OMC Guru's---Dhadley, Walleyehead, anyone....

[Basscat 1]

Re: OMC Guru's---Dhadley, Walleyehead, anyone....

Tysidor, we can only offer suggestions on what to do next based on what you have told us, however it is up to you if you want to pursue this or take it into a dealer.<br />Most but not all dealers will tell you that 5000 rpms at wot on a 1977 engine is ok and probably wont do anything to fix this.<br />Try what walleyehed says and pull the bottom jets and check the numbers.<br />As far as the timing jumping up and down at wot, that shouldnt happen either.

 

[Blueclaw]

Re: OMC Guru's---Dhadley, Walleyehead, anyone....

If I'm not mistaken, OMC recommended rejetting carbs used at 3000 ft or better.<br /><br />I'd pull the flywheel and check the timing base for wear. Ring out the base and see if the ohms fluctuate when you wiggle the base plate. Check your flywheel magnet and triggers coils also or does that older model use points for your trigger? <br /><br />What color are your plugs when you run at WOT then shut down and check them. Are they burning clean or loaded up/wet? Should burn light tan/dry. Can't check them if you idle, has to be from a long WOT run.<br /><br />the other thing you need to do is lower your idle. You'll tear up your lower unit banging it into gear set at 850 rpms in gear. 650 rpms in gear is what you want.

 

[walleyehed]

Re: OMC Guru's---Dhadley, Walleyehead, anyone....

Unless everything else is perfect, it won't Idle at 650 very long. I have boyesen reeds in my V6, and I had a hell of a time getting to 600...3 idle bleed orfice changes...and, ya gotta pull the bottom carb to change those...700 is more common. as rough as mine is at 600-650, I can't imagine how rough it would be without boyesens at 650...

 

[tysidor]

Re: OMC Guru's---Dhadley, Walleyehead, anyone....

Well last night I didn't have very long to work on it. <br /><br />I backed my trailer back in to check the timing jumping around. First off, it was more consistent on the #2 cylinder then it was on #1. I still jumped around, but not as much. It would read anywhere from 26-32 degrees. The average would be around 28-29. Every now and then it would jump all the way down to 0-5 degrees then come back up. Also twice it stopped blinking for about a second then started again. I don't know if my timing light isn't working right or maybe my cylinders are not firing consistently. The way I checked spark at WOT was to hook the timing light upto each cylinder and make sure they were blinking. Is there another way I should check this? The timing light is a (Snap-On) so it's not a cheap piece of junk. <br /><br />As far as checking the jet sizes. I got as far as pulling the air cover off and didn't have time to pull the jets. I plan on doing that today. I did come across an OMC jetting chart for different elevations. It reads like this 0-3000 (61C), 3000-6000 (59C), 6000-10,000 (58C). So at least I have something to compare my jet sizes against. <br /><br />As far as checking ohms, I really don't have a clue how to do that. I wish I knew more, but that's what I am depending on you guys for. I will check my plugs at WOT and see what they look like.<br /><br />I will let you guys know what I find out.

 

[Basscat 1]

Re: OMC Guru's---Dhadley, Walleyehead, anyone....

One other feild method of checking each cylinder would be to start it up and pull one plug wire off at a time and listen to the engine. If it makes a noticable change or sputter, then that plug and cylinder is firing.<br />Another method. Take the cover off and start the engine at night. Look for blue or red sparks or arks around the plug wires or any ignition part.<br />The timing light (Snap On) is a good one, but possibly with engine running, plus the movement of timing light, maybe you just didnt have it hooked on the battery very good. ?<br />By the way, dont forget to check the fly wheel key and check everything (ignition wise) under the flywheel why you have it off.<br />I have seen worn fly wheel keys cause timing problems.

 

[Blueclaw]

Re: OMC Guru's---Dhadley, Walleyehead, anyone....

I looked up the 77 200 ignition and it seems your model uses points to trigger the spark.<br /><br />I'm thinking the points are out of adjustment causing the timing to fluctuate and miss.<br />Pull the flywheel and check your points.

 

[Basscat 1]

Re: OMC Guru's---Dhadley, Walleyehead, anyone....

Points? I dont think so.<br /> web page <br /><br />I would still pull the flywheel and check the ignition system.

 

[tysidor]

Re: OMC Guru's---Dhadley, Walleyehead, anyone....

Hey everyone. I appreciate all of the comments and advise. I am out of town and will be for the next 3 days. I will go back to work when I get back.

 

[Basscat 1]

Re: OMC Guru's---Dhadley, Walleyehead, anyone....

Keep us updated, I think you got the record for the most replys on one thread.

 

[Dhadley]

Re: OMC Guru's---Dhadley, Walleyehead, anyone....

Walleyehed, will your motor not idle lower than 600 because of altitude?

 

[Blueclaw]

Re: OMC Guru's---Dhadley, Walleyehead, anyone....

this is where I saw the point setup with that motor.<br /><br /> http://www.maxrules.com/fixomccdi15.html

 

[jy118lfd]

Re: OMC Guru's---Dhadley, Walleyehead, anyone....

Tysidor One thing about your timing light. I have a couple snap on advance lights both the manual dial and computer controlled one and I get the timing jumping around like that. I had to dig out my dads old sears light the one you take the wire off the plug and put this between the plug and wire (not inductive). My timing with this is dead on, never moves except for advance of course. I think the timing jumping around might be your timing light you might try to get an older light and try it again.

 

[Dhadley]

Re: OMC Guru's---Dhadley, Walleyehead, anyone....

No recreational OMC V6 outboard ever had points.

 

[walleyehed]

Re: OMC Guru's---Dhadley, Walleyehead, anyone....

DH, I'm not sure about the altitude thing on Idle...it's never bothered any V4's or tripples..<br />People thought I was nuts when I told them I could pull the Idle down to 400 on my 115 and run smooth....until I showed them. It liked about 500 best, and I gave that credit to the Boyesens..<br />The 200....I don't know, but it sounds like a top-fuel at Idle...like it's not "real sure" which way to turn...I am getting an occasional sneeze, so I'm going back one step richer on Idle bleeds.<br />If the price of fuel goes up anymore, I'm going back to a 90 or something I can afford to run.<br />Your comment is also leading me to look into my tach.....it's not OMC....My system check tach went with the 115 as part of the deal.<br /><br />As always, you may have opened my eyes to something I have completely over-looked.

 

[Dhadley]

Re: OMC Guru's---Dhadley, Walleyehead, anyone....

I was just curious. My cf idles at 500 or slightly below and does not have Boyesens. But this is sea level and I wasnt sure what effect that had on idle.<br /><br />Your concern about the tach is something we've seen before. OMC / BRP tachs seem to be very accurate. We had issues with other brands before and the factory actually told me they consider a tach accurate if its + / - 5%. At 6000 thats 300 rpm and not acceptable (to me). It was driving us nuts on a tripple engine deal. That company did say they were trying to reduce the + / -.

 

[tysidor]

Re: OMC Guru's---Dhadley, Walleyehead, anyone....

Sorry it has taken me so long to get back to everyone. I was out of town for a while and when I got back I was swamped at work. <br /><br />I pulled my high speed jets and they were the factory size 61C. I ordered in some 59C's that just got here today. I will put them in and see if that helps at all. The marina insists that I am crazy and will burn up my engine. The good news is that I trust you guys alot more then them. <br /><br /> http://www.ishopmarine.com/ishop/js...~A0000021~M0011388~M0011402~M0011404~C0146839 <br /><br />I also noticed my exhaust outer cover (#38) was missing some screws. I proceeded to take it apart and both gaskets (#39)(#34) were shot. I put it back together as it was. I have both gaskets on order. Maybe that has something to do with my problem. Either way I figured they needed to be replaced. <br /><br />I will also recheck timing tonight with a completely different timing light and see if it is more consistent.<br /><br />If I have time I will pull the fly wheel and check everything. I have never checked my stator. Hopefully I can get all of this done tonight and still have time to run it. I will post back and let you guys know how everything goes.

 

[Basscat 1]

Re: OMC Guru's---Dhadley, Walleyehead, anyone....

While checking your stator count the number of poles like in the picture below. Yours will probably have a different count.<br />Just to make sure.<br /><br />

 

[tysidor]

Re: OMC Guru's---Dhadley, Walleyehead, anyone....

Well I didn't get as far as I had hoped before it got dark. I got my new jets put in and that was about it. Hopefully I will be able to take it out today and see how it runs. <br /><br />BassCat 1 -- I will be sure to count the poles on my stator when I pull it. <br /><br />Anyone have any idea if those gaskets I mentioned earlier could have been causing a problem?

 

[Basscat 1]

Re: OMC Guru's---Dhadley, Walleyehead, anyone....

Leaking exhaust cover gakets can cause the engine to over heat. You need to repair them soon as possible.<br />We are going to break a 100 replies...

 

[tysidor]

Re: OMC Guru's---Dhadley, Walleyehead, anyone....

I took it out last night. First I used the other timing light. It was right on at 28 degrees. It didn't flicker all over the place like my Snap-On light. So now timing is 100% for sure at 28*.<br /><br />When I ran it WOT I maybe gained 100-150 rpms. So the jets did help a little bit. It also seemed to be a little more jumpy out of the hole. So the jets helped, but did not fix the problem. <br /><br />I didn't have time to pull the fly wheel. Hopefully I will be able to get to that when I receive those exhaust gaskets. <br /><br />Wow this thread has gotten really long. I am so thankful for all of the advice and knowledge that has been given to me throughout this thread. Thanks everyone and keep the advice coming.