1999 Johnson 200HP ocean pro - The Hull Truth

evilgli · 09-07-2009, 05:48 PM

ok, sorry but i will try to describe this as best as i can. i purchased this boat/engine in may of this year. engine started/idled fine and seemd to run fine on sea trial, topped out at 6200RPM. did compression test before buying and all cylinders were right at 100psi warm engine throttle wide open.. had ngk spark plugs in it.

after i purchased i installed NEW, champion recommended spark plugs, fuel filter in engine compartment, omc fuel primer bulb, racor water seperator filter, whole water pump kit, had 15X17 stainless OMC prop checked and redone. looking under cowling and you would say this engine has low hours, its very clean. all vacuum lines look great..VRO is still hooked up and operating as it should, only run XD30 OMC oil in engine.

now that this is out of the way, here is my concern.. engine starts and idles fine, a little cold natured but i have yet to see a OMC that isn't..after say 2 minutes it idles fine and will idle fine all day. i have had this engine in the water 6 times since buying, the last being this past sunday running 40 miles offshore of oregon inlet and trolling all day and running 40 miles back. well when pulling out of boat launch and no wake zone i go full throttle and when engine gets to around 2800RPM it seems like it boggs every so slightly and then clears up and runs all the way to 6200RPM no problem, back down to 4500RPM and cruise for a while no problem. run 40 miles out offshore between 4000 and 5000RPM and never a problem, had to vary engine speed due to sloppy conditions. get 40 miles out and start trolling which ended up around 1800 to 2000RPM and engine would surge slightly, almost like it's losing spark on a couple of cylinders just for a milli-second and then fine, (don't know if this is concern, just using example).. did this all day, if you go up to 2200RPM doesn't do concern.. about 7 hours later it's time to come home. go to full throttle and same thing seems to bog slightly around 2800 RPM and then is fine. ran about 5000 RPM most of the way back this time and had a shot of 6200RPM for say 10 to 15 minutes with no problems.

ok, so while i was trolling and it surged i tried pushing in on key to choke engine with no change from that, never tried messing with primer bulb, but i don't think it's fuel related, but i'm no expert. my question is, is this normal for this engine, (i also have a 1996 johnson 150 ocean runner, that doesn't do this at all)..i have heard of magnets coming loose from the flywheel, don't know if this is it? just wondering if some of you engine gurus have some input or seen this concern before..i will be using this engine alot offshore and want it to be right..this was on 7/22/2009

evilgli · 09-07-2009, 05:50 PM

this is what i did today..still pulling hair out

well. i'm about to take this engine to a shop to figure out what is going on with it... have not used it much since lat time i posted.. fuel tank was almost empty to i put 100 gallons of fresh fuel in it yesterday and 6 cans of seafoam.. ran the engine tonight on muffs for about 2 hours.. removed engine cover and what i would call (air filter box) so i could see in the carbs while running..well i would adjust throttle controls to run about 2500RPM (in neutral) and watch the engine surge up to 4000 RPM and then back down to 2500RPM, the whole time it sounded like it was loading up and occasionally i would see the port side middle carb have flames behind the butterfly....as stated before engine idles fine and revs and runs wot just fine..basically i'm trying to determine if this is a carb problem, or a ignition problem..don't have a manual and don't know which one to buy...use this boat offshore and want the engine right...i'm partly afraid to take to a shop because i have a feeling the first thing out of there mouth is going to be lets (rebuild the carbs)...great if this is the problem, but wasted money if not the problem and it seems that most shops think this is the cure for everything anymore..any help is much appreciated.

A1 Outboard · 09-08-2009, 07:07 AM

Flame coming from carb is normally an indication that cylinder is running lean. Lean could mean sync and link is off, carb is out of adjustment, or jets are plugged. Carbs may need to be cleaned. Quality of gas combined with ethanol causes problems. This is why many shops ask to clean carbs. You need to have a pressure and vacuum test done at WOT. This will show condition of fuel pump, filters, lines, antisyphon valve, and fuel tank pickup. Slow warmup can indicate that sync link and carb adjustment needs attention. Marking the flywheel for TDC on all cylinders and checking with a timing light might show a problem with the timer base. A good OMC tech should be able to find the problem.

evilgli · 09-08-2009, 10:05 AM

i see you have a location in portsmouth, do you do service work there? i'm not far from this location? thanks

A1 Outboard · 09-09-2009, 05:49 AM

We rely on local dealers to do service work. Our business is rebuilds.