No guts, need more help with J120 power issues. (* RESULTS UPDATE*)

[alden135]

Re: No guts, need more help with J120 power issues. (* RESULTS UPDATE*)

Goodoleboy, I believe you about the timing. The tb does have free range of motion. I have never messed with the wot timing, so would that most likely account for that much rpm loss? Would the spark dwell adjustment knob being out of adjustment effect the wot rpm? I have not touched the adjustment for the msa screw which the timer base stops at.

 

[alden135]

Re: No guts, need more help with J120 power issues. (* RESULTS UPDATE*)

I think part of my problem is info overload. I have read too many posts about power loss. I keep changing directions from ign. to fuel to props etc.

 

[Dhadley]

Re: No guts, need more help with J120 power issues. (* RESULTS UPDATE*)

What you refer to as the "spark dwell adjustment knob" is actually the idle adjustment. It has no effect on top end.<br /><br />If you havent checked the timing, we should do that. In addition mark top dead center on the flywheel for 2, 3 and 4. We usually use white out and dont forget to write the number of each cylinder by each line.<br /><br />We check the timing with the boat on the trailer backed down the ramp so we can run the motor with a load on it. After you check the timing, hook your timing light to each cylinder to make sure we're not losing spark.

 

[alden135]

Re: No guts, need more help with J120 power issues. (* RESULTS UPDATE*)

My boat is in Maine so I won't be able to get to it until Sat. Is there anything else I should check at that time before I post back?

 

[Dhadley]

Re: No guts, need more help with J120 power issues. (* RESULTS UPDATE*)

Yes, now that you mention it -- I noticed you said you disassembled the carbs and they are clean. Did you soak them -- and the throttle bodies too? If not, that would be a great idea. And, obviously, install new kits.

 

[Goodoleboy]

Re: No guts, need more help with J120 power issues. (* RESULTS UPDATE*)

Alden...What DH just said is the correct and last check on WOT timeing. Joe Reeves has said after his method it should be checked in this manner.<br /><br />While your in the drive way its good to do it Joes way.<br /><br />1.Remove all spark plugs and hook up spark tester.<br /><br />2. Open throtel full open, Wire rubber timer adjuster to stop if nessary.<br /><br />3. with timeing lite hooked to num.1 wire. Set timeing 4* less than what the manual calls for. One turn one the adjuster will move timeing 1* aprox.<br /><br />For instance if it calls for 28*BTDC set it at 24*BTDC, the electronics makes up the other 4* when its running at WOT.<br /><br />Iam saying this from memory. Mabey you wana do a search on WOT timeing and print it out.<br /><br />Then at the ramp do as DH suggested. But make sure you are tied to the trailer real good and stout.<br /><br />Should have somebody else with you to shuter down just in case. Or at least a string tied to dead man kill switch.<br /><br />Good Luck!

 

[alden135]

Re: No guts, need more help with J120 power issues. (* RESULTS UPDATE*)

Originally posted by Dhadley:<br /> Yes, now that you mention it -- I noticed you said you disassembled the carbs and they are clean. Did you soak them -- and the throttle bodies too? If not, that would be a great idea. And, obviously, install new kits.

My manual and the gallon can of carb cleaner both said not to soak plastic carbs. I sprayed carb cleaner through all just to make sure things were clear. Are you saying I can soak plastic carbs? If so then I will.<br /><br />Lee, Thanks for the info. I read Joes method a while back and will use it. I will have to disconnect the fast start before doing so though.

 

[Dhadley]

Re: No guts, need more help with J120 power issues. (* RESULTS UPDATE*)

We soak them in Engine Tuner. It only takes about an hour to clean the worst type crud. It works pretty quick.

 

[alden135]

Re: No guts, need more help with J120 power issues. (* RESULTS UPDATE*)

Did a search on disabling quick start. Some posts say to disconnect wht/blk wire at port head and others say to disconnect and ground that wire. Which one is it? Ground the wire or not? Thanks to all who have helped on this thread. Your time and knowledge is appreciated.

 

[Solittle]

Re: No guts, need more help with J120 power issues. (* RESULTS UPDATE*)

When you clean the carbs make sure you blow them out with high pressure compressed air - not the rattle can stuff. Pay particular attention to the small passages.

 

[alden135]

Re: No guts, need more help with J120 power issues. (* RESULTS UPDATE*)

Thanks to Dhadley, Goodoleboy, Walker, Solittle, Almost Retired Again, for all your help. I put the cleaned carbs back on, checked the timing, and changed to a 13 3/4 X 15 prop. My boat is now achieving a more respectable speed and is no longer lugging. My tach must have something wrong with it because it now only goes to 3K even though I hear the motor reving higher. That's a problem I'll work out later. Thanks again for all the help!

 

[Dhadley]

Re: No guts, need more help with J120 power issues. (* RESULTS UPDATE*)

What was the timing set at?

 

[alden135]

Re: No guts, need more help with J120 power issues. (* RESULTS UPDATE*)

Dhadley, the timing was 19 BTDC. I changed it to 18. I checked it on the water at wot.

 

[Dhadley]

Re: No guts, need more help with J120 power issues. (* RESULTS UPDATE*)

Thats cool. The thing about the tach is interesting. Let us know how you make out.<br /><br />Good luck, keep us posted!