Electrical gremlin???

timoNZ

timoNZ

less work more surf
Location
Gisborne New Zealand
Hey guys after some ideas on what to look at next!

Details : fitted a newly built HPE820 5mm long rod stroker.
185psi compression
Protect adjustable rev limit CDI
B pipe
OEM 44mm carbs
62T electricals

Have battled with a miss from day one, I have got the miss a lot better but it is still playing up.
Current symptom is the ski runs perfectly for 15-20 minutes then under load it develops a slight miss similar to the rev limiter but less aggressive at around 1/2 throttle. Ski is still rideable just not 100%. Only happens in the surf (salt water) its fine in the lake. I don't think its carb setup as it is flawless when in fresh water or for the first 15-20 minutes. No hesitation or loading up in the no wake zone.

Things I have tried:
Replaced with known to be good one part at a time then test
Stator
CDI
Coil
Flywheel
Start stop switch

Other things I have tried
Have fully rewired everything
Changed the exhaust gasket (thinking it may have had a pin hole leak that opened up as the motor fully warmed up)
Different jetting /pop off setting to check it wasn't carb set up
Replacing the plug caps and cutting back the leads
Checked all the resistances and voltages of coils all test fine.


On the last ride my buddy suggested we reduce the plug gap when the miss developed. This eliminated the miss. So from this its clear that the spark is weak but isn't fixed by replacing any of the electrical parts. Could the issue be that the 62T ignition may not have the grunt to fire the higher compression motor. Do I replace the CDI with an MSD enhancer? Why would this only be an issue after 15-20m in the surf ?

Also is there any difference between a 650 coil and a 701coil besides part number??

Any suggestions would be welcome.
My next action may be gallon of gas and some matches at this point
 
ryan0

ryan0

Location
kent island maryland
I had a similar issue once before with one of my first skis. I swore it was the enhancer or coil so I replaced them both it seemed to go away for about a month but started to come back. Frustrated I figured it never hurts to add grounds so I ended up making a ground cable to go from the ground bolt on the starter to the ear of my e box then another ground from that same ebox ear to the battery it made a night and day difference in how the ski ran. I was so surprised so I popped back in my old electronics that I thought were bad and both work perfectly and iv been running them for 4 years with zero issues.

One note make sure to sand down the ebox ear to bare metal to make a clean connection and use some dielectric grease so it won't corrode.


Sent from my iPhone using Tapatalk
 
High Speed Industries

High Speed Industries

Your one stop shop for quality parts @highspeedind
Location
Lake Havasu City, AZ
timoNZ said:
Hey guys after some ideas on what to look at next!

Details : fitted a newly built HPE820 5mm long rod stroker.
185psi compression
Protect adjustable rev limit CDI
B pipe
OEM 44mm carbs
62T electricals

Have battled with a miss from day one, I have got the miss a lot better but it is still playing up.
Current symptom is the ski runs perfectly for 15-20 minutes then under load it develops a slight miss similar to the rev limiter but less aggressive at around 1/2 throttle. Ski is still rideable just not 100%. Only happens in the surf (salt water) its fine in the lake. I don't think its carb setup as it is flawless when in fresh water or for the first 15-20 minutes. No hesitation or loading up in the no wake zone.

Things I have tried:
Replaced with known to be good one part at a time then test
Stator
CDI
Coil
Flywheel
Start stop switch

Other things I have tried
Have fully rewired everything
Changed the exhaust gasket (thinking it may have had a pin hole leak that opened up as the motor fully warmed up)
Different jetting /pop off setting to check it wasn't carb set up
Replacing the plug caps and cutting back the leads
Checked all the resistances and voltages of coils all test fine.


On the last ride my buddy suggested we reduce the plug gap when the miss developed. This eliminated the miss. So from this its clear that the spark is weak but isn't fixed by replacing any of the electrical parts. Could the issue be that the 62T ignition may not have the grunt to fire the higher compression motor. Do I replace the CDI with an MSD enhancer? Why would this only be an issue after 15-20m in the surf ?

Also is there any difference between a 650 coil and a 701coil besides part number??

Any suggestions would be welcome.
My next action may be gallon of gas and some matches at this point
Click to expand...

Judging by your location I would contact Roger Parker with Liquid Fix Watercraft. He's somewhat close to you and he will have everything you need to get your ski working again. Roger is based out of Auckand, NZ. Pm me if you need his contact info.
 
V

Vortex

Location
Southeast
Definitely get the enhancer and only use new OEM coils. Also check your battery cables and contacts on both sides for corrosion.

Make sure the plug wires are wrapped with extra insulation and isolated from each other so they never touch.

Salt water does weird stuff when it gets in the hull, I have had a similar set of problems where the ski runs good in fresh water but not salt, I think water intrusion on to a billet head can cause weird stuff to happen
 
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