02 XR6 150HP HESITATION

[VANDERA]

I have a 2002 XR6 150 #0t589517. It idles well, but when I go to get on plane it sounds like it is missing pretty bad (maybe around 3000rpms). Then once I'm on plane it smooths out and hits top end just like it should. My guesses would be a coil acting up or possibly a carb jet plugged. Has anyone else had this same problem? Is there a way to test a coil that only acts up under load? It started a month ago when I had it out. I changed the plugs (which didn't look bad) and it is still acting up. Also it got a new fuel line and primer bulb a year ago when I bought it.

[EuropeanAM]

What plugs/gap did you use?

Did you change the Fuel Filter?

Checked Sync-n-Link settings?

When diagnosing a performance problem, it is ALWAYS best to start with the BASICS:

-Compression Test
-Spark Test
-Fuel Quality/Delivery Tests
-Reed Inspection

[VANDERA]

What plugs/gap did you use?

Did you change the Fuel Filter?

Checked Sync-n-Link settings?

When diagnosing a performance problem, it is ALWAYS best to start with the BASICS:

-Compression Test
-Spark Test
-Fuel Quality/Delivery Tests
-Reed Inspection

Champion QL77JC4 .040" gap

Did not change fuel filter.

I've done automotive work but I'm not familiar with Sync-n-Link or with reeds.

I'll try to do a compression, and spark test this weekend. and check the fuel filter

Do you know if those coils can just act up under heavy load?

[EuropeanAM]

Try a set of the CORRECT spark plugs FIRST: NGK: BPZ8HS-10 (.040" gap).

[VANDERA]

So its been a awhile since I posted. Last fall I changed the fuel filter and did a compression test. I don't remember exact numbers but all cylinders were within about 6 lbs of each other. I also sprayed some carb cleaner through carbs while it idled on the hose. I let it run for about five minutes to run through a heavy dose of quickleen and quickstore before it sat in the garage for a few months. I changed the plugs to the correctly gaped NGKs stated above. I took the boat out sunday for the first time and ran it. I added 5 gallons of fresh gas on top of the 5 or 6 gallons that was in the tank and added another 1 1/2oz of kwickleen. It was only 45 degrees out and it started very hard. Another issue it has had since i bought it a year and a half ago is that the starter kicks out after about a second or two of cranking, which makes it even harder to start. It spins but the drive gear disengages from the flywheel. What would cause that? I have a 27 series battery with 575cca. It is less than a year old and tests good. I finally got it started and it idled rough and I could tell it was missing. It missed bad while getting on pad but seemed to smooth out above maybe 3000rpms. I noticed the tack was jumping around at idle also, which it never did last year. I haven't had time to look at it since I had it out. I know I need to do a spark test. Can I just hook an in line tester between the plug and the wire or is there a better way of checking spark? What else should I be doing? Things to check?

[EuropeanAM]

Carb cleaner isn't really a good idea, as it seldom contains the necessary LUBRICANT for the engine. It's also not really reaching the areas that need to be cleaned if there really is a problem in the carbs (complete disassembly is required).

Spark test is next on your agenda. A spark board tester is best, if you don't have one, you can try a timing light (clip inductive pickup lead to each plug wire, one at a time, while watching for a steady-flashing pattern).

If you have good compression, good spark, and good plugs, the problem is almost certainly fuel delivery (or reeds).

Tach: May be the adjustment pot-switch on the back of the tach is corroded internally. Note current position, move a couple positions back and forth, then return to the original position and see how it does.

[VANDERA]

Thanks Don. I did a spark test with a timing light. It jumped around between 720 to 750 and periodically spiked to about 800 for a split second and dropped to about 680 for a split second. Is that normal?

[VANDERA]

It was pretty close to the same on every cylinder

[RWHorton]

Electrical issues rarely get better as the engine speed increases, This sound much like a fuel delivery issue. Sounds like the float is not right or there is gas bleeding by the seat which will cause a rich issue and as the engine speed increases the engine start to see the right gas/fuel ratio. Just a guess though.

[EuropeanAM]

Pay attention to the "flashing pattern" of the timing light (not nearly as interested in the RPM figures at this moment). Flashing pattern should be strong and consistent.

You mentioned that you installed the correct/gapped NGK plugs. Please confirm for certainty that you used ONLY this exact spark plug: BPZ8HS-10