1973 k2 Honda 500 carb problems (Sorted now, was coil wiring issue, not carbs)

[Johnwebley]

is this kit any good,

 needle,jets ,"O" rings,etc,

 all for under £20 + p&p + VAT

 http://www.davidsilverspares.co.uk/CB500K1-FOUR-1972/part_61450/

[Trigger]

is this kit any good,

 needle,jets ,"O" rings,etc,

 all for under £20 + p&p + VAT

 http://www.davidsilverspares.co.uk/CB500K1-FOUR-1972/part_61450/

That works out, all for under £100 John. These are cheaper >> http://www.ebay.co.uk/itm/161492636759?_trksid=p2057872.m2749.l2648&ssPageName=STRK%3AMEBIDX%3AIT

[Johnwebley]

is this kit any good,

 needle,jets ,"O" rings,etc,

 all for under £20 + p&p + VAT

 http://www.davidsilverspares.co.uk/CB500K1-FOUR-1972/part_61450/

That works out, all for under £100 John. These are cheaper >> http://www.ebay.co.uk/itm/161492636759?_trksid=p2057872.m2749.l2648&ssPageName=STRK%3AMEBIDX%3AIT

thanks Trigger,at present mine are behaving (fingers crossed) but will try to remember for the future,I wonder if the Thread starter ; Jon Stead,will find it interesting?

[Trigger]

He said that he had the carbs done John but, i am wondering if they just cleaned the internals ?

[jon stead]

^^ Hi lads, yes saw your posts about spares kits. When teh carbs were rebuilt it was all new David Silver parts inside. The carbs are going back to the overhauler when I get home for him to have another look at now that there are some known faults and feedback. Hopefully he can make them work.

[Johnwebley]

recently I have noticed the carb setting are more critical,


years ago,it would run with the airscrews open 2 turns,
now ,it is only 1 turn,and 1/8 either way makes a difference,also,what is the state of the air filter ??

[JamesH]

Also worth checking for any burrs / unrefined castings on the float pin struts - just a bit of fine wet / dry to clean them up can often make the difference.

[jon stead]

Thanks for all the tips, much appreciated

[Trigger]

fitted a whole new carb kit and still have the same problem as Jon Stead. Rev's drop after a while but, as soon as you rev up it will not drop lower than 3,000 rpm. Another head scratcher and not sure which way to go.

[Trigger]

Try removing the cables Graham and blipping the throttle by using your hand on the butterfly. If it doesn't do it, then the problems the way the cables are routed or the way they are connected, sometimes easy not to leave enough slack in the cable or the cables sticking.

Cheers Oddjob. Already gone down that route  Even put a electronic Vacuum mate on the carbs so, the balance is perfect.

[Trigger]

You checked the throttle stop screw on the butterfly? it's an eccentric cam arrangement and if it's out it will hold the throttle open even with no cables attached.

Will go through it again tomorrow. I can get it to tick over at 800 rpm but, twist the throttle to 7,000 rpm and it will only return to 3,000 rpm and after a while will return to 800 rpm or drop off completely.

[deltarider]

Possible air leaks between carbs and head? O-rings between head and intake manifold are always suspect.

[jon stead]

^^^thanks Delt Rider.

Got the bike running today but it will not tick over. Rides ok ish, apart from a horrendous front wheel wobble and once warmed up is a pig to restart.

When I get more time I will check for air leaks as suggested. At the moment I'm just glad I actually got a rude out if it. Gears work, brakes work, no engine oil leaks, so just this wheel wobble and tick over and jobs a good'un.

Thanks everybody for your support and suggestions, much appreciated.

[mike the bike]

Have you checked the idle jets/emulsion tubes?

[matthewmosse]

Outside chance here, but the bit about being a pig to restart once hot reminded me of my first cb550, it had most of the same symptoms as I recall, it was down on compression thanks to the rings being mia on top of pistons.... If you don't know the history of the inside of the engine, it might be worth just checking compression. Mine still pulled a ton with the engine like that, pretty well inpossible to start once hot, tickover a pain to get anywhere near right. Valve clearences were often needing adjustment too. Worth a quick check in my books.