Guest vf500n00b Posted June 24, 2013 Share Posted June 24, 2013 my vf500 isnt firing on all cylinders. I checked: Plugs and leads, all fine sparks are made on all plugs. Fuel smell is quite prominent so it seems that timing maybe off on that cylinder What should i check if plugs and leads are fine? Link to comment Share on other sites More sharing options...
Member Contributer YoshiHNS Posted June 24, 2013 Member Contributer Share Posted June 24, 2013 Do you know which cylinder isn't firing? Have you cleaned the carbs out? Have you done a compression test or a leak-down test? Did any of your plugs look wet/rich? Have you done a valve check? It's not likely at all that the timing is off on one cylinder. Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted June 24, 2013 Member Contributer Share Posted June 24, 2013 or coil !!!!! Swap coil packs and see if the problem follow's the coil. Link to comment Share on other sites More sharing options...
timmythecop Posted June 24, 2013 Share Posted June 24, 2013 I bet the front right (as you sit on bike) jug isnt firing. If so, I say it is fuel starvation. Link to comment Share on other sites More sharing options...
Guest Posted July 4, 2013 Share Posted July 4, 2013 I was first convinced that the rear-right cylinder wasnt firing. However on second inspection: 1. I noticed that the front right exhaust wasnt seated properly on the port, I have applied some exhaust sealer now, however the thread on the bold was stripped aswell. So the front right exhaust wasnt giving full back-pressure. I will check this again in a while. 2. I have a feeling the timing is off on the rear cam chain (may have skipped a tooth) - but the weird thing is that i didnt race the engine from between when the engine was fine and until I noticed this problem. Possibly a tensioner issue? Bike sounds like a HARLEY currently only got the main 4-2 exhaust box on (no mufflerrs) So to answer you question: the rear-right cylinder IS firing, but its way off (or not burning fully). And i can idle the engine only at almost full choke position. Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted July 4, 2013 Member Contributer Share Posted July 4, 2013 Another one bites the dust ..... Sorry for the bad news !!!!! Link to comment Share on other sites More sharing options...
Member Contributer YoshiHNS Posted July 4, 2013 Member Contributer Share Posted July 4, 2013 Pop the valve covers and take pictures. Check to see if the timing is still on or not. Link to comment Share on other sites More sharing options...
Guest Posted July 4, 2013 Share Posted July 4, 2013 A couple of things spring to mind: How long have you been running with no mufflers? If only one cylinder is misbehaving it wouldn't be a cam chain or tensioner issue. But if you've been going with no muffler the engine will have been extremely lean. This is bad for reasons I shouldn't have to elaborate upon. LOL. Compression is king so the first thing to do is have a look at that. It's a pain on the V4 but it's the only place to start. If it's good, everything will fall into line--just a question of nailing it down. If not, you've got some decisions to make. OSC http://www.oldschoolcarbs.com Link to comment Share on other sites More sharing options...
Alaskan Posted July 4, 2013 Share Posted July 4, 2013 Burned exhaust valve? Link to comment Share on other sites More sharing options...
VFR4Lee Posted July 5, 2013 Share Posted July 5, 2013 Compression test is a good place to check if all plugs have a good spark. Also eyeball the plugs condition while they're out. Link to comment Share on other sites More sharing options...
Guest Posted July 5, 2013 Share Posted July 5, 2013 Compression test is a good place to check if all plugs have a good spark. Also eyeball the plugs condition while they're out. I will investigate compression and post some pics of the plugs soon. Link to comment Share on other sites More sharing options...
Guest Posted July 5, 2013 Share Posted July 5, 2013 just posted a youtube video: http://www.youtube.com/watch?v=WK_iMaA5IYo Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted July 5, 2013 Member Contributer Share Posted July 5, 2013 Cams lobes are gone . The cam is bad. She done ... Link to comment Share on other sites More sharing options...
Guest Posted July 5, 2013 Share Posted July 5, 2013 Cams lobes are gone . The cam is bad. She done ... I have two spare engines, I may be in luck! :D Im ever still hopefull. Link to comment Share on other sites More sharing options...
Member Contributer InvisibleCities Posted July 9, 2013 Member Contributer Share Posted July 9, 2013 Good advice as noted above is to remove the valve covers and inspect the valve train. VF500Fs are great bikes but often suffer from years of neglect. Lots of info out there on the great camshaft crisis & the proper adjustment of the valve lash so I'll leave this for another day. With this in mind, maintenance at the Factory recommended service intervals, along proper engine warm-up (i.e. get the engine hot before riding) & keeping the revs in check is the key to the longevity of these engines. Purchasing a Factory Service Manual is also a must have for the library shelf. Hope this works out. Good luck and keep us posted! Link to comment Share on other sites More sharing options...
Alaskan Posted July 9, 2013 Share Posted July 9, 2013 Good advice as noted above is to remove the valve covers and inspect the valve train. VF500Fs are great bikes but often suffer from years of neglect. Lots of info out there on the great camshaft crisis & the proper adjustment of the valve lash so I'll leave this for another day. With this in mind, maintenance at the Factory recommended service intervals, along proper engine warm-up (i.e. get the engine hot before riding) & keeping the revs in check is the key to the longevity of these engines. Purchasing a Factory Service Manual is also a must have for the library shelf. Hope this works out. Good luck and keep us posted! Good advice! In addition, these engines don't do well at low RPM. I never cruise below 4500 RPM. Nothing good happens below that . . . Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted July 10, 2013 Member Contributer Share Posted July 10, 2013 Cams lobes are gone . The cam is bad. She done ... I have two spare engines, I may be in luck! :D Im ever still hopefull. Excellently .... Link to comment Share on other sites More sharing options...
Member Contributer YoshiHNS Posted July 10, 2013 Member Contributer Share Posted July 10, 2013 You can never have enough spare VF500 engines. I'm hoping what's left of mine is enough to get the VF500C and the VTR250 working again. Link to comment Share on other sites More sharing options...
Alaskan Posted July 10, 2013 Share Posted July 10, 2013 We just sold our VF500F. Fun bike. Link to comment Share on other sites More sharing options...
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