BillingTZR Posted May 17, 2009 Share Posted May 17, 2009 Just finished getting the engine in my 1991 TZR125, had some fun with getting the fuel tap to stop letting fuel through on the 'OFF' position. I managed to get her to fire up for the first time since I bought her. The main problem is that it won't run for very long (10 secs at best) it then makes a loud crack like a christmas cracker and cuts out the next problem is that after setting the float height it still lets fuel out of the 2 pinkish overflow pipes and the float bowl drain pipe, can anyone tell me why its doing it or how to fix it please? desperate to get it sorted so i can ride it! Link to comment Share on other sites More sharing options...
JimR Posted May 17, 2009 Share Posted May 17, 2009 Just finished getting the engine in my 1991 TZR125, had some fun with getting the fuel tap to stop letting fuel through on the 'OFF' position. I managed to get her to fire up for the first time since I bought her. The main problem is that it won't run for very long (10 secs at best) it then makes a loud crack like a christmas cracker and cuts out the next problem is that after setting the float height it still lets fuel out of the 2 pinkish overflow pipes and the float bowl drain pipe, can anyone tell me why its doing it or how to fix it please? desperate to get it sorted so i can ride it! Hi I would guess the fuel running out of the over flows you either have the wrong float height or the needle shuting off the fuel supply is suspect. your back fire (cracker thing) could be down to the CDI playing up, as the unit warms up the signal sent to the coil/plug is then confused and the spark will arrive at the wrong time. This problem could be down to either the CDI unit or the pulse coil (and of course bad earths) so perhaps run thro the whole ignition system Regards Jim Link to comment Share on other sites More sharing options...
BillingTZR Posted May 17, 2009 Author Share Posted May 17, 2009 Hi I would guess the fuel running out of the over flows you either have the wrong float height or the needle shuting off the fuel supply is suspect. your back fire (cracker thing) could be down to the CDI playing up, as the unit warms up the signal sent to the coil/plug is then confused and the spark will arrive at the wrong time. This problem could be down to either the CDI unit or the pulse coil (and of course bad earths) so perhaps run thro the whole ignition system Regards Jim Hi Jim, I would have expected that if the CDI was at fault it would stop functioning altogether, but will take it into account. I set the float height as per the manual, after getting no joy I set it slightly higher, it now overflows only after being started, I have bought a new plug for it so will check the old one when I change it. All of the jets are clear, I had the carb apart earlier today, gave it a proper clean, and still it doesnt like it =/ Link to comment Share on other sites More sharing options...
JimR Posted May 17, 2009 Share Posted May 17, 2009 Hi Jim, I would have expected that if the CDI was at fault it would stop functioning altogether, but will take it into account. I set the float height as per the manual, after getting no joy I set it slightly higher, it now overflows only after being started, I have bought a new plug for it so will check the old one when I change it. All of the jets are clear, I had the carb apart earlier today, gave it a proper clean, and still it doesnt like it =/ Hi, nope the cdi unit did not just stop working it produced loads of odd miss fires, bikes stoping when load applied to the charging system etc. so setting the float height wrong you end up with a leak, and the point that the bike only leaks when hot/warm would follow that through (wrong float height). I guess its time to look at what you have done. Regards Jim Link to comment Share on other sites More sharing options...
BillingTZR Posted May 17, 2009 Author Share Posted May 17, 2009 Hi, nope the cdi unit did not just stop working it produced loads of odd miss fires, bikes stoping when load applied to the charging system etc. so setting the float height wrong you end up with a leak, and the point that the bike only leaks when hot/warm would follow that through (wrong float height). I guess its time to look at what you have done. Regards Jim it never runs for long, so doesnt get hot really, it had the leak both before and after setting the float height, for the few seconds it runs its very smooth, and revs up a little, but as soon as load is applied it backdires and cuts out, then it starts leaking out of all the overflow pipes, im considering taking it to a garage to have them fix it for me. Link to comment Share on other sites More sharing options...
JimR Posted May 17, 2009 Share Posted May 17, 2009 it never runs for long, so doesnt get hot really, it had the leak both before and after setting the float height, for the few seconds it runs its very smooth, and revs up a little, but as soon as load is applied it backdires and cuts out, then it starts leaking out of all the overflow pipes, im considering taking it to a garage to have them fix it for me. Hi, I would guess backdires = back fires ...? If that is the case I would guess the pulse coil has failed but there is the point that the CDI and/or stator could have failed to ... the fuel leak will be down to worn out carb bits ... having a shop to fix it may cost mega cash Regards Jim Link to comment Share on other sites More sharing options...
BillingTZR Posted May 17, 2009 Author Share Posted May 17, 2009 Hi, I would guess backdires = back fires ...? If that is the case I would guess the pulse coil has failed but there is the point that the CDI and/or stator could have failed to ... the fuel leak will be down to worn out carb bits ... having a shop to fix it may cost mega cash Regards Jim Yeah, i meant back fires, just a bit sleepy as i woke up at 5am to get a whole day in to work on it it tried again by filling the float bowl up, disconnecting the fuel tank to avoid the leak. when it back fires it spits unburned petrol out of the exhaust, but will check the pulse coil, CDI and stator. I also quickly put a different carb on and it still leaked out of the same place. I can get it done reasonably cheaply, so if i can't fix it ill send it there, what with college exams coming up as well as a whole welding course to finish before june 5th i don't have the time to mess about with it tbh Link to comment Share on other sites More sharing options...
JimR Posted May 17, 2009 Share Posted May 17, 2009 Yeah, i meant back fires, just a bit sleepy as i woke up at 5am to get a whole day in to work on it it tried again by filling the float bowl up, disconnecting the fuel tank to avoid the leak. when it back fires it spits unburned petrol out of the exhaust, but will check the pulse coil, CDI and stator. I also quickly put a different carb on and it still leaked out of the same place. I can get it done reasonably cheaply, so if i can't fix it ill send it there, what with college exams coming up as well as a whole welding course to finish before june 5th i don't have the time to mess about with it tbh Hi, done this one loadsa times now you have metioned the fuel being expelled... do your exams etc & when you are ready I'll give you the load down ! Regards Jim Link to comment Share on other sites More sharing options...
BillingTZR Posted May 17, 2009 Author Share Posted May 17, 2009 Hi, done this one loadsa times now you have metioned the fuel being expelled... do your exams etc & when you are ready I'll give you the load down ! Regards Jim cheers i have sundays free, and would love to hear any advice you may have, then if i have an evening free i can try out any suggestions, Link to comment Share on other sites More sharing options...
robertjames1984 Posted May 17, 2009 Share Posted May 17, 2009 Check you haven't got a crack in the float bowl round the base of the overflow i had this problem on my nsr125, fuel was leaking out of the over flow, no matter where i adjusted the float height. Link to comment Share on other sites More sharing options...
BillingTZR Posted May 17, 2009 Author Share Posted May 17, 2009 Check you haven't got a crack in the float bowl round the base of the overflow i had this problem on my nsr125, fuel was leaking out of the over flow, no matter where i adjusted the float height. definately not a crak in the bowl as the fuel actually comes out of the pipe, i did check by blocking the float pipe and then the leak stopped but still came from the two upper ones Link to comment Share on other sites More sharing options...
JimR Posted May 17, 2009 Share Posted May 17, 2009 Check you haven't got a crack in the float bowl round the base of the overflow i had this problem on my nsr125, fuel was leaking out of the over flow, no matter where i adjusted the float height. That's a Honda thing built in Italy the TZR is one of the last jap produced bikes. If the NSR is in the same genre your float bowl problem this may have been down to sub standard manufacturing ! Regards Jim Link to comment Share on other sites More sharing options...
BillingTZR Posted May 17, 2009 Author Share Posted May 17, 2009 That's a Honda thing built in Italy the TZR is one of the last jap produced bikes. If the NSR is in the same genre your float bowl problem this may have been down to sub standard manufacturing ! Regards Jim its definately not the float bowl what do you think the problem is Jim? is it something rediculously complicated or dead simple? Link to comment Share on other sites More sharing options...
BillingTZR Posted May 18, 2009 Author Share Posted May 18, 2009 Still no luck now it won't start at all, I'm going to change the plug, but after that if it doesnt start then I'm lost for ideas Link to comment Share on other sites More sharing options...
JimR Posted May 19, 2009 Share Posted May 19, 2009 Still no luck now it won't start at all, I'm going to change the plug, but after that if it doesnt start then I'm lost for ideas Hi have you replaced the plug yet ( I hope you checked for a spark b4 you put it in) and retried to start the bike ? Still no joy ? how did the new plug come out after attempting to start the bike. Regards Jim Link to comment Share on other sites More sharing options...
BillingTZR Posted May 19, 2009 Author Share Posted May 19, 2009 Hi have you replaced the plug yet ( I hope you checked for a spark b4 you put it in) and retried to start the bike ? Still no joy ? how did the new plug come out after attempting to start the bike. Regards Jim I changed the plug and it run without cutting out! I'm absolutely ecstatic! Link to comment Share on other sites More sharing options...
BillingTZR Posted May 19, 2009 Author Share Posted May 19, 2009 Need help! going along a private road, it started billowing white smoke from the exhaust, the choke was on at this time. It then cut out, is it probable I've fouled the plug by using the choke for too long? If i give it a good clean is it likely to fix it? it was running well for around a mile, I assume this was while the engine was still cool and it fouled once it got warm. On a good note I had 80mph in 5th with about 1000rpm left before redline Link to comment Share on other sites More sharing options...
JimR Posted May 21, 2009 Share Posted May 21, 2009 Need help! going along a private road, it started billowing white smoke from the exhaust, the choke was on at this time. It then cut out, is it probable I've fouled the plug by using the choke for too long? If i give it a good clean is it likely to fix it? it was running well for around a mile, I assume this was while the engine was still cool and it fouled once it got warm. On a good note I had 80mph in 5th with about 1000rpm left before redline Hi yep you choked it out ... you should drop the choke off in a few secondsa after starting or the bike will fourstroke badley & if left on longer it will just end up well too rich & die ... This is more noticable if the bike is being ridden at some thing less than full bore !!!! Regards Jim Link to comment Share on other sites More sharing options...
BillingTZR Posted May 21, 2009 Author Share Posted May 21, 2009 Hi yep you choked it out ... you should drop the choke off in a few secondsa after starting or the bike will fourstroke badley & if left on longer it will just end up well too rich & die ... This is more noticable if the bike is being ridden at some thing less than full bore !!!! Regards Jim Ok, I thought it was that, I guessed in the partial light it looked white, but may have been pale blue. The current plug keeps fouling, so I have a new new one, and will very very slightly lean the mixture off, its at factory spec (1 3/4 turns out) and is very rich, after trying to start the plug is soaking wet with fuel Link to comment Share on other sites More sharing options...
JimR Posted May 21, 2009 Share Posted May 21, 2009 Ok, I thought it was that, I guessed in the partial light it looked white, but may have been pale blue. The current plug keeps fouling, so I have a new new one, and will very very slightly lean the mixture off, its at factory spec (1 3/4 turns out) and is very rich, after trying to start the plug is soaking wet with fuel Hi, Crash course with TZR's To start from flooded switch the fuel off, no choke and the throttle wide open after some pushing or kicking the bike will start (if well flooded pushin starting would be better). What grade of plug are you using ? Is the bike std ? & don't forget the mix screw only adjusts the bike while it is running (it is possible to start the bike with the screw in whatever position but it may not idle too well and run well else where OK). Other problems that may cause a soaked plug is a lack of compression or the carb in need of cleaning and lastly the ignition circut up the duff. I guess it would be good to 'redo from start' (to coin an early computer phrase) and just check the lot out ! Regards Jim Link to comment Share on other sites More sharing options...
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