Where to get a test wheel/prop for OMC

[kimswang]

Where can one get a test wheel for a OMC V8? I am having great difficulties pinpointing the reasons why my RH engine will not go more than 4500RPM. I have replaced one powerpack that gave no spark to #5 Cylinder, compression is good on all 8, no erratic firing (at least not while at lower RPM), idles great, starts easy, runs smooth as silk until WOT, then just boogs down and tach is jumping +/- 500 RPM. The other engines are just pulling it so it runs this fast. By itself it will not even top 3000RPM, while the other two will go 3700RPM by themself. The engine is a 1987 with a 4.0 powerhead and the big bore carbs / 1987 ignition setup. The manual calls for using test wheel to set timing as well as checking for erratic firing at higher RPM. Could it be a timer base gone bad? Any ideas?

[Instigator]

Where can one get a test wheel for a OMC V8? I am having great difficulties pinpointing the reasons why my RH engine will not go more than 4500RPM. I have replaced one powerpack that gave no spark to #5 Cylinder, compression is good on all 8, no erratic firing (at least not while at lower RPM), idles great, starts easy, runs smooth as silk until WOT, then just boogs down and tach is jumping +/- 500 RPM. The other engines are just pulling it so it runs this fast. By itself it will not even top 3000RPM, while the other two will go 3700RPM by themself. The engine is a 1987 with a 4.0 powerhead and the big bore carbs / 1987 ignition setup. The manual calls for using test wheel to set timing as well as checking for erratic firing at higher RPM. Could it be a timer base gone bad? Any ideas?

shift interupter.

If that doesn't work, go to the ramp and start swapping ign parts from one of the good motors until you isolate it.

My old twim powered Sonic had the same problem yrs ago. I bought the test meters and tried tracking it down per the manual and that method indicated a bad stator based on the meter readings.
I tried to order one from Stoker and he wouldn't sell it to me based on the meter readings only.

Didn't trust it.

He told me to do the part swap thing.

I did that and I think it ended up being a power pack! ($300. worth of test equip!)

If you get the pt. # for the test wheel from your manual, they are on e-bay all the time although it may take a while.
I'm sure you can also get them from BRP but not sure of cost??

Hope this helps.

Gary

[lokinutz]

This sounds like complete white trash, but I took a junk aluminum 19 pitch prop and cut half of each blade off with a cut off wheel. I have used it on my v-6 many times, and a buddy just used it on his v-8 without problem. I don't suggest running the thing at 5k for half an hour like this, but it works for 10-15secs at a time to check timing, water pressure, or what ever. Puts enough load on the motor, but doesn't try to push your boat through your tailgate.

[Riverman]

To do the timing on my V4 (different animal but same idea) I used the prop off my 60 Jonny, 11 X 17. All you need is a load so it won't overrev, and not much thrust. Find a POS aluminum prop and trim the blades, that should work fine.

[kimswang]

shift interupter.

If that doesn't work, go to the ramp and start swapping ign parts from one of the good motors until you isolate it.

My old twim powered Sonic had the same problem yrs ago. I bought the test meters and tried tracking it down per the manual and that method indicated a bad stator based on the meter readings.
I tried to order one from Stoker and he wouldn't sell it to me based on the meter readings only.

Didn't trust it.

He told me to do the part swap thing.

I did that and I think it ended up being a power pack! ($300. worth of test equip!)

If you get the pt. # for the test wheel from your manual, they are on e-bay all the time although it may take a while.
I'm sure you can also get them from BRP but not sure of cost??

Hope this helps.

Gary

I checked the interupter, not the case as all plugs are firing. will however, start swapping parts over from my leftie.

[kimswang]

This sounds like complete white trash, but I took a junk aluminum 19 pitch prop and cut half of each blade off with a cut off wheel. I have used it on my v-6 many times, and a buddy just used it on his v-8 without problem. I don't suggest running the thing at 5k for half an hour like this, but it works for 10-15secs at a time to check timing, water pressure, or what ever. Puts enough load on the motor, but doesn't try to push your boat through your tailgate.


Funny, but brilliant. I will make one of those myself and start testing. Thanks..

[Markus]

Funny, but brilliant. I will make one of those myself and start testing. Thanks..

That's what we did too. Some old Mercury service manual showed how to make a test wheel by cutting down the blades of a standard aluminum propeller. I think someone here at S&F sent it to me.

We went to a local prop shop, bought an old aluminum propeller off the shelf and had them cut it for us.