i have a 2003 suzuki z400 that has a hard time starting work preformed was new timeing chain valves tenstioners etc. ran fired up and ran great when i got it back then one day i went out to start and it just cranked over and over no it takes like tens mins of just straight cranking to get it started but be fore it would start if you would hit the gas every now and then it would pop like wanted to start i put a comp. test on it and it read 60 thought it might need new piston and rings but i was also told that with valves beeing put in they may need adjusting and the 60 might be valve blow by and they shoulda been adjusted after like 5 10 hrs after fix????? but once it fires up it don't miss a beat runs good no knocks clunks bangs etc. if it helps when cranking over forever ot smells real gassy do do i need piston and rings or do the valve just need to be adjusted in thanks

 

These are a little touchy on valve clearance. Check that first. Compression should be 142# with the throttle held open while doing test.

 

ok so i should get the valves adjusted first then and then if not it needs piston and rings its just kinda werid that it fired up and ran great untill one day and now it just takes forever to fire and it only pops and wants to start when you hit the gas untill it actually starts then fine but i will have valves adjusted and see what happens then thanks

 

hard to check commpresion with the auto decompression on the exhaust cam. pull the valve cover and check valve clearence. did you hapen to get crap in the carb? if it starts and runs good really cant see the valves being the problem. I would see if some crap got in the pilot jet. are you starting with the choke on? does it start faster if you hold the throttle open? it takes vacuum to open the carb so stay on the throttle. pumping the throttle doesent help. holding it open does. when you say it pops when you stab it seems to say it will start faster if you hold the throttle open. clean the carb.

 

yeah i have tryed to start with choke on and off it still takes bout ten mins of just cranking to to start it but when it pops it only does it when you hit throttle it seems to want to start if you just hold it open but i can't get it worked on till tomarrow but also if was carb y would it start fine everytime then one day just take ten mins to start i will have carb checked also then im just hopeing it doesnt need a piston and rings cause thats like 500 job 200 for piston and rings alone then like 50 for gaskets rest just haveing put in so i am hopeing it is carb or just valves need adjusting thanks.

 

i had the same problem id bring it to the dealer they would put a new piston in and then about 30 hours later it would do the same crap. finally i took it all apart and was looking at the exhaust valves and they werent seating right so i bought new valves and smoothed out the seating and its been fine ever since

 

i figure its not the piston just cause it seems to have good comp. when turing over so now that i got the money for it i am taking it in to have valves and carb worked on just cause it seems wo be running rich cause it backfire and snorts like a bastard thanks everyone for the help

 

Mine was starting hard like that. It was bad fuel, although the fuel in mine was 3 years old. I drained it, put new gas in, and rode it around for a while. I had to use starting fluid to get it to start the first time, but now it starts great every time.