A few cranks after a charge then clunk.

[eric67]

I have a 1997 challenger with a single 787. I just got the motor rebuilt. I'm trying to start it for the first time. I load tested the battery, it's about 500 cca. Today i had it 2amp charging for 8 hours. I hooked it up and cranked it 5-10 seconds to start it. I was able to do this 2-3 times, then when i try to start it i just get a clunk. Like the starter can't overcome the compression of the engine. The starter is a SBT high torque, not sure how old it is, i would guess 1-2 years. I keep charging the battery to get a few cranks then that's it. Seems like if it would crank longer i might be able to get this boat started.
all help is appreciated. :banghead:

 

[captain scale]

Will it crank with one or both of the plugs removed? Try it.

 

[eric67]

plugs out.

With both plugs removed it will crank continuously. haven't tried with just one plug the engine. The guy who i got the rebuilt engine from said he would do the timing for me. I question if the timing is right. I got a few pops through the carb tonight when i was cranking.

 

[captain scale]

Could be a weak battery, rotary timing could be off. Start with the battery though. Could be plug boots or ignition wire ends need cleaning. Clip back a small amount of the plug wire and reinstall with dielctric grease in boot. Do you get a strong spark?