ReBorne Posted June 26, 2010 Share Posted June 26, 2010 Ok, I'm really at the end of my tether with my damn FZ400. Starts ok. Runs ok, ticks over ok. Rides ok. After about 3/4 mile - cuts out, won't re-start. Leave it a couple of hours - restarts ok, runs once again and then does it again. Checked the petrol, not a problem, getting through fine. Checked the carbs as much as I can, seem ok. Someone suggested the coils - just ran it around a little while until it cut out, checked for a spark - yup, no problem there, spark to all 4 plugs. Had it idling in the garage for a while before it cut out today - not long before it happened she started sounding as though she was missing a cylinder, but just every now and then. Anyone got any ideas? Seriously, this is doing my head in bigtime, I'll consider checking anything else now.... Cheers! Link to comment Share on other sites More sharing options...
Moderator Beezkneez Posted June 26, 2010 Moderator Share Posted June 26, 2010 Ok, I'm really at the end of my tether with my damn FZ400. Starts ok. Runs ok, ticks over ok. Rides ok. After about 3/4 mile - cuts out, won't re-start. Leave it a couple of hours - restarts ok, runs once again and then does it again. Checked the petrol, not a problem, getting through fine. Checked the carbs as much as I can, seem ok. Someone suggested the coils - just ran it around a little while until it cut out, checked for a spark - yup, no problem there, spark to all 4 plugs. Had it idling in the garage for a while before it cut out today - not long before it happened she started sounding as though she was missing a cylinder, but just every now and then. Anyone got any ideas? Seriously, this is doing my head in bigtime, I'll consider checking anything else now.... Cheers! breather pipe blocked? Link to comment Share on other sites More sharing options...
Moderator mervin Posted June 27, 2010 Moderator Share Posted June 27, 2010 is the tank venting properly, when it stops undo the fuel cap and see if it sucks in air, is there a fuel filter that is patially? blocked or it could be the CDi breaking down merv Link to comment Share on other sites More sharing options...
ReBorne Posted July 12, 2010 Author Share Posted July 12, 2010 Thanks guys. Have tried both of these previously, no go. Since that post I've had the carbs off and stripped right down, then cleaned them out using redex in my airbrush to make sure it gets right in to every part. FLushed the tank and all pipes too. Admittedly, carbs were dirty as hell, especially inside the pots. After that she went for almost exactly 3km then died. Started after 5 mins, almost passed her MOT, then going home exactly the same again. 3km then dead. I'm thinking,loogically here - that 3km must be the amount of petrol held in the pots on the carbs. GOOD NEWS though. After all the standing and the absolutly stupid amount of time it's taken for me to get the thing back on the road, she failed her MOT on just 3 things - fork seal leaking, chain too tight and rear swing arm not allowing her to rebound properly. Work is all done and she is heading in for retest. However, driving her back there - same thing has happened again!!! Cut out! The last thing I can think of is the tap. I'm thinking it's not letting fuel flow when it should be. Gonna try this over the next night or so by disabling the vacuum function like I've found on some sites. Will let you know what happens. If there's a report of a bike in the river before then, you know the score :-s Link to comment Share on other sites More sharing options...
FZR AL Posted July 13, 2010 Share Posted July 13, 2010 Could you not hook up a mini fuel tank, with an old emergency fuel carriers, do a direct link to the carbs, and give it a try then you would know if its fuel delivery or not , could be that there crap in the fuel tap or the tank it self. Link to comment Share on other sites More sharing options...
Paulwhite Posted July 13, 2010 Share Posted July 13, 2010 i know its a long shot but have you checked your battery connections? mine did something similar ! would start and run fine but a mile and a half down the road and it would cut out found out that the earth from the battery wasnt on properly. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted July 13, 2010 Moderator Share Posted July 13, 2010 Eyup Mike. You could do no harm by checking you still have a spark after it cuts out at 3km, this 3 km could be as you suspect, ie fuel starvation. But it could also be that 3km puts enough heat into the engine to break an electrical component...such as a pulse coil or ignition coil. Just whip a plug out to see. Link to comment Share on other sites More sharing options...
ReBorne Posted July 13, 2010 Author Share Posted July 13, 2010 Thanks again for the response guys. Coils? Checked. Still gets a spark ok on all 4. Battery? Checked. Along with wiring for loose connections and possible chafing. Fuel tank seems to be letting fuel through in general whenever I check it - including when I had the tank off and to one side (but still attached at the fuel lines) when I was setting her idle speed. But it's hard to check when both fuel pipes are on, hence my thinking it may be the vacuum tap. Whenever I disconnect the fuel line a splash of fuel comes out. oh, and I've flushed the tank out completely already. There was crap in there from her standing which us what she was pulling through to make the carbs so messy before I cleaned them. Tonight I took the tap off the tank and opened it up - didn't look too brilliant inside to be frank - rubbers a little worse for wear. I'm bypassing the vacuum part of it simply by taking the spring out from behind the valve thingy and moving it in front - so instead of it holding the valve closed it holds it open to eliminate that as an option. (After reading some of the work other people have done to get the same effect I'm quite surprised no-one mentioned doing it this way. The spring fits in the other side nicely.) I realise I'll have to remember to turn the tap off when she's standing, but small price to pay. Now the fuel has a straight run through when the tap is open. Will be re-fitting tomorrow or Thursday morning. As the bike is currently sitting at a friends about 2/3 of the way to the bike shop, it should at least get it's MOT. Fingers Crossed this works :-S Link to comment Share on other sites More sharing options...
FLYIN BRIAN Posted July 14, 2010 Share Posted July 14, 2010 I had an old Chrysler that exibited similar symptoms. It took me 2 Years to sort it out. I had used Seal All to plug a screw hole (along with a screw). It's supposed to be good in fuel systems. Long and short of it is that it had begun to dissolve into the fuel and would coat the pick-up screen, stalling the engine. Within a few minutes it would float away and Id' have fuel again. Sound familiar? Link to comment Share on other sites More sharing options...
Moderator Airhead Posted July 14, 2010 Moderator Share Posted July 14, 2010 so is there an 'off' position on the tap? Many vacuum taps dont have this, the fact there is no vacuum means they are off. Check yours is turning off now or fix it ASAP Link to comment Share on other sites More sharing options...
ReBorne Posted July 18, 2010 Author Share Posted July 18, 2010 Hi OldGit - I don't think the tap has on off. Truth be told, I don't know 100% what the tap positions are. Yamaha in their infinite wisdom put this information on the side panel next to the tap. Which has had a respray :-S. I'm pretty sure I know reserve which is what it is on at the moment, and ON is the opposite (or so I believe). Don't know what the centre one is yet :-S Brian, thanks for that one - but I've ruled out anything getting into the fuel system now in any way shape or form. Stripping down the carbs and using red-ex in my airbrush to get into EVERY tiny cranny, and the compressor blasting air through all the pipes etc. Good news overall though. She passed her MOT yesterday and I get tax today, so she's road legal. Bringing her home, of course, she cut out - less than a km from there. Pushed her home and put the battery on charge - flattened it trying to start her. I took her around the streets a little last night, let her run, took her around again, let her run, and again, let her run.....and run... and run. She overheated kicking water out of the reserve water tank at the side. Ok, so most people wouldn't be happy at their bike overheating, but I was well chuffed. It means she ran LONG ENOUGH to overheat!!! lol. So, it's now showing itself to be an intermittent problem. The 3km twice was probably co-incidence. That, to me, rules out lots of things - but means that something quite random is happening. One thing I've noticed in the past is the amount of excessive wiring underneath the tank. I'm gonna bag that all off and tie it up out of the way. (Never done it before now as I've been going under there so much). I've ruled out fuel, mechanical and ignition so there isn't much left. (And thinking on, I DID move them out of the way a little to get at the breather pipe underneath the tank before she did the long run). Thanks to everyone so far for the suggestions. God, I hope this sorts out soon. I just wanna get out on her now - well, for a couple of months till I strip her down and make her look good ;-) Link to comment Share on other sites More sharing options...
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