by: Roxy John on March 27, 2023, 11:28:19 AM
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Morning all, it's been a while since I last posted so I thought I would update after the first proper ride out after a lot of tinkering.
Saturday was pretty much the first dry weekend day for ages so I took the CB for a shake-down trip - approx 30 miles around various lanes and a bit of dual carriageway. When I first got the bike in January it wasn't running well and was very reluctant to start. Fearing a blockage in carbs after I cleaned the tank, I stripped the carbs, ran them through the ultrasonic cleaner and re-built with Julie's o-ring kit (thanks Julie - excellent service and very good price!). The floats were all over the place so set them all to 22mm and vacuum balanced when all back together.
I also fitted 4 new plugs, new battery, changed oil & filter and checked & adjusted valve clearances.
The bike still doesn't want to start easily but once fired-up, settles to a nice even idle. However, during the ride on Saturday, when pulling up to junctions and waiting at traffic lights, the idle hung around at 2000 (ish) rpm before settling down and felt like it would die at any moment. I pulled on to petrol station forecourt and it did indeed die. It fired-up again having filled up and while riding, responds well to the throttle, pulling very nicely throughout the rev range with no hesitation well up to 8000 ish - any ideas why it may struggle at idle? I wondered about an air-leak but have sprayed carb-cleaner over all the inlet rubbers and no change in revs. It has the DSS electronic ignition which is set correctly.
Also, rather annoyingly, I lost the generator cover plate during the ride - I can get one from DSS but £90.... anyone have a spare or are they so rare that the price is the price?
Cheers, Phil
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Sounds like an air leak on the induction side somewhere - check between carbs & head - another member here had a similar issue recently.
As regards changes in idle speed I've read somewhere that it's the nature of the beast on these older design of carbs?
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Hanging idle is nearly always attributable to the pilot jets and/or pilot drillings. I put my carbs through the U.S. cleaner several times without success and eventually had to use aerosol carb cleaner in the pilot jet ways, sequentiality blocking the three points of entry/exit. I used STP carb cleaner, two tins of it. I then heated the pilot jets to ‘ash’ any fuel deposits and then pushed through the #40 jets with #38 probe. It worked, the hanging idle disappeared and the throttle response returned to factory standards.
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Hanging idle is nearly always attributable to the pilot jets and/or pilot drillings. I put my carbs through the U.S. cleaner several times without success and eventually had to use aerosol carb cleaner in the pilot jet ways, sequentiality blocking the three points of entry/exit. I used STP carb cleaner, two tins of it. I then heated the pilot jets to ‘ash’ any fuel deposits and then pushed through the #40 jets with #38 probe. It worked, the hanging idle disappeared and the throttle response returned to factory standards.
Thank you for that - sounds like that's what I need to do then. I've got plenty of STP carb cleaner so will take it all to bits again. Not a job I relish but has to be done! Thanks for your help 👍👍
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https://www.ebay.co.uk/itm/354154761826?hash=item527544ce62:g:57gAAOSwt~9iyFMV&amdata=enc%3AAQAHAAAA0Ihxg7lWlgyHaFk4hgMBd%2BjxT5faV3GbWHzg8ElFWifVm%2BUJR8q8q0c4zW5ve9JV2HoLFoPYvsmO%2FSNgG2ikl0KZ0HfWsQFCq9TrifVJYqamNGDQi%2F6lWRrr3FtaohdoBt%2Fzbu9vpo1PLEtSAcxG9JhbsHKNE2rN%2BL9S9%2Faf4S9dlGPmU2wCabTAwQodm4ExuskN%2BQdT4Ov6r4F3CnO1TVTG%2Bzo7xN%2Be3tkU8RsyTOgGC0buzD7GwM%2BaV%2FYMs4ykw09XN%2B9lU6RxksCYyoh2Im8%3D%7Ctkp%3ABk9SR5Tt_rvkYQ
Or
https://www.ebay.co.uk/itm/203778550584?hash=item2f7225eb38:g:eLIAAOSw-ldh0aZV&amdata=enc%3AAQAHAAAAwMRnPMXyr1txyl8SX8U5Fla5zb3k4%2Bt7D75c3CMHMx5JX6tiApmxWi%2BhNyLwb29E46T6vp4k6v9FjkrZA36nplnP4H%2Fyp6IQUEuC%2BJFcJnCy9N28IWC5aiGTYPWxcc0kn2cpiifXyVf2v5ZiRIBSGOG%2FuoY5T8sytXwn7LAjByEvjmV5Fk%2FgbE6LYsj%2FKa1efCUmg5cQbgED7O84knuFO%2FjhGq0BCDiNWala1axa2NozNx8J0bvk9TNW%2F0kOFOdT6g%3D%3D%7Ctkp%3ABk9SR47ijbzkYQ
I bought one from Shire Bikes, the seller above, last year and it was £46 which I thought was dear then.
The cover is held on my 3 small spring clips which grip the pegs as they are inserted, they are only mild steel and tend to rust to bits, that causes them to lose grip and the cover falls off. Buy new ones or you'll lose the new cover as well, cover them in grease before fitting to protect them as well.
The other alternative is to fit the generator over off a 550 which looks the same except the Honda logo is actually part of the cover and you can't lose it. The only downside is you can see the 3 screws holding the field coil in place. Finding one in decent nick is the hard part.
Like this
https://www.ebay.co.uk/itm/354463125979?hash=item5287a611db:g:Mo4AAOSwnw5joE48&amdata=enc%3AAQAHAAAA0JnuH4kpS0aBZfxSPo4YVeHdJzOr9vskzZwSJYOurfuFtU5SDkal6%2BFlpNVquh7iu3wrKIO58ct02GgxkXojng2owRkUYgVgI17hOjl%2FDNnPCSONM5pp6mQcvScLBRASXS%2FcvaLBnS1YVJH7DtRYcgg%2FOP70c9%2BV4T2vQN3u0Qm%2BWGxh%2F5lrxF91OaS5VOLMytF3lFBRRvA9rQVSe3ps9UQGD3stdcML0F8QJnE3UwJqDSA%2BCoCO8XMDRemS8HVQgN5O9lpsA0SBRzuY3uynB5I%3D%7Ctkp%3ABk9SR6KnurzkYQ
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https://www.ebay.co.uk/itm/354154761826?hash=item527544ce62:g:57gAAOSwt~9iyFMV&amdata=enc%3AAQAHAAAA0Ihxg7lWlgyHaFk4hgMBd%2BjxT5faV3GbWHzg8ElFWifVm%2BUJR8q8q0c4zW5ve9JV2HoLFoPYvsmO%2FSNgG2ikl0KZ0HfWsQFCq9TrifVJYqamNGDQi%2F6lWRrr3FtaohdoBt%2Fzbu9vpo1PLEtSAcxG9JhbsHKNE2rN%2BL9S9%2Faf4S9dlGPmU2wCabTAwQodm4ExuskN%2BQdT4Ov6r4F3CnO1TVTG%2Bzo7xN%2Be3tkU8RsyTOgGC0buzD7GwM%2BaV%2FYMs4ykw09XN%2B9lU6RxksCYyoh2Im8%3D%7Ctkp%3ABk9SR5Tt_rvkYQ
Or
https://www.ebay.co.uk/itm/203778550584?hash=item2f7225eb38:g:eLIAAOSw-ldh0aZV&amdata=enc%3AAQAHAAAAwMRnPMXyr1txyl8SX8U5Fla5zb3k4%2Bt7D75c3CMHMx5JX6tiApmxWi%2BhNyLwb29E46T6vp4k6v9FjkrZA36nplnP4H%2Fyp6IQUEuC%2BJFcJnCy9N28IWC5aiGTYPWxcc0kn2cpiifXyVf2v5ZiRIBSGOG%2FuoY5T8sytXwn7LAjByEvjmV5Fk%2FgbE6LYsj%2FKa1efCUmg5cQbgED7O84knuFO%2FjhGq0BCDiNWala1axa2NozNx8J0bvk9TNW%2F0kOFOdT6g%3D%3D%7Ctkp%3ABk9SR47ijbzkYQ
I bought one from Shire Bikes, the seller above, last year and it was £46 which I thought was dear then.
The cover is held on my 3 small spring clips which grip the pegs as they are inserted, they are only mild steel and tend to rust to bits, that causes them to lose grip and the cover falls off. Buy new ones or you'll lose the new cover as well, cover them in grease before fitting to protect them as well.
The other alternative is to fit the generator over off a 550 which looks the same except the Honda logo is actually part of the cover and you can't lose it. The only downside is you can see the 3 screws holding the field coil in place. Finding one in decent nick is the hard part.
Like this
https://www.ebay.co.uk/itm/354463125979?hash=item5287a611db:g:Mo4AAOSwnw5joE48&amdata=enc%3AAQAHAAAA0JnuH4kpS0aBZfxSPo4YVeHdJzOr9vskzZwSJYOurfuFtU5SDkal6%2BFlpNVquh7iu3wrKIO58ct02GgxkXojng2owRkUYgVgI17hOjl%2FDNnPCSONM5pp6mQcvScLBRASXS%2FcvaLBnS1YVJH7DtRYcgg%2FOP70c9%2BV4T2vQN3u0Qm%2BWGxh%2F5lrxF91OaS5VOLMytF3lFBRRvA9rQVSe3ps9UQGD3stdcML0F8QJnE3UwJqDSA%2BCoCO8XMDRemS8HVQgN5O9lpsA0SBRzuY3uynB5I%3D%7Ctkp%3ABk9SR6KnurzkYQ
Ah, many thanks for that Oddjob, much appreciated. I'll go with the Shire Bikes one 👍👍
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If you need the clips as well it may be cheaper to buy from DS, work it out first before buying.
Clips are part number 11633-323-000, £3.82 each at DS.
The cover looks new in the pic, whoever fitted it probably didn't know about the clips rotting. Shame, you tried looking for it?
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BTW, if you take the carbs off replace the orings in the manifolds, they can go flat and stop sealing allowing the joint to suck air in. Same part as the tappet cover orings BTW 91302-001-020
Julie sells them.
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Here you go, a lot cheaper than Honda. https://www.ebay.co.uk/itm/165957568364?hash=item26a3d7876c:g:0fsAAOSwvTpZ5j~M&amdata=enc%3AAQAHAAAA0KsHAoy2rSkZ8J3UhtQ%2B2cXkY0tU85bMpiigi3CsagLRUchewMb3z1NmJ0GtL5hMxsbH7Ni0nWcy5ziWS0nA%2Fo4Z2ci02vXXDgNBDlJKWWEvtTSp%2BONX2ImGc8pKw6fH7Mk3wJEd2DXiHhOLS%2BmNQQIOsfHYHRQwvnBIOrBcK4Z1dMgjeYDrgj5ZOp%2BatX7YCDX7oHbNVDggBS5l3qzvqM%2BzT3kUB5EKEuLq2SKltmWMYAtMj%2FtgNWaYILWZpj7nGYs4i9UssK7NWgP8r8fS5Eo%3D%7Ctkp%3ABk9SR_i_k8DkYQ
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Thank you Oddjob & Julie - at the very real risk of looking like an idiot, when I took the carbs off, I didn't find any o-rings like that.....🤔🤔. I'm guessing that they sit inside the carb to inlet rubber boot jobbies and seal between face of carb stub and cylinder head?
Regarding the generator cover - it was a new one, fitted by previous owner. :-[ Must have shaken loose when I was hurrying along a bit on Saturday. Coincidentally I had to re-trace part of the route in the car later in the day and had a cursory hunt as I drove along but no luck.
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Those O rings are between the alloy manifold and head.
Those covers roll well and get covered in invisiblum!
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Ah, thanks Bryan - I didn't take the manifolds off last time. I've ordered the kit from Julie so will have a play this weekend.👍👍
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Also, rather annoyingly, I lost the generator cover plate during the ride - I can get one from DSS but £90.... anyone have a spare or are they so rare that the price is the price?
Did you try to find it? For £90 you can buy lots of fuel for your search ;)
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I was out for about an hour covering verge-lined lanes and a bit of dual carriageway - I'll keep my eyes open but reckon the chances of finding it are pretty slim... If it's visible from the car it's likely to be scuffed-up pretty bad and if it's rolled into the verge I've got no hope! Will probably just have to put it down as "one of those things"..... :-(
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I lost a sidecover once (long ago, last century) and found it some 2 weeks later, other side of the road, with just some little scratches, so it CAN happen!
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I lost the side-panel from my RD350 on the Cat and Fiddle in 1994... worth a fortune now...if anyone spots it...☺
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This conversation reminded me of how sometimes the impossible to find can be found.
Sometime around 1995 my late Mum returned home after shopping in Derby Town Centre - she was very distressed having lost the stone out of her Diamond Solitaire Ring.
I said it would have most likely fallen out whilst opening or closing the car door or shopping at Superdrug. I searched the driveway then went to the car park in town checking the parking bay - no luck.
On the off chance we went to Superdrug on Victoria Street and spoke to the manager who agreed to get the floor swept as they were about to close. This lovely young Saturday lad duly swept the first aisle where he found what he thought was a glass chipping - it was the stone!
My Mum was ecstatic & gave the young man a twenty pound note as a reward - the funny part was my late Dad was not happy as he wanted the potential Insurance payout. lol
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I lost the side-panel from my RD350 on the Cat and Fiddle in 1994... worth a fortune now...if anyone spots it...☺
I'll bet the fellas strimming the grass at the side of the road found that Andy, which reminds me, I had a mate who worked on the parks back in the 70s, he was about 17 or so back then, he was strimming some grass at an all girls school one summers day, with him still being very young etc the girls were all ogling him so he was kinda showing off a little, he was so busy eyeing up all these girls he wasn't looking at what he was strimming and his strimmer went through a huge pile of dog shit which was hiding in the grass. It flicked it up in the air and covered his face in shite, I remember falling over laughing when he told me, the girls were in hysterics and he said all I could think at the time was "DON'T LICK YOUR LIPS"
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I once watched my brother do exactly the same thing in tall grass except it went up his nose, his mouth and all over his teeth, tash, the lot ;D ;D ;D ;D ;D ;D ;D ;D ;D.
I could hardly breathe for rolling around laughing as he was gagging and throwing up at the same time. He put the hose up his beak and everything trying to get the stench away. His mrs wouldnt kiss him for a week ;D ;D ;D
I didnt say a word to anybody obviously...............apart from anyone he knew that is 8) 8)
For weeks afterwards, at home, one of us would just amble passed him and say.........." Can anyone smell s**t, no? just Matt then" which was then followed by him legging after us and one of us getting a smack. It was so worth it ;D
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When a local farmer was emptying my parents septic tank there was a brief halt due to a blockage on the suction side. Said farmer switched the hoses to back flow with some water. Hose flipped out of the tank covering my Dad in the waste. My Mum hosed him off in the garden throwing his clothing in the bin. Pre mobile phones so no pictures - how we laughed when I was told later that day what had happened. Happy days when farmers could spread the contents on his fields as free fertilizer.
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Morning all, just another thought on the annoying hanging idle - when I dismantled the carbs, the air/fuel mixture screws were between 1.75 & 2 turns out. When I rebuilt, I installed all screws to 1 turn out as per factory spec. I've been having a read on t'internet and fancy having a play with these screws before stripping everything down again, however, I'm not sure what would be the best procedure to adopt when adjusting - do I set idle to 1000ish and then turn screws in/out and see what happens? Or set to 2000ish and do the same?
I've got the vacuum balancing gauges so can ensure all in sync but I'm not experienced with setting up carbs and don't want fiddling with one thing to cause more problems than I already have! Any advice appreciated.
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The 'pilot jets' you are refereing to, I'm assuming you mean air/ fuel mixture screws on the outside of the carbs?
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The 'pilot jets' you are refereing to, I'm assuming you mean air/ fuel mixture screws on the outside of the carbs?
Yes Julie, those are the ones I meant - I've revised the wording so it makes sense!
(Thank you for the o-rings and the note :D )