Compression # on my 87' Evinrude XP 200...could I have a problem

[edwinbonneau]

Decarbed this afternoon and here are my current "warm" compression # on my 87' Evinrude XP 200

1- 95
2- 100
3- 90
4- 85
5- 90
6- 85

Manual states that there should not be a variation of more than 15psi....I am within those limits but wanted a second opinion.

I've been having problems with the motor after it gets warm. It doesn't like to transition between idle and WOT. It's usually a pretty slow transition or the engine dies. I believe this to be only when the engine is warm. Any input would be greatly appreciated.

 

[daselbee]

Re: Compression # on my 87' Evinrude XP 200...could I have a problem

I realize what the manual says about cyl comp. variation, but I honestly think you will be fine for quite some time. I like to see them higher that 85...I like them in the 100-110 range, but this is strictly my opinion. Your bogging is likely due to link and sync issues. Check the throttle cam pickup roller (cracked outer sheath) and smooth movement of the timer base as you advance the throttle.
Check for good strong spark jump on all six of at least 7/16".
You basically want the spark advance to start just ahead of the throttle opening.
Of course there are many other things that will cause bogging, but this inspection is absolutly free.

 

[boobie]

Re: Compression # on my 87' Evinrude XP 200...could I have a problem

Your compression #'s look okay. I'd look for something else as suggested above. Make sure your timer base moves freely.

 

[edwinbonneau]

Re: Compression # on my 87' Evinrude XP 200...could I have a problem

++My tach doesnt work, nor does my system charge my battery. (i get by because of my on board charger, charges all batteries when im parked at the house), could the stator or rectifier be causing my bogging problems++

Well your opinion is shared in the manual. They say over 100 but that the range is far more important (for obvious reasons). I am a noob at this but I assume that as rings and cylinder walls wear the compression lowers naturally due to that wear. I just want to make sure before I go trying to troubleshoot this bogging down that it isn't because of a bad cylinder.

I generally like to work smarter than harder but usually that doesn't happen. Hopefully with this forum I can work a little smarter. Any input on nailing down this issue would be appreciated. Thanks bee

 

[boobie]

Re: Compression # on my 87' Evinrude XP 200...could I have a problem

The tach works off of the charging system. Charging system won't cause your bogging down probs. As far as the charging system it could be stator or voltage reg.

 

[edwinbonneau]

Re: Compression # on my 87' Evinrude XP 200...could I have a problem

Good news! after much frustration and troubleshooting...rebuilding all the carbs, decarbing, replacing fuel lines...the list goes on and on I finally found "the" problem. While replacing fuel lines I pulled the main pickup line out of the tank.....there is a screen on the end of that line. After putting everything back together and getting back out on the water I still was having problems...then it struck me about the screen....I had previously drained the tank of perfectly good fuel to make sure it wasn't a fuel issue and noted that the fuel looked great, no discoloration or sediment. The screen "filtered" all the fuel as I siphoned it out. There was in fact sediment in the tank. I ended up taking out the screen and adding an inexpensive fuel filter which is clearly filtering out all that sediment without completely clogging my fuel line.

Any ideas on removing sediment from the tank? My current plan is to flush the filter every so often. Eventually I will filter out all that sediment.

Engine ran great today...such a relief to find a solution!

 

[edwinbonneau]

Re: Compression # on my 87' Evinrude XP 200...could I have a problem

Can't wait to post pictures of what is being filtered out of my tank...it's scary. I think I'm going to a get it "flushed" by someone with the right tools. I drained all the fuel but I know im missing all kinds of crap down there...any suggestions other than taking it somewhere to have them filter the fuel?