Posted July 30, 2024Jul 30 Morning chaps, Been happening for a while now but more so when it gets hotter outside. Starts good when cold, drives and pulls like a train. My drive home takes 30 mins through some heavy traffic and filtering. When stopped at a traffic light or when I get home to open the gate the bike starts spluttering, misfiring and dies. At a a traffic light I have to keep the revs at or above 2000 rpm. Have looked at various forums but nothing conclusive ranging from carb settings, vacuum leaks etc. My bike shop guy has turned up the idle a bit and he thinks it may be the coils getting hot after a bit and might need to be replaced. Any ideas ?
July 30, 2024Jul 30 53 minutes ago, DutchFJ1200 said: he thinks it may be the coils getting hot after a bit and might need to be replaced. He may well be right Dutch. I had something similar years ago on my 400/4, that has twin coils under the tank directly above the engine. One of them was playing up especially in hot weather. Heat from the engine and warm air from the environment was too much for it and it would often play up in the summer months. A replacement solved the problem. mind you it did take a long time to trace the cause!! Not expensive.. https://www.squaremotorcycleparts.co.uk/products/ignition-coil-yamaha-fj1200-fj-1200-1988-1994 worth doing for that price, and yours will be 32 years old already if original!!
July 31, 2024Jul 31 Author You Sir get the Platinum medal today 🙂 lol Shoot.... thanks for the link. I normally get my gear from Wemoto ...... they are double that price https://www.wemoto.com/bike/yamaha/fj/1200/1992/28776/ignition-coil
December 24, 2024Dec 24 Author Merry Xmas all, Sorry for the late update. I was locked out of my account and getting back in is like trying to get into Fort Knox. The saga continues. Anyhoo, the el cheapo coils did not fit my bike so fortunately I could send those back. Enter 2 OEM coils @ 150 quid a pop + installation. Did it change anything ? ..... Nope. Commuting home and sitting in traffic, filtering at slow speed and stopping for a red light from time to time and after a while it starts hunting, then spluttering so I have to keep the revs up so it doesn't die. What I did discover with an infra red thermometer is that - if cylinders are numbered from left to right - when it was running but misfiring : 1 was at 220 degrees, 2 was at 150 degrees, 3&4 were at 290/300 at idle. So cylinder 2 is not behaving. WHY ?? Next move was to put new plugs in 1 & 2 because they might have been affected by the old misfiring/overheating coils. The coils fire 1 & 3 and 2 & 4 so I have been told. The coils can be ruled out because number 4 is okay so the thinking is mechanical. Valve clearances, carburation or whatever else can go on down there. I did tell the mechanic chappy that experimenting at my expense is no longer an option, but he agreed that if he could have to bike for a bit he would try to get to the bottom of this issue foc. He is baffled by the whole thing as well. I'm still riding the bike to work but I now have misfiring anxiety on the way home lol 😅 If the traffic lights align and traffic is light and I can make it home in one hit without stopping I'm fine. **if we get to the bottom of this it may not have been my coils at all ....... now that will be an interesting conversation with the guy** Edited December 24, 2024Dec 24 by DutchFJ1200
January 2Jan 2 Author On 12/24/2024 at 3:16 PM, Snakebite68 said: No codes? I don't think they had invented codes yet in 1992 😅
January 3Jan 3 Happy new year to you Dutch, sorry to hear that those coils I sourced didn't fit your bike and you ended up paying out for an OEM set, which still didn't cure your problem. I assume then that a 92 bike will be some sort of electronic ignition, bearing in mind my 78 DT does, albiet an early form. What's the carburation on it? is it carbs or fuel injectors? If this was a car ,which back then were mostly fuel injected, and the coil pack has been eliminated then the culprit would likely be the ECU. If it has an ECU then the fault codes are a series of flashes on the dashboard of cars from that era. You read them by putting in the key and counting the flash codes, which you then look up to find the corresponding fault code. I'm not saying for one minute that this will apply to your bike, just that codes were around in the early 90's on many vehicles, and were the predecessors to the ODB2 that you find on modern vehicles. Do any bulbs happen to flash/or LCD segments blink when you put the key in by chance?
January 3Jan 3 Found you a service guide for your bike, looks like the ECU does give you fault code lights!! it states:- In this case, the memorized fault codes can be identified by putting the ECU into the diagnosis mode and using a circuit tester or the warning light page 13 onwards. I think reading through it, the ECU does the ABS and Ignition, either way worth a read or showing to your mechanic. We're not allowed to link to content elsewhere, so once you've had a look I'll re-edit my post and remove the link. Link removed.
January 3Jan 3 ...and just thinking, whilst we don't want to lose you, have you thought of joining the FJClub and asking them for advice? someone else may have had a similar fault. https://www.fjownersclub.co.uk/
January 4Jan 4 Moderator Or, there's the expensive / buggeration option: When was the last time your valve gaps were done?
February 8Feb 8 Author Thanks for the pointers chaps. First port of call now is carburetor. Bike shop chappie pointed me to https://www.bentleymotorcycles.com/contact Martin only does carbs and don't spanner on bikes so its carbs out. I now also know why bike shop chappie does not want to take the carb out .... lol. its not rocket science by you nearly have to take half the bike apart, i.e split the rear frame to create enough room between the airbox and the carbs & rubber boots. Then he has a bike in bits clogging up his small shop. I'm not giving up on this thing yet..... what else am I going to do with it.😐 Snakey, yep valve clearances is next and if that don't work, Neo .... FJclub after that.
February 8Feb 8 Author Other question : I have now experienced that the carb/airbox setup is a bit pants on the FJ1200 and many people across many forums think the same. Many have ditched the airbox in favour of K&N style separate cones as air intakes. This any good : https://www.ebay.co.uk/itm/350629336722?fits=UKM_Make%3AYamaha&_skw=yamaha+fj1200+air+filter&epid=8007973252&itmmeta=01JKJYEDJ288QVKKZA45PZ7R1W&hash=item51a3231692:g:RfcAAOSwrXhfv4Ys&itmprp=enc%3AAQAJAAAA8HoV3kP08IDx%2BKZ9MfhVJKlk%2FoqzRo2TwJN9piCP1lzFwm3QeuY81LCW0XrLai%2F4dXyeJ3RjtPcVyIvL3XHu7%2FlrMTAcZxZhwmpi8b22%2FGzQwIEaM9dgA2jWq%2F6TJPdhFiJij%2BXI7%2FZUjFu5lfKKzePw4WogcEsGmiOUdvCfnEmeJkFYYfGmzXTXkiN9WK3PUfPEDUJ1MfCkyODuJs5L1FbxVoGJ6jEcCORlMewWKpPEa5Ja6QrHJUyF3Bb3eejHkFSn4uYWG37aFsXPiEOD8VaehIreiN%2FhyDQwC4ArRQzjU9bE3dQ%2F7%2BJydcgNfkBgyA%3D%3D|tkp%3ABFBMmNm53pxl or https://www.ebay.co.uk/itm/116435735953?fits=UKM_Make%3AYamaha&_skw=yamaha+fj1200+air+filter&itmmeta=01JKJYEDJ2D85VV5AT7G93Z2MD&hash=item1b1c1c5591:g:xeMAAOSwRb9nd5D3&itmprp=enc%3AAQAJAAAA8HoV3kP08IDx%2BKZ9MfhVJKlsJbyw8rHXQb4tsX2RTIJf%2BdFdi6yupUfsM2DpN2JgxuWGHbPigk2QM5hfoqtLSYPMAkxmiUoFI5O5nKRQdh8zehuzcrFkcKhpMJj02C9GXx%2FhlhzyV5tQI1AfC%2Bmf0Z7XgYNFnixGSMZDHKgnLr%2FjDSF%2FLKdM2H9ajyUa6OsXYFn2sSHYAD%2BNmkim3rAlHNMvGhoVAVdGr%2FU6D1k3cW1hRw0iad%2FuvwHVi3pXuiNz78wTdRCEkrlMnnRzT%2FKEI99Lbgo1cX%2FZP3Qp9Zc5jmsKMYaxxNdKByhAqFORcLxQ4A%3D%3D|tkp%3ABFBMmtm53pxl Any views on that? Edited February 8Feb 8 by DutchFJ1200
February 8Feb 8 Moderator I have no preference for either of those, however... Just bare in mind that if you get 'oil' air filters, there's a lot of work involved keeping them good. Yes, they are great, however. If you don't put enough oil on them or don't clean them and replace the oil on a regular basis, they don't work properly... If you put TOO MUCH oil on them, then they suck that into the engine and / or clog up..! With either option, I suspect you'll have to do a lot more work / more frequent checking than the standard paper filters.
February 8Feb 8 Author Snakey, Please explain 'oil' air filters. I can do a bit of spannering but I'm not a mechanic. afaik air filters only keep dust out of the carbs no? Edited February 8Feb 8 by DutchFJ1200
February 8Feb 8 yeah its odd Dutch but...'oil' air filters are, instead of paper elements to trap the dirt particles, oil is used over a wire mesh like steel wool to trap the dirt particles. The proper name, is Wet air filters and Dry air filters. Replaceable Paper elements were first introduced in the 60's/70's for cars and it wasn't uncommon to have the early model versions of the car with Wet air filters and the later production ones being Dry filters, now of course they are all dry. With paper filters you replace the paper element, and with oil filters, you wash out the wire wool part and replenish the oil. Both require maintenance to remain effective at trapping the dirt. ...and oil tends to get outside of the filter and the once clean looking chrome/steel, ends up being black and dirty and require cleaning !!....but at least they won't rust!! I notice on your two ebay links, the first one has a black sock to cover them up and hide them!! whereas the second link shows nice steel wire/mesh without oil, that will look black after they start doing their job and only look nice and shiney on the first day!!🤣
February 8Feb 8 Author Hmmm, with the bike's subframe now disconnected its easy to put the carbs and the box back in. Would need a few new inlet boots though. F*ck these things are expensive https://www.cmsnl.com/products/jointair-cleaner-2_36y1446300/ Anyhoo, lets get the carbs to the doctor first and see what he says. Oh the joys of owning a 32 y/o machine.🙄
February 9Feb 9 Rubber parts are often the most expensive parts of a bike thats for sure!! I see Fowlers have them on ebay! as you say not cheap £53 each!! but they do list them, heres number 2, the others are listed also. i guess you've probably seen them. https://www.ebay.co.uk/itm/362541278424?fits=UKM_Make%3AYamaha&_skw=yamaha+fj1200+air&epid=23026296538&itmmeta=01JKNBCV502QQ7R7N5H5VQQ5QG&hash=item546924e4d8:g:NuYAAOSwaZdmAunf&itmprp=enc%3AAQAJAAAA0HoV3kP08IDx%2BKZ9MfhVJKl3Z%2BXqmaqMUuOecYnyH3yb2U7p421Z4QDd7Qsn%2BoKPW2MIik4O6ekDqbd%2BjkKJYGCJxc0ulj9M7BwWufGD7txEYpLOUB5S3msnSYktZlZ55PKkz9LzFJWA1VDFwpJWP60ns0uQViKNFuCGKwZa3QwAENwgiLwIUzjiHU4R%2FelXKQkZEJrYXo9wL5GQZ05oeVBpPUQ3OXMiHTG%2F6nAZ8Wn4upsKfbog5vVsUY8PNbHawNOGw1E6NB0gUkQZESKfBfk%3D|tkp%3ABk9SR-ays6udZQ
February 9Feb 9 Moderator 23 hours ago, DutchFJ1200 said: Snakey, Please explain 'oil' air filters. I can do a bit of spannering but I'm not a mechanic. afaik air filters only keep dust out of the carbs no? Yeah, as Neo said, wet filters (I just couldn't remember what they were called...). Like K&Ns.
Monday at 02:27 PM4 days Author update Dr. carburetor said it needed diaphragms, float valves, gaskets, miscellaneous parts & labour. Sooooo it's safe to assume they were pretty fucked. Now all done and ready to collect £270 quid.😱 This is becoming an expensive hobby.
Monday at 06:46 PM4 days Moderator 4 hours ago, DutchFJ1200 said: This is becoming an expensive hobby. If you're only just figuring that out, this must be your first bike (not counting anything back in the 70s/80s)... It's not the bike, it's not even the insurance, it's the damn ancillaries! lol Helmet, Jacket, Trousers, Gloves, Boots. Then you need a lock & chain... Then you need a lighter security option... Then you need a different lighter security option because the first one turned out to be crap... Then the Summer comes round and those nice Trousers & Jacket are way too hot, so you need a lighter set... Then you've forgotten your big Gauntlets and need a lighter pair... THEN, you start doing little bits & bobs to your bike and decide you need a paddock stand... Then you realise you need a FRONT paddock stand... Then, if you don't already have them, basic tools... Then more specific tools... Then expensive tools... Then your basic tools are too basic and you want a better set... THEN, your Helmet times out and you need another one... THEN, you get another bike, and your gear is the wrong colour and it all starts again..!!!
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