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wooders750

Joined:

Nov 11

Posts: 1

wooders750 says:

cbx 750

heelo there, i've just got an 86 reg cbx 750, my problem is that when i try to ride it after letting it warm up the middle two cylinders splutter then cut out , i give it two mins and it is fine untill i try to ride it. HELP is it poss the coils or leads, or do i have to pull the carbs apart? please help as i bought this as a " good bike " and when i got it delivered to my place and ran it up i found four blowing head to exhausts and a sump that has dumped half it's oil over my drive. THANKS DAVE FROM Bournemouth, Really need help. Wooders.:upset::mad:

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  • Posted 3 years ago (24 November 2011 16:39)

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robsot

Joined:

Feb 10

Posts: 871

robsot says:

..

Have you checked HT cap connections?? are those cylinders running off the same coil?? i dont know this bike.. bet someone on here will though!

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jaffa90

Joined:

Mar 09

Posts: 8820

jaffa90 says:

good bike?

Get your money back.If you have two coils one for 1/4 cyl and one for 2/3cyl.I would do a compression test first,then valve clearances (if not hydraulic) and a full service.

Oh and welcome with a dog maybe.:shock: 

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MarcusMarsh

Joined:

Aug 09

Posts: 2693

MarcusMarsh says:

CBX750

I always liked those.  The engine, in theorey, was deemed to be low maintenance with hydraulic valves and a camchain tensioner that actually worked. 

Sorry to say it but it sounds as if your example hasn't been particularly well looked-after.  They are mechanically robust though so I hope it's nothing major.  Have a look at the coils as suggested by Jaffa and then check the carbs.   

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kcmc

Joined:

Jan 08

Posts: 7178

kcmc says:

Honda CBX 750 1986

Hi Wooders750 and welcome to the sit:smile

Unfortunately it sounds like you have bought a bit of a pig in a poke?but you must remember the bike is now 25 years old(quarter of a century)so things do start to go wrong,its inevitable.Are you sure its the two middle cylinders and not one?.If you decide to keep the bike,then check the coil for 2and 3 cylinder,the HT leads,plug caps,if the problem isn't there then check the twin pulse pick ups as i know this to be one of the few faults this bike had back in its day.Also check the plug connector from the main loom to the coils(check for corrosion and continuity)as it is a separate piece of loom.Drain the carb float bowls into a clean bowl to seen if there is any water or debris in there?if there is there could be water in the fuel tank as well.Check the vacuum pipe from the fuel tap is fitted and not split or leaking.Check the sump nut hasn't been over tightened and stripped the thread or worse split the aluminium around the sump,if not replace the sump nut crush washer or fit a copper washer. Good Luck

KCMC:tongue:

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fj1200alf

Joined:

Dec 11

Posts: 4

fj1200alf says:

CBX 750

 have myself the same problem. If it is not the coil, it could be dirty carbs. The debriss stuck the float bowl valves The check is easy: put an auxiliary deposit (a sringe, i.e.) attached to the fuel hose. It is not necessary start the bike. If petrol start to overflow, the valves are collapsed with rubbish Clean carefully with compressed air the dismounted carbs. If not, your nightmare will continue Visit my web for more info www.fj1200.info or join to the friendly teamrc17 mail list http://www.teamrc17.net/ Regards

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