1968 Mercury Merc 1000 100 h.p. Not Getting Up to speed, seems to bogg!

[donavonmercfreak]

Ok so i have a 1968 merc 100 hp that i am having issues with! When I start it with the muffs on its seems to run fine! when i start it up i have to choke it and hold key for a second but it always starts! As Long as i give it a little throttle it runs great, but if i leave it at idle, its seems to run for a while then just shuts off! Ok so heres my big question and issue! With the muffs it runs almost great i would say! It Starts up and runs at full rpms! sounds good as well! When I get it out to the lake it is a completely different story! It seems to take a bit so start, and when it does, it will only get up to about 10 miles an hour! (mind you it is on a 14ft crestliner) Even worse, when i use it(put it underload) at the lake it will go for about ten minutes and then just sputter out, and take a few minutes to get it started again! Motor has definately been taken care of....Looks great and is super clean! new plugs and wires and whole shebang! any advice and help is appreciated!

 

[gbrowne9]

Re: 1968 Mercury Merc 1000 100 h.p. Not Getting Up to speed, seems to bogg!

check the fuel pump ,when it,s bogging pump the bulb see if it piks up. if it does, replace fuel pump gaskets.other than that play with the idle mixter screws on the carbs. posibly running lean. adjust in 1/8 turn increments from 1 1/4 turns out from lighty seated.

 

[Texasmark]

Re: 1968 Mercury Merc 1000 100 h.p. Not Getting Up to speed, seems to bogg!

If it has been sitting up for a period of time....year or so, you probably have some varnish in the carbs which can clog the jets and deprive the engine of the fuel it needs to perform; like the (possibly needed) jet adjustment mentioned would do. If you don't feel like removing the carbs, doing a "decarb" (see archives) or two would help. Would also loosen up any stuck rings which could help with the problem if any are gummed up.

On tweaking the jets, have to ask yourself why? Was it running ok the last time someone had it out.....a year ago if that's the case? Or have you already been into it diddling the carbs and didn't get the low speed jets opened far enough?

Mark

 

[Faztbullet]

Re: 1968 Mercury Merc 1000 100 h.p. Not Getting Up to speed, seems to bogg!

Run a compression check...and it will run great on hose with no load.

 

[donavonmercfreak]

Re: 1968 Mercury Merc 1000 100 h.p. Not Getting Up to speed, seems to bogg!

If it has been sitting up for a period of time....year or so, you probably have some varnish in the carbs which can clog the jets and deprive the engine of the fuel it needs to perform; like the (possibly needed) jet adjustment mentioned would do. If you don't feel like removing the carbs, doing a "decarb" (see archives) or two would help. Would also loosen up any stuck rings which could help with the problem if any are gummed up.

On tweaking the jets, have to ask yourself why? Was it running ok the last time someone had it out.....a year ago if that's the case? Or have you already been into it diddling the carbs and didn't get the low speed jets opened far enough?

Mark

i am really new to the whole boat thing and am not too versed in the whole carb adjustment thing! What is the best way to go about it and are there any places or ways to get a step by step! Thanks again

 

[Texasmark]

Re: 1968 Mercury Merc 1000 100 h.p. Not Getting Up to speed, seems to bogg!

Upper right corner of this thread is an ad for Seloc manuals. Get one read through the process and if you get stumped get back on here and we'll help. The manual is well worth the money. The decarb is in the archives.

Mark