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500KE30 07-24-2013 12:35 AM

'87 Prostar 190 2500 rev limit?
I recently bought a 1987 Prostar 190. I bought it cheap because it didn't run. After replacing the battery, fuel filters, starter, spark plugs, points, capacitor and rebuilding the carb the boat now starts and idles well. The problem I have is the boat won't rev past 2500 RPM. Whether I move the throttle quickly or slowly I cannot get it to rev past about 2500. Is there a rev limiter on these boats when they are not in gear? So far, I've only started and reved the engine in my driveway while in neutral.

Thanks for your help

half a can 07-24-2013 12:38 AM

Kindof. The throttle lever will hit the knob that you pull out to put it in neutral. This will limit the RPM's. If for some reason you want to rev it higher, push the throttle in the "reverse" direction.

500KE30 07-24-2013 12:45 AM

I intentionally disconnected the throttle lever from the carb. I've been opening the throttle right at the carb. I want to see if the engine will rev (in neutral) before confirming the transmission is ok or not.

catamount 07-24-2013 02:48 PM

Have you confirmed that the timing is right? There is certainly no limiter at 2500 rpm. How strong does the engine sound at 2500? Bad gas?

500KE30 07-24-2013 03:14 PM

Yes, timing was confirmed to be set at 6 degrees. Which is what it is supposed to be according to the owner's manual. The gas is only two weeks old. The engine sounds and runs fine up until 2500. A co worker has an older fishing boat. He said his boat has a rev limit when it's not in gear. I'm taking my boat to the water today to see if it still acts that way in gear or not.

catamount 07-24-2013 03:23 PM

6 sounds pretty late. I haven't seen that spec'd anywhere before. Everything I've read on here says initial timing should be 10 degrees BTDC. I've heard mention of 8 before, but never as late as 6.

How much advance are you getting? If your springs are rusted up and you're only getting marginal advance combined with late initial timing, this could explain your RPM problem.

As mentioned above, the only "limit" on rev in neutral is at the throttle control. If you've disconnected that, there is no limit at the throttle body.

thatsmrmastercraft 07-24-2013 03:32 PM

Timing specs range from 6-10. I am not aware of a rev limiter. Did you set points by dwell or rely on point gap? Have you verified correct firing order?

500KE30 07-24-2013 04:35 PM

Points were adjusted to 0.018 by gap. I do not know what my advance is. I'll have to check that. I am assuming the firing order is ok since it idles smoothly.

etduc 07-24-2013 05:17 PM

Check to see, if you distributor is advancing properly. Also, I'd back your idle timing to 10 btdc, for running on low grade 89 or less octane.

thatsmrmastercraft 07-24-2013 05:21 PM


Originally Posted by 500KE30 (Post 960200)
Points were adjusted to 0.018 by gap. I do not know what my advance is. I'll have to check that. I am assuming the firing order is ok since it idles smoothly.

Never assume the firing order is OK because it idles. I tried that and pulled my hair out for a while. Are you getting any backfiring?

Dwell should be 26-31 and I have .017 for the gap.

After thinking about this for a while, I suspect you aren't getting any advance out of your distributor. Hood up your timing light and bring up the speed and see what happens.

How are you supplying water to your engine for driveway running? You want to be sure not to starve your engine of water. It sucks down a lot once above idle speed much.

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