thefishingfreak
Seaman Apprentice
- Joined
- May 12, 2002
- Messages
- 46
it's a 1990 250 vx76 carbed,oil injected.<br /><br /><br />i melted a piston about a month ago.no apparant reason for the meltdown,i think a ring broke?hence the little pieces of ring forcefully imbedded in the piston.<br />anyway,,,<br /> i did the- rebuild the powerhead thing,new piston, rings, head, honed out the sleeve, etc...<br />she ran mint, tooled all over the place. no sweat.<br />other day were out, i'm toolin' along at 5000 rpm's for an hour, i crack the throttles a tad more then she starts cutting out??<br /> <br />fuel pumps are new last season. <br />when they went bad last year,,,,,,,<br /> i got the "wha-wha-wha-wha-wha-wha" very constant rpm raise and drop, say 200 rpm's.<br /> <br />now,,, completly different kind of cutting out.<br />"wha-buh-buh-buh-wha-buh-wha-buh" pinned the thing to the boards, she won't stay running. slowly comes down to a painfull idle, then dies. no chance in heck to fire it up again.<br /> <br />we get back to the slip,<br />crank,buh-buh-buh.<br />crank,buh-buh-buh.<br />crank,buh-buh-buh.<br />over and over, you could do it a hundred times same thing.<br /> starts, runs for maybe six or seven revs, then dies.<br />switched brains- coil packs- plugs from the other engine. no dice.other engine still runs mint.<br />disconect fuel pump line to carbs, tons of pressure there.disconect cold start lines to cold start injectors, tons of pressure there. injectors are pulsating, like they should. <br />i say screw it and go home.<br /> <br />i gown today,<br /> same thing, won't start.<br />i blast the carbs with wd40 {only flamable thing i could find}--- brmmmmm!!!!!! bingo!! fires right up. <br />she runs mint,,,,,idled for 1/2 hour, cruised over to the fuel dock, shut it off and fired it up a couple times, schweet, problem solved.<br />NOT !!!!<br />we start heading out,, get all the way to the inlet {1/2 hour} at 2400 rpm's,,,gets up on a plane no problem,, run for 20 minutes at 47,48,49,5000 rpm's like a champ,no sweat, then same thing.<br />wha-buh-buh-wha-buh-wha-buh-buh-buh-painfull idle-then dies!!!!!<br /> what the???<br /> crank over,,, same thing,,,, runs for two seconds-dies. over and over again.<br /> <br />i'm friggin' dumbfounded???<br />when you start them cold, the cold start injectors fires extra fuel, and the timing retards 7 degrees atdc, to make it eisier to start, then when they get warm, timing goes back to 7 degrees btdc and the injectors shut off.they also cut out alternating cly's when giong slow{i'm thinking the brain does this? hence the brain-coil packs-plugs swap}.<br />there's a glass jar in-line with the fuel, and there ain't no gunk or water in there.<br />i havent touched the water separators, but i figgure with the glass jar i would see a problem in the fuel.and,,,<br /> the other engine runs mint, never skips a beat with the old water separators that take fuel from the same tank.<br />help..... i wanna go fishing.<br />mike
<br />cleaned out the glass{plastic} jar,,,a couple little chunky things on the bottom but nothing that could get past the fine mesh screen and into the carbs.<br />blow everything out{with portable tire tank}, all's good.<br />bolt the carbs back on, adjust all the linkage.<br />wont start,,but it's better than it was, get maybe 15 revs before it dies.<br />i blast the carbs with carb cleaner,,"brummmmmmm"<br />fires right up.<br />ok, let it run for ten-fifteen minutes. seems to idle to high. so,,,,, i'm thinking to much fuel{cold start is still on???} i go to disconect the red plug for the cold start pump. AHHH-HAAA!!! black ground is falling out of the conector! i found it!!!!<br />re work it to fit back in nicely.<br />all seems good.<br />i get thru the inlet and really let her have it!<br />schweet,,runs like a champ!!<br />i do a victory lap arround the harbor for an hour, all's well.<br />then same sh*t!!<br />starts cutting out!<br />but this time is different, she dosen't die! stays running coughing and farting{idles nice}.<br /> rip the cover off, i'm like i got you now!!! stinky, burning eyes{running too rich}!!!<br />i'm thinking cold start pump ground wire, nope. it's still good.<br />i disconnect the throttle linkage, give it a couple cracks to try to get some rpm's. sounds like it's missfiring on one cylinder.<br />brm-baha-brm-pop-brm-bha.<br />i disconect the cold start pump red plug. give it a couple cracks brmmmmmm-brmmmmmm.nice!!<br />schweet, i found the problem??<br />so i try to run with the cold start fuel pump disconnected, runs great,,,, got no power!, but runs great.tops out at 2500 rpm {if i help it with the other motor}.<br /><br />why won't it get any power with that elictric motor unplugged?<br />i thought it was only for cold starts?<br /><br />anyway, thats whear it stands now.<br />mike