'89 150 BlackMax idle/start problem... - Page 2

reyb · #11 07-13-2009, 05:57 PM

Quote:

Originally Posted by spareparts

what kind of tach are you using to set the idle rpm, the one in your dash is probably not accurate enough at low rpm, I set the idle rpm usually by ear if i don't have my shop tach handy. I set it high enough where it will idle in gear, but when I pull it out of gear and back in, the boat doesn't lurch and you don't have a big clunk when shifting, try going from fwd to reverse, as long as it stays idling, adn it doesn't shift too harsh, you should be ok

Yeah, just referencing the tach on the dash. Again, it idles fine after it the motor has warmed up for about 10 minutes. I believe it's around 750 - 1000 and I can shift into gear with pretty smoothly.

spareparts · #12 07-13-2009, 08:22 PM

go back and sync the carbs, pull the idle stabilizer off, adjust te pickup timing to get it to idle. Have you base lined it? Compresion test, spark check?

HookedOnMarsh · #13 07-13-2009, 08:30 PM

Hope you don't have the same problem I have. I pulled my hair out trying to find out what was going on with my motor. It was hard to start cold, wouldn't idle until it warmed up real good, would die when put in gear sometimes. I think I found my problem when I noticed a few drops of water on the #3 sparkplug. Pulled the head and found the head gasket had blown and water had been seeping into the cylinder for some time. Long enought o do some serious damage to the water-jacket side of the cylinder. Have cleaned it up real good and am filling in the missing bit of metal with JB Weld and ordering a new head gasket. Hopefully I can fix it. Don't just go pulling your heads though, I broke one and had to EZ it out. Was not fun and sure don't want to pull the other head to examine.

reyb · #14 07-14-2009, 08:52 AM

Quote:

Originally Posted by spareparts

go back and sync the carbs, pull the idle stabilizer off, adjust te pickup timing to get it to idle. Have you base lined it? Compresion test, spark check?

About the only thing I've done that you've suggest is to do the compression check. I don't recall the numbers but will do it again. I do remember that all the cylinders were relatively the same. I'll be getting a manual but as of right now I don't know the procedure for doing the other things you suggested.

Hmmm, after replying to Hook's comment could the syncing of the carbs, pulling off the idle stabilizer and adjusting the pickup timing be affected by the motor being warm?

Thanks,

Rey

reyb · #15 07-14-2009, 08:57 AM

Hooked,

I don't recall seeing any kind of water on the spark plugs. Since my motor seems to idle after it's warm, it makes me wonder what it could be.

bigshrimpin · #16 07-14-2009, 02:51 PM

Quote:

Originally Posted by spareparts

go back and sync the carbs, pull the idle stabilizer off, adjust te pickup timing to get it to idle. Have you base lined it? Compresion test, spark check?

Rey - Start here. If you are concerned about a blown headgasket . . . the compression test will reveal that . . . also you can see water intrusion by reading the plugs. Water will steam clean them and they will look brand new. Honestly I think you just need to adjust the pickup timing so that it idles. One more question . . . do you have the giant 40 voltage regulator on your motor? Spares is a skilled factory certified Mercury Mechanic with many years of experience . . . consider yourself lucky to get his free advice.

reyb · #17 07-14-2009, 03:32 PM

"pickup timing" I'll definitely be googling that as I don't know what that refers to. :) I don't know if I have the 40v regulator. Module wise I have the ~3"x5" black box located near the rear or the engine on the throttle linkage side and just above that on top of the engine there is a ~2"x3" module with 2 wires going to it. I'm still trying to locate a Clymers manual locally but if I can't ,then I guess eBay it is. Btw, I appreciate all the input I get on this...thanks so much!

Rey