Lost and Need help

[mattsylvan]

hi i have 1980 75hp johnson outboard and well i have hit a brick wall. my motor still bogs at wot. i have had it worked on a an omc repair shop this is the work i have had done and didnt change anything new throttle cable, new lower unit, powerpack, compression good in all 3 cyclinders, they replace the jets and they said it is worse with the right jets in it (currently has wrong jets in it) then they said they have no idea what wrong. i feel lost with this motor has anyone encountered the same problem?

 

[rickdb1boat]

Re: Lost and Need help

Have they checked out the fuel pump?

 

[Mas]

Re: Lost and Need help

Plug wire grounding out?

Prop slipping?

Air leak in fuel line?

MAS

 

[oldrudedude]

Re: Lost and Need help

When you say "boggs at WOT",what do you mean? Bocks and sputters, or will not wind out to top rpm?

You say the shop changed the jets. Did they put in oversize? What was their reasoning for doing that? Did they link/synch it?

 

[kenmyfam]

Re: Lost and Need help

I think i would be finding a new repair shop.

 

[mattsylvan]

Re: Lost and Need help

the prop is not slipping the spark plug wire is not grounding out (that i know of) havent check fuel pump, it wants to die at full throttle, they put the jets in that where supposed to be in it when it came from the factory and they said it made no difference. on the repair bill they said it arrived with #32 jets production was #61 and i dont think there is aire in the lines because the squeeze pump holds its prime

 

[emdsapmgr]

Re: Lost and Need help

When the engine it at full speed and starts to bog, try priming the fuel hose bulb. This will force fuel into the carb bowls. If the engine picks up and runs fine while priming the bulb, you may have a weak fuel pump.

 

[mattsylvan]

Re: Lost and Need help

i have to choke the motor to get it to full throttle last time i had it out i didnt even get full throttle, but is there something to look for when checking those?

 

[Faztbullet]

Re: Lost and Need help

It sounds to me the tech working on engine doesnt know difference between idle jets and midrange jets. The idles will be in the 30's the mid range in the 60's and high speed in the mid 50's. Tapping choke to make engine run on top end is a fuel problem (lack of) due to : low pump pressure,air leak,restricted or crimped fuel line,float levels set to low and dirty high speed jets.

 

[mattsylvan]

Re: Lost and Need help

i dont know if it matters or not but i looked at the 3 carbs and the numbers on all three were 326951 but i looked up the #61 jets on the evinrude site and it said used only on upper and lower carb 75 models only. the number that i need to get the right jets would be the carbs though right?

 

[oldrudedude]

Re: Lost and Need help

the number that i need to get the right jets would be the carbs though right?

What does this mean?

 

[mattsylvan]

Re: Lost and Need help

im just trying to find out if the number stamped on the body of the carbs have any use in finding out what the right jets are

 

[emdsapmgr]

Re: Lost and Need help

You have an unusual carb set on this engine. What further complicates your efforts is that the carbs changed midway through the production year, so you really need to know what the vintage of the carbs is. The carb jetting is pretty clear in the Bombardier parts list, found on the web at: epc.brp.com. You need to know if the engine is a 20" shaft, or the short 15", then check the parts list. The parts list does indicate factory part numbers for the carbs which should match those stamped on your carb bodies. These carbs did have bogging issues around this time (model year) period and may be why OMC changed them midyear. I had some different carb issues on a later 3 cyl 60 and wound up buying a used set of carbs for a 70 off ebay. Problem solved- rather cheaply. If you plan to upgrade to newer carbs, keep in mind that you may have a choke issue, as 83 and later models don't use the choke butterflys.

 

[mattsylvan]

Re: Lost and Need help

good to know i checked brp and found nothing on these carburators