Power trim causes power loss on OMC Cobra...?

[Stan's Customs]

Re: Power trim causes power loss on OMC Cobra...?

WEll... <br /> the distributor part came in and after the rain let up I was able to put the boat on the lake. The wrongly positioned ignitor plate was most of the problem. The engine goes to 4600 easily with me only in the boat. It would probably go higher trimmed out further, but that's about it for the cam, judging from the increase in rpm without increase in power. I figure that a loaded boat will keep me at max rpm @ wot and full trim. I really thought this boat would be way under proped with this 17, but it seems good. It's a Four Winns 200 with a 5.7 Cobra. Most of my similar boats in the past used a 19 to ski..sometimes a 21, never a 17.<br /><br />Now back to the other problem...When the trim is "bumped" the motor cuts out a little. But when the trim is firmly held in it does "not" cut out??<br /><br />I generally just bump the trim till it sounds good, so this is really awkward. When you nail the switch it doesn't cut out just goes to far. When you just bump it it cuts out a little and you can't tell if it sounds just right ..if you get my meaning. (right before cavitation).<br /><br />Seems like it would be worse the longer you hold the trim button in ...but no. Does that still act like the trim motor is pulling too many amps or some similar problem? Could it be the control handle switch someway?<br /><br /><br />Thanks ...Stan

 

[Stan's Customs]

Re: Power trim causes power loss on OMC Cobra...?

Sorry about the Multiple post...???<br /><br />Ok Tom..<br /><br />I left my test meter at the shop when I went to the lake to see if the other prob was fixed...not that it would have mattered, I was by myself anyway.<br /><br />We've been plaiged with constant rain for the better part of ten days and then the threat of cold whether. So I was decided to winterize the boat before the front came in. It'll be spring before it goes out again, in fact I may change the engine now that I've tried the boat out. (runs good but has a lot of blow by) I wasn't even sure I would keep it before I tested it running half way right.I wanted to see how it would come out, and handle choppy water etc.<br /><br />The glich is so quick I figure it will be hard to read on a meter..so I was just fishing for ideas. Thought someone might have had the same thing happen. If it were a constant miss it would register I'm sure. It only does it when you try to bump the trim quickly. It doesn't act like an amperage overload to me...acts like its just loosing fire briefly or something. The trim motor sounds good too...for what it's worth.<br /><br />Thanks ...Stan

 

[tommays]

Re: Power trim causes power loss on OMC Cobra...?

stan<br />most DVM should be fast enough to pick it up if you have some leads with clips you should be able to hook up under your dash if you need to<br /><br />a lot of meters have a min and max that will stay in memory its pretty slick the features they keep adding <br /><br />after your starter the trim pump is the bigest amp draw on many boats<br /><br />tommays

 

[Stan's Customs]

Re: Power trim causes power loss on OMC Cobra...?

You are right Tom...the new test equipment is pretty cool. I guess it's time I upgraded, I've had my volt/amp meter 15 or 20 years probably.<br /><br />I'm sure there is a draw on the battery when the trim is activated. Just like there is a draw on a car battery when lights are turned on...or an off road or work vehicle with a power inverter (they draw a lot of juice). The engines don't missfire when you have a current draw on those. <br /><br />Let's assume that it is a given that the battery will spike and I can catch it on a new meter ..then what? I'm not sure why it would affect a boat system differently than a voltage draw on an automobile. What am I looking for precisely... I'm confused. <br /><br />Don't forget that trim does not cause a missfire when firmly engaged, only when bumped.<br /><br />Stan

 

[tommays]

Re: Power trim causes power loss on OMC Cobra...?

stan<br />most motors will draw 3 times there running current on spin up and drop down when they reach speed which is why your ok on longer trims<br /><br />i think once your sure what the real cause is you can decide to live with it or keep and eye if it gets worse and repiar or replace if it becomes a biger problem<br /><br />tommays

 

[Stan's Customs]

Re: Power trim causes power loss on OMC Cobra...?

OK..Tom<br /><br />10-4 on the voltage spike on start of any electric motor. <br /><br />So..the cure is to replace the trim motor? It's not something I can live with....I don't think anyone else would either, it keeps you from fine tuning your trim easily.<br /><br />A new motor will spike too, I guess not as much....<br /><br /> I wonder why this doesn't manifest itself in the automotive field, there are lots of high amp draw accessories out there..big electric winches and so on. I'm not aware of that ever happening under those applications...it just doesn't make sense to me. Must have much lighter wiring or something...I'm still puzzled. But you guys have traveled this road and I bow to the boat pros experience. If that's usually the problem it most likely is the problem on this rig as well...<br /><br />Thanks again for all the help...<br /><br />Stan

 

[tommays]

Re: Power trim causes power loss on OMC Cobra...?

Stan<br />its and expensive part which is why i am recomending that you test everthing carefully first theres still the possabilty of a bad connection or a problem on your boat that even a new motor would still cause the problem<br /><br />the motor can usally have only the brushes changed in many cases if it will still come apart<br /><br />tommays