My first bike - KZ750B4

No eBay APP ID and/or Cert ID defined in Kunena configurationAlright, got the charging system sorted out. Cleaned every connector between the rear fender and the headlight and cleaned up/changed the ground wires connections and the battery is now around 14.5 at 4000 RPMS.
Thank you for that suggestion Mission. I did not realize how many connectors there were, I thought a lot of them were soldered connections that had been covered up.

BUT, the charging system was just a coincidence in my running issues, the bike is still backfiring and bogging down after 10 minutes or so of parking lot riding. I am now thinking that I have either a ignition coil issue or fuel issue. It may very well be I am having issues with both.

Ignition Coil

I examined and tested the coil today (cold bike) the primary winding was at within spec at 4.1 ohms but the secondary winding was high and out of spec at 28.3 kohms (within spec is 10.4-15.6 kohms). There are mixed plug caps on the bike now so there was some modification done previously. It looks stock and is stamped Hanshin but has a blue and black/white wire not blue and yellow/red like the manual states.Does this mean definite replacement of the coil?
Bountyhunter, I have read a post previously where you recommended that if there is any suspicion of defective coil on an old bike then just go ahead and get a replacement but that was some time ago when Z1 still stocked an oem replacement.
if so, what are your recommendations? What are your thoughts on this?



Fuel system
On these carbs there is a drain screw and a horizontal overflow nipple coming out of the carbs. It is not one piece like i have seen on other carbs. The horizontal brass overflow nipple has been dripping since I have had the bike. I found a post from 650ed which provides some potential causes of leaks.
1 - float valve not sealing - I took the bowl off the carb and cleaned the float valve needle and the piece of the float where the needle sits with a qtip and carb/choke spray cleaner. The bowl and underside of the carb looked clean. Did not fix issue.
2 - overflow tube broken - I filled the bowl up with water and there was no drip out of the bottom of the drain
3- fuel level is too high - I guess this is my issue. I attempted the clear tube method today with the clear tube on the horizontal overflow tube and just let the fuel rise because of the leak and it filled to about 5mm below the carb line. I am going to attempt this again tomorrow and loosen the drain screw to see if it causes a change. I do need to replace the drain screw because I do not think its original. Its a flat head screw and its all chewed up. I wonder if this could contribute to the leak.
It is such a pain to get the bike leveled because the center stand is not on the bike.

I am not sure the fuel issue lines up with my complaints with the bike running poorly after a few minutes of riding but I have found that the running issue sometimes does coincide with me turning the choke (enricher circuit) off. I guess I can try and dial in the fuel level and then follow the idle adjustment procedure in the manual by setting the pilot screw limiters and then adjusting the idle screw and see if that solves the running/idle issue.

There are so many things to check but with me being a newbie the order of things causes a huge headache.

WHEW, that was a long one! Hope you guys stayed with me. If any mods think I should move this I will definitely post it somewhere else just did not want to create a new thread for every little thing that I come across. It may make sense for me to move it to a technical forum.

Thank you guys. My knowledge of bikes/carb engines has increased immensely but there is still so much to learn.

Jordan

Have you checked your float levels? Sounds like the bike may be flooding out with gas after running for a bit? Which carbs are on ur bike? Are they CV? Maybe your vacumm line has an issue and isn't allowing fuel to stop flowing without vacumm?

sleepinsilvia23 wrote: ... I guess this is my issue. I attempted the clear tube method today with the clear tube on the horizontal overflow tube and just let the fuel rise because of the leak and it filled to about 5mm below the carb line. I am going to attempt this again tomorrow and loosen the drain screw to see if it causes a change. I do need to replace the drain screw because I do not think its original. Its a flat head screw and its all chewed up. I wonder if this could contribute to the leak.
It is such a pain to get the bike leveled because the center stand is not on the bike.

Hi sleepinsilvia2,
I have the same bike as yours. What I don't understand is that the over flow drain should not behave as you describe, The correct fuel level is 4.5 to 6.5 mm below the upper carb body so your 5mm sounds fine. Unfortunately if that is the correct fuel level there should be no fuel flowing out of the over flow unless there is a leak in the over flow system. I've attached a section view of the carb. I know that it shows a vertical overflow drain but it's right out of the FSM.

I believe that the only way to set the fuel level is, as you attempted, with the wet method because I think that the alcohol in our fuels attacks the foam floats and makes them heavier.
Good Luck

Bill