Dhadley........Talk to me!!!!!!

[4link1955]

I have a 1973 115 Evinrude that I built a 1977 115 powerhead for. I bored it .030" over and used a set of Weisco Pistons in it. I'm using the 135 carbs, 135 heads, and the 135 exhaust bubble on this motor. I was wondering how much timing can I safely run with this motor to get the most power out of it without burning a piston? I can't remember the cranking compression on it right this minute. I will check it this afternoon and post it. I'm the one that can't seem to get this motor to turn any more than 5000 rpms. I have raised the motor one more hole and will try it out this weekend.<br /><br />Also,<br />I have noticed you have been talking about that you used to run these older crossflows and turn them 6000 plus rpms. What did you do to them to get them to turn like that? Are there any mods that I can do that will give me alittle more performance out of this motor without spending alot of money? I just wish my motor would turn more rpm's, I know it would run alot faster if it would. What do you think about putting some vents in the cowl to let the motor breath?<br /><br />Thanks in advance:<br />Jason

 

[4link1955]

Re: Dhadley........Talk to me!!!!!!

Sorry about that guys......wrong forum!!! I keep forgetting not to post repair stuff in this forum. <br />Jason

 

[Dhadley]

Re: Dhadley........Talk to me!!!!!!

I wouldnt run any more timing than the (OE) manual calls for. 28 I think.<br /><br />Let us know what raising the motor does.

 

[4link1955]

Re: Dhadley........Talk to me!!!!!!

Dhadley,<br />What do you think about venting the cowl to let the motor breath better? I just don't see how these motors run like they do and be closed up so tight under the hood. I'm trying my best to get more rpm's out of this motor.<br /><br />Thanks:<br />Jason

 

[Dhadley]

Re: Dhadley........Talk to me!!!!!!

Run it once with the hood off. It may pick up 100 or so. I've taken the cover off thats under the bottom carb but it never seemed to do much. We've fooled around with the hole in the hood (by the hand hold) but again -- didnt seem to do much.<br /><br />We've closed the complete hood and pan area and hosed in cool air too. Same thing.

 

[kas]

Re: Dhadley........Talk to me!!!!!!

You may be turning as high a rpm as you will get with the diameter & pitch prop you have. There is more to life than high rpm's. I have a 1995 70 hp that will turn 6600 with a 13x21x3 18' john boat about 1500# and can't get down to the 5400 I am suppose redline at. I need more prop ($$$.$$). I don't anything else to help you at this time.<br />Good Luck!

 

[Hooty]

Re: Dhadley........Talk to me!!!!!!

I've got a '76 200hp V6 'rude that turns 62k on a regular basis. I just don' keep it there long.<br /><br />c/6<br /><br />Hooty

 

[Dhadley]

Re: Dhadley........Talk to me!!!!!!

Why not Hooty? Run outta lake?

 

[Joe Reeves]

Re: Dhadley........Talk to me!!!!!!

Hooty...... 62k ?<br /><br />I had a friend that bragged about that, untill one day.... the flywheel came flying through the shroud with (as JFK would say) Great Vigor! He said it was quite exciting!

 

[chilifriedpork]

Re: Dhadley........Talk to me!!!!!!

Wouldn't it be 6.2k?<br /><br />Either way that's high performance. I guess more wear and tear on the engine at those rpm's but, then again as long as you aren't pushing it above reconmended rpm's then it would be designed to run that way.<br /><br />I don't think flywheels should "fly" off. I prefer them attached to the engine. I hear it helps!!! LOL

 

[Hooty]

Re: Dhadley........Talk to me!!!!!!

6.2k (62c)<br />6.2k is a lot more believable ain't it. I've been doin' some re-proping and the engine turns that with a 24" Raker and hums like a sewin' machine. I really like the way the Raker handles too. <br />I have been sorta runnin' out of lake. The winds been gusting to 25mph so I have to run beside the dam and it's only a mile or so long and then I've gotta shut down.<br />I bet losing a flywheel would cause some serious tobacco stains.<br /><br />c/6<br /><br />Hooty

 

[4link1955]

Re: Dhadley........Talk to me!!!!!!

Dhadley,<br />I checked my compression last night and all 4 cylinders are dead on 150#. I have been told two different numbers as far as the timing. I have been told by two or three different people to run 28 degrees and some have told me 24 degrees. I'm scared to run too much but I want the most out of this motor too. What do you recomend? Also, is 87 octane gas still ok for compression numbers like that?<br />Thanks again:<br />Jason

 

[Dhadley]

Re: Dhadley........Talk to me!!!!!!

Heres what we do -- after a rebuild we set it at 24. After the break-in we test it to full rpm which is as close to 5800 as we can get. Then advance the timing to 26. Test again. Most times you may see a small improvement. Go to 28 and test. If there was no difference then back it down to 26. <br /><br />It really depends on the boat. A pad bottom boat or a tunnel boat will respond to small increases in torque. <br /><br />You may simply be over carb'd. I would try the 115 carbs at some point.<br /><br />Good luck!

 

[4link1955]

Re: Dhadley........Talk to me!!!!!!

Dhadley,<br />I tested the boat this weekend since I raised the motor up one more hole. I'm up as far as I can go with the motor right now without doing some modofications. I picked up 200-300 rpms by doing this. I'm still not where I need to be (5400-5500). The motor was not cavitating at all, should I go up some more with the height? I ran the motor without the hood one time to see if it made any difference, it ran the exact same thing. I still haven't decarbed yet, I'll probally do that this week. I checked the timing and it is on about 27 degrees. Anymore suggestions for me?<br />Thanks:<br />Jason<br />BTW: You mentioned something about being overcarbed, you don't think the 115 carbs will be too small for that motor do you? I have noticed that my plugs are always real black and oily all the time. It has the 135 jet sizes in it right now. What do you think I should do?

 

[Dhadley]

Re: Dhadley........Talk to me!!!!!!

Very good. Your rig responded well to the increased X dimension. Yes you could go higher since the prop is not cavitating now. If you are in the top hole now, you may want to consider a jackplate. Even a manual one.<br /><br />What kind of a boat is it? What prop are you using?

 

[4link1955]

Re: Dhadley........Talk to me!!!!!!

The boat is a 1985 18' Sunbird. The boat does have a pad under it also. The prop I'm running is a OMC 13-1/4"x19 S.S. prop. What do you think about the oily plugs and the 115 carbs?<br />Thanks:<br />Jason

 

[Dhadley]

Re: Dhadley........Talk to me!!!!!!

Here's how we test for rich/lean running -- run far enough at speed to make sure the motors running as best it can. Usually a 1/4 mile is enough. Push in the key to activate the primer. If the motor loses rpm and "blubbers" instantly, its running rich. If you pick up rpms for a split second, then you lose rpms and it "blubbers", its running lean.<br /><br />When it's jetted correctly you can activate the primer - nothing will change for the first split second and then rpms will fall off as its flooded.<br /><br />You can do it this way on your motor if you remove the choke butterflies and install the primer system. Pretty easy to do. You may have done it already.<br /><br />As for the carbs, I would just try them one day. At least it will give you a reference point.<br /><br />Good luck!

 

[4link1955]

Re: Dhadley........Talk to me!!!!!!

Dhadley,<br />What kind of primer system are you talking about? I've never heard of it. Is an aftermarket unit or is it homemade? I'm still running the choke butterflies.<br />Thanks:<br />Jason

 

[DJ]

Re: Dhadley........Talk to me!!!!!!

Jason,<br /><br />The primer system replaced chokes on OMC engines sometime in the late seventies, early eighties.<br /><br />It squirts fuel into the carb thoats as opposed to blocking off the air flow.<br /><br />It's an easy conversion.

 

[4link1955]

Re: Dhadley........Talk to me!!!!!!

djohns19,<br />Where can you get this primer system from? Any ideas. I like the sound of it alot.<br />Thanks:<br />Jason