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OK 1996 225EFI Mercury. This weekend motor was acting really weird. Every once in a while it will not plane out. I push the pedal and rpm's will not raise and plane out just plows like it's not getting fuel. I bought a fuel PSI kit. What is the proper procedure for checking the PSI? I connected the PSI tester to motor and turned the key on and it showed 42-44 PSI. Should I check the PSI while running the motor on the water and at WOT? Any suggestions on problem is appreciated.
You also need to verify the fuel pressure while attempting to accelerate. Should remain in the 34-36 psi range at ALL times.
Would also be wise to look at the OTHER basics: Compression test, SPARK TEST (including verifying QL77CC Spark Plugs in good condition), and FUEL DELIVERY.
On the subject of fuel delivery, see this IMPORTANT topic:
http://www.bbcboards.net/zerot...first
You replaces my fuel lines when I was there. http://www.bassboatcentral.com/smileys/Laugh.gif My boat has the wrap with flames you worked on. Anyways Something is going on that I can't figure out with it. Going to try it again tonight to see if it is running any better.
OK I think I found my problem with this issue. If you remember we changed a fuel line on this motor when I was there last month. It goes into the bottom of electric fuel pump. Didn't have any 5/8 hose so we used 3/8 hose instead. I removed the 3/8 and replaced the old 5/8 and now it is planing and smoking just like it did before. However it smokes more when trimmed down than it does when trimmed up. Does this make since. I can raise the motor and it all but stops smoking. Lower it down and it will smoke really bad.
You're probably going to note more smoke when trimmed down, based on the jackplate and trim problems you have (very substantial amount of negative trim angle). Have you taken care of either of these problems yet? http://www.bassboatcentral.com/smileys/praying.gif
Higher trim angles help to decrease backpressure (and bring the idle relief hole higher up out of the water).
If you'd like to order that u-hose, Rhonda would be glad to order one for you (as you recall, it's not something we kept in stock).
In the meantime, let's keep the old one in place. http://www.bassboatcentral.com/smileys/wink.gif
I got a 10'' jackplate and got a new trim. So that problem has been fixed. Now I can't figure out the remaining problems.
I'd recommend you get the replacement hose on order.... and install it FIRST.
Drop me an email- I may have another item for you to look at (and you may already have the part). http://www.bassboatcentral.com/smileys/wink.gif
And followup reply. Let me know if you have any further questions. http://www.bassboatcentral.com/smileys/thumbsup2.gif
Thanks Don that will be done in the morning. I have both pressure valves. Thanks going to try and run motor tomorrow and see how it is doing. Also my tach is not working properly any suggestions?
If the tach is moving AT ALL.... check the back of the tach. There may be an "adjustment pot switch" there.
Utilizing a small, flatblade screwdriver, move the adjuster ONE OR TWO positions (don't rotate it further than two positions). Return the adjuster to the original setting, and see how it does.
The tach is moving. At idle it shows the correct rpm. However at WOT the most it will show is 5000rpm. I installed a 27 tempest plus. It showed 5000rpm. Installed a 24 tempest plus it showed 5000rpm. I installed a 26 4 blade yamaha prop it showed 5000rpm. I will try and adjust on the tach. It does have an adjustment pot switch. Thanks Don.
That tach may actually be bad (needle hanging at 5000 RPM's). Easy enough to confirm- all you need is an "inductive pickup tachometer" (attached to the #1 spark plug wire).
Many "higher end" timing lights are equipped with this feature.