Engine Repair - Misfire on a 351W HO? + battery cables

Misfire on a 351W HO? + battery cables

Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=49845
Printed Date: October-05-2024 at 3:23pm

Topic: Misfire on a 351W HO? + battery cables

Posted By: Goldcup101
Subject: Misfire on a 351W HO? + battery cables
Date Posted: May-25-2021 at 7:20am

1997 Ski Nautique with HO Carb engine and QFT carb.

Out for first weekend on the lake and can hear an occasional misfire while running under load. It just sounds like a dull pulse which I assume is a cylinder occasionally not firing. There's no splutter or anything; sounds electrical. Happens at most engine speeds and irregularly but maybe a couple of times per minute. Checked distributor cap, leads and plugs - all good. Since it's happening at speed, it's pretty hard to check with a plug light etc. Idle is a bit irregular anyway (hunts/surges a little) so I'm unsure if this is happening at idle too. Any ideas please?

2nd issue which I presume isn't connected. (But could it be?) Occasionally when turning the key I just get the solenoid click and the engine won't turn. (It's always at the worst possible moment too, isn't it!) The battery connections are a bit suspect since the cables are due replacement so guess this could be to blame? Solenoid and coil were recently replaced so think it's unlikely to be that. Battery is new and it has done this when engine is warm and cold.

If anyone happens to know the battery cable lengths I need for a 1997 Ski, I'd be very grateful as measuring them in situ doesn't seem easy and I want to leave them in place to pull the new ones through. I'm aware that most recommend replacing the cables with 1 AWG.

Thanks all!

Replies:

Posted By: TRBenj
Date Posted: May-25-2021 at 11:37am

If you can spot a bad cap/rotor/plug/wire by visual inspection 100% of the time, that is impressive. At least half the time, bad ones look perfectly fine to my eyes.

Posted By: Jonny Quest
Date Posted: May-25-2021 at 12:34pm

All things electrical come to mind: cap, rotor, coil, wires, plugs and inductive crossfire are potential culprits.

-------------
Current
2003 Ski Nautique 206 Limited

Previous
2001 Ski Nautique Open Bow
1994 Ski Nautique Open Bow

Aqua skiing, ergo sum

Posted By: Goldcup101
Date Posted: May-25-2021 at 1:48pm

I hear you guys. Rotor, cap, coil and solenoid have all been replaced in the last couple of years hence my assumption they're ok but I guess that doesn't mean they can't fail. I've got a new set of leads so I'll start with those and go through the list. None are crazy expensive so shouldn't break the bank. You can educate me about conductive crossfire though! What's that?

Posted By: Jonny Quest
Date Posted: May-25-2021 at 4:12pm

Do a google search for “spark plug wire crossfire” or “inductive crossfire” and you will have plenty of reading material.

-------------
Current
2003 Ski Nautique 206 Limited

Previous
2001 Ski Nautique Open Bow
1994 Ski Nautique Open Bow

Aqua skiing, ergo sum