spark,comp,fuel, but wont run???

[robbie1769]

Im new here but Im an experienced motorcycle tech. I have a 1977 chrysler 135 , it has good compression on all 4 aswell as spark, the carbs are spotless. It will occasionally run for a few seconds and then stop , 1 time it ran for about 1 and a half minutes , some times it will back fire but not start. I have checked the timing and it appears to be correct If im checking it right. Im checking it at wot with the pluggs out , I have also checked for tdc with a dial indicator. any thing I change seems to have no effect. It has spark , comp and fuel and at the right time to boot, why wont it run??? Im hoping that my lack of marine experience is causing me to over look some thing .

 

[jerryjerry05]

Re: spark,comp,fuel, but wont run???

What is the comp on all the cylinders? Does the fuel line have a quick disconect?Sometime they suck air.I removed everything in the line except the squeezie. How old is the ball? How old is the fuel pump? Have you checked for water in the fuel?
It could be any of the above but start with the ball then the line then the pump.Jerry

 

[JB]

Re: spark,comp,fuel, but wont run???

Have you done "Outboard won't start" in the Engine FAQs Forum?

My guess is that you are not getting adequate fuel.

 

[robbie1769]

Re: spark,comp,fuel, but wont run???

fuel is the only thing that makes sense but I have replaced the line and am using a separate tank with fresh fuel from my other boat, the bowls have fuel in them every time I have taken them back apart and jets and passages are clean. I will try to reset the float height and check the needles tomorrow morning but theres fuel geting there for sure . there are no quick connects just clamped on. I feel certain Im missing something in the fuel dept. but what? the comp is 150 aprox across the board. I just read the "Outboard won't start" and all is good but I will thouroughly investigate those carbs again tomorrow.

 

[robbie1769]

Re: spark,comp,fuel, but wont run???

ok now , thanks for your help, however I have made a huge mistake and asumed that the new plugs that were in the motor were correct. my wife suggested that maybe they were not the "correct size" . So after a day and a half , I decide to check and guess what , wrong ones , I have now installed the correct plugs and it runs perfectly. lesson to all - even new parts can be bad or in this case wrong. Now I have to tell her she fixed it.

 

[steelespike]

Re: spark,comp,fuel, but wont run???

Time to take your assistant out for a nice dinner.And maybe a special treat.