1985 Johnson 185 No Hole shot

[nightimefishn]

Hello all, I just picked up a 1978 200CCP Aquasport with a Johnson 185HP. 110 in 5 cylinders and 105 in one. I have cleaned carbs, changed plugs and wires, new impellar and lower unit oil recently just changed.

Boat is about 1800lbs with no fuel or passengers.

I am not getting any hole shot at all. I have to take a look at the prop to double check. Sorry I do not have RPM's @WOT (was too excited to get her on the water over the weekend and forgot)

She runs real strong, but I am concerned about the hole shot. It almost seems like she is trying to catch up, I will have the throttle full and it just moves along and gradually picks up speed. I would think she should scream out of the hole.

Suggestions? Fuel pump, wrong prop?

I will post back some numbers when I get back out. Havent hooked up gps yet so will post mph and rpm's when I get her out.

Thanks

 

[emdsapmgr]

Re: 1985 Johnson 185 No Hole shot

110 compression is about normal. You may want to run some Bombardier Engine Tuner through the powerhead and see if the low cylinder will come up a little. An overpropped engine will definitely cause a poor holeshot. You need to check the rpm's at top end-if the engine will rev to 5700 you probably have the correct prop on the engine. Make sure you have spark on all 6 wires when running-an inductive timing light will show what each plug wire is doing when you are running under load.

 

[nightimefishn]

Re: 1985 Johnson 185 No Hole shot

Thanks I think spark is fine. I am now looking in to a fuel issue. Once I get her back out this weekend I will post some numbers.
Will try the engine tuner also this weekend.

Thanks

 

[SparkieBoat]

Re: 1985 Johnson 185 No Hole shot

you "think" the spark is fine? or you tested your spark with a spark gap tester and know that your coils are strong? Anyway with out RPM, prop and speed data cant really even make a guess there. you also may want to clean/rebuild carbs, check all fuel lines and do a link and sync. and check timing. and a new set of champion plugs.

 

[nightimefishn]

Re: 1985 Johnson 185 No Hole shot

Sorry for the half ***** response.
Spark was tested, strong spark on all coils, new plugs, wires, carbs cleaned, new fuel lines, timing dead on. My mechanic is going to do a fuel pump pressure test this weekend. I will get numbers up once I get out again.

Prop is a 14 1/2 x 19 Stainless

Thanks all for your replies.

 

[SparkieBoat]

Re: 1985 Johnson 185 No Hole shot

thats a big heavy boat..my first instinct is that you need a 15 or 13 pitch prop... which ever will get you to 5500 RPMs under a full load at WOT
It does depend a lot on a the hull design/condition. I had a 17.5 light boat with a 150 that was over pitched with a 17..had to drop down to a 15...a 13 would not be out of the question for you. but first make sure your motor is ok, I doubt its the fuel pump. and test with a working tach and get your numbers. it will raise about 200 rpm per inch drop in pitch..so if your at 4800 RPM topped out, you want 600-800 more RPMs drop about 4 inches to a 15..just an example. always best to borrow a prop and see how it does before you buy one, if you can.

 

[SparkieBoat]

Re: 1985 Johnson 185 No Hole shot

most 20' boats are rated for a 200 or 225. my guess is your slightly underpowered, but with the right prop you should get decent preformance.

 

[nightimefishn]

Re: 1985 Johnson 185 No Hole shot

Thanks, Yes boat is 1800 lbs I think.
Rated for 200, but I just picked it up. Hull is in great shape. I would love to throw a 225 on her but limited funds for now. I know my local prop guy, he should let me borrow a couple and see which one I like. I think I want to try a 15, will let you know.

Cant wait for this weekend already....

Thanks again

 

[nightimefishn]

Re: 1985 Johnson 185 No Hole shot

Was able to get out yesterday and run the boat real good for a couple hours.

I am at 4500 ROM's @WOT 29 KTS according to GPS.

Boat felt reals trong...

 

[SparkieBoat]

Re: 1985 Johnson 185 No Hole shot

what pitch/diameter prop??..you need about 1K more RPMs..you are overloading your motor.

 

[nightimefishn]

Re: 1985 Johnson 185 No Hole shot

14 1/4 19pitch

 

[SparkieBoat]

Re: 1985 Johnson 185 No Hole shot

if your tach is correct I would suggest trying a 15 pitch prop..should get you over 5K maybe even try a 13

 

[wires38]

Re: 1985 Johnson 185 No Hole shot

I had a 19 grady (2100 lbs) with a 175 johnson. same prop you mention, the hole shot was outstanding. Its definitely enough motor. There might be something the motor does to advance the timing at wot thats not happening?
just a thought , good luck!

 

[emdsapmgr]

Re: 1985 Johnson 185 No Hole shot

No wonder the hole shot is so poor. You are lugging the engine by only running it at 4500. Lugging creates excess internal heat and poor economy. You are 250 rpm below the factory recommended rpm range of 5250-5750. You are at least one prop size too large. That engine is made to run up to 5750 on top end. You should prop it to run there. A 17 is still probably too much prop.