2000 200hp ficht rpm jumps

[fireman_bob]

Boat has run fine since launch this year. Today after running in from a storm I noticed that rpms suddenly jump from 2600 to 3000 with no change in throttle position. The issue is very repeatable, where I can slowly move the throttle up to around 2500 with no problems, then right as it hits 2600, the motor surges and the rpms go up to just over 3000. There don't seem to be any other issues with the idle or running that I notice. Back at my slip can rev in neutral with no jump. Spun prop, TPS, any ideas?

 

[fireman_bob]

Re: 2000 200hp ficht rpm jumps

Update: I put my spare prop on to rule out a spun prop and I took the boat out for a ride and found that the motor no longer jumps rpm at 2600, but I'm not able to get up on plane. The motor never gets to high enough RPM and doesn't feel like it has enough power. I had a similar issue last year and it turned out to be a bad coil. I checked resistance on all 6 coils and they were good, but I'm going to check spark tomorrow with a timing light.
Any other ideas?

 

[fireman_bob]

Re: 2000 200hp ficht rpm jumps, loss of power at WOT.

Re: 2000 200hp ficht rpm jumps, loss of power at WOT.

I guess I'm just talking to myself here. For the benefit of anyone that finds this thread with a similar issue, the problem turned out to be a dirty coil connection on the #5 cylinder. I ended up taking all of the coils off, cleaning the connections, ground straps, and block points where the coils mount, then putting everything back together. Now the motor runs great again. I like a cheap fix

 

[boobie]

Re: 2000 200hp ficht rpm jumps, loss of power at WOT.

Re: 2000 200hp ficht rpm jumps, loss of power at WOT.

Your posts were very informative. This is the first time I saw it and it was good info. As I always said "It's the little things that will get you ". Good work !!

 

[fireman_bob]

Re: 2000 200hp ficht rpm jumps, loss of power at WOT.

Re: 2000 200hp ficht rpm jumps, loss of power at WOT.

Thank you. My plan is to recoat the coil mounting screws and straps with liquid electrical tape. By the way, for anyone interested, I was able to restore a "bad" coil that had a broken ground strap that had corroded off the housing by digging out the RTV around where the strap goes into the coil housing. Once in there, you'll see where the coil wires are soldered to the strap on a metal post. For the fix, I soldered a short piece of #12ga wire to the post and put a crimp ring terminal on the other end that contacts the block. The length of the wire and terminal are such that the mounting screw can pass through the terminal hole to make the circuit connection to the block. I only used one wire on the topside of the housing (for each coil) and it seems to work just fine. I used a high quality marine terminal with the heat shrink housing. Make the wire as short as possible. RTV the hole back up and you're good to go.
Seems that these coils are a poor design in that the ground straps are so thin they corrode away, but the coils are still good inside. Once the connection to the ground is restored, the coils are good as new.