88 merc IL 6 115 compression

[walterV]

hello again,<br /> I have rebuilt carbs, and fuel pump. It still bogs down intermittently. I replaced the switch boxes and checked the coils for cracks. It will run great sometimes and then it bogs down trying to get it on the trailer. It will crank right up and rev up using the lever, then put it in gear and try to pull up on the trailer and it bogs down again. I took compression check on all but one cylinders, #1 was 122, #2 was 120, #3 was 105, #4 was 103, #5 was 101, could not get guage on #6. Do i need to rebuild motor to fix bogging and low cylinder problem? Help, walt

 

[phatmanmike]

Re: 88 merc IL 6 115 compression

doesnt sound good, chief. you need to do a good decarb and see if those numbers can come up a bit.<br /><br />keep posting

 

[walterV]

Re: 88 merc IL 6 115 compression

thanks for the info. What should the compression be?<br /> Is the 102 and 103 too low to properly fire the plugs?<br /> Could this be the reason it runs good one minute and bogs down the next?<br /> walter

 

[DJ]

Re: 88 merc IL 6 115 compression

Decarb process here:<br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=36;t=000016 <br /><br />100 psi is more than adequate.<br /><br />You may want to check your idle circuit richness.<br /><br />A rich mixture, at idle, can sometimes cause a "bog".

 

[walterV]

Re: 88 merc IL 6 115 compression

sorry i didn't explain more. It " bogs " or stalls intermittently when going to higher throddle position. It idles great and goes into forward and reverse gear without any stalling. when i try to put it back on the trailer, the last foot is when it starts stalling as i give it more throddle, then it stalls out. I crank it right up and clear it using the lever, then try it again with the same results.

 

[DJ]

Re: 88 merc IL 6 115 compression

Your carbs are not working together. With the incline, on the trailer, you may be flooding the crqankcase with raw fuel.<br /><br />Reset your idle speed jet adjustments, in the water.

 

[walterV]

Re: 88 merc IL 6 115 compression

I decarbed my engine, the idle is smooth and steady. I'am not sure about the carb adjustment. the rpm's is 1100 at idle out of gear, put it in gear and it idles at 900. The timing advances to 1300 rpm's then the throddle valves start to open, thats when it starts to stall. I raced it up several times going a little higher each time until it passed the hesitation point, it ran fine after you get past a certain point at 5100 rpm's. What adjustments do i need to do now?<br /> walterV

 

[phatmanmike]

Re: 88 merc IL 6 115 compression

if you back your trailer in the water far enough, you wont HAVE to run it on the trailer with the engine. problem solved

 

[walterV]

Re: 88 merc IL 6 115 compression

the trailer part is not the answer. It still hesitates on accelaration. I have sent the boat to the shop three times and spent over $1100.00 and it still has the same problem.