View Full Version : '87 Prostar 190 questions.

08-02-2004, 10:58 PM
Hello all, new to the site.. Great site by the way!

I have a 1987 PS190 w/ the 351..

I have a few questions.. What temps should I be seeing @ idle, @ speed, etc.?

What should the points be gapped too.? where should the timing be set.?


Dan K
08-03-2004, 08:57 AM
Welcome to the site !
In answer to your questions;
The temp should be around 140 when running, it will rise slightly once you shut it down. These motors geerally run cool since you are constantly supplying them with cool water.

In regards to your other questions, I highly recommend you change over to electronic ignition. It can be done for around $100 and is as easy to do as changing the points. I did mine earlier this year and like others will tell you, it is the single biggest improvement you can make and will never be sorry about it. You can search this site for recommended sources, I used Vince at SkiDim and was satisfied with the price and service.

east tx skier
08-03-2004, 10:42 AM
Once I warm up, my temp sits on 160 (with the slight rise due to heat soak when shut down).

08-03-2004, 07:16 PM
So my boat is runnin' on the hot side.. Probably due for an impeller..

So after removing the housing I noticed the impeller doesn't look in too bad of shape but a couple of the blades (for lack of a better term) are cracked. I'm assuming this is NO good. So how do I go about removing the impeller from the housing..?

08-04-2004, 12:44 AM
You can use two screw drivers to pry it out or buy a special tool (called an impeller puller :) ) from West Marine for about $60. There is a thread on the old site that gives step by step instructions so try a search there. I don't know if they are available on the new site yet. Tips that I've read about are to lube the impeller up with dish soap, pull the netural safety switch off, crank the engine for a couple of seconds and the impeller will work its way out some and then grab it with plyers. As for me, I purchased the impeller puller which is a nice tool for a vdrive as access is limited. Here is a link to the impeller puller and you can probably find it elsewhere and cheaper.

Impeller Puller (http://www.westmarine.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&langId=-1&catalogId=10001&productId=25413)

08-04-2004, 08:42 AM
My '88 runs at 160. The manual says that normal operating temp is 140 to 180. I am running a 142 thermostat the 160 thermostat made it run a bit hot .

As for the points go with the advise given and throw them away and buy a $99 electronic conversion and never deal with points or starting issues again.

Timing is 10 degrees.

I have had great luck with lubing the impeller up a bit and then cranking it over a few times. Works it loose and then pop it out easily with two screw drivers. No need to spend $60 on a puller since access is so easy.

08-04-2004, 10:47 AM
I have an '87 Tristar with a 351. It runs at about 160 degrees.
I disagree with the 10 degree timing, though. Mine is set at 6. Jimn?

08-04-2004, 11:08 AM
My 87' 190 runs @ 160 degrees. I just set my points, but will have to get you that info from the toolbox at home.

08-04-2004, 11:15 AM
The manual says 10 for the 190 Prostar.

08-04-2004, 11:18 AM
Are you sure it isn't 10 degrees for the Chevy 350, but 6 for the Ford 351? I'm pretty sure it's 6.

08-08-2004, 08:54 PM
After an impeller change the temps are normal (130-160) I suppose but I'm still seing high / higher (190*) temps at speed, is this normal.?

These points are going to be the death of me.. where is a good place to order the conversion kit from.? any dist. in Canada.?

So do I got w/ 6* or 10* any confirmation on this one.?


08-08-2004, 09:08 PM
My 87 190, 160 normal, 180 after a hard slalom pass and you shut the engine off. 10 degrees TDC. Get rid of the points and get breakerless ignition. It makes the engine run so much better. Only $100 and I posted a photo step-by-step on the other MC site how to do it.

08-08-2004, 09:12 PM

Ski DIM best place in town! Make sure you know whether you have a distributor cap w/clips or the screwdown. Typically screwdown is 87 and up and clips are 86 and lower. However my 87 had clips. It makes a difference in the rotor height. It's very easy to do and I posted some photos. Here it is:


08-08-2004, 10:13 PM
The timing at 6 or 10 degrees BTDC is almost a moot point. 6 with old advance springs will probably get the same maximum advance as 10 with new ones. 10 degrees base timing won't hurt anything unless you're in a really hot, dry area and you're running it hard with low octane or old gas. If you have these conditions, go with 6 and increase the octane a bit to minimized detonation under hard load.

If you plan to change to electronic ignition, change the advance springs and make sure the weights move freely. This is the perfect time to do this since the plate will be accessible or removed, anyway.

08-08-2004, 10:40 PM
Thanks for the quick replies..!

Great step by step BriEOD..!

After you changed over did you bypass the ballast resistor.? Do I need to upgrade the coil from the current 9v coil to 12v coil.?

Thanks again guys..! This site is great.!

08-08-2004, 10:45 PM
I didn't by pass anything and I already had a 12V coil.

08-09-2004, 12:03 AM
i have the original owners manual for our 86 prostar, indmar book says the 351 should be 6 deg at 600 rpms for timing. Plug gap at .35.......and our temp runs consistant 175 with up to 200 occasional. have had no problems with overheating. hope this helps......

08-09-2004, 10:42 AM
If you plan to change to electronic ignition, change the advance springs and make sure the weights move freely. This is the perfect time to do this since the plate will be accessible or removed, anyway.

Where would you find these? skidim doesn't have them listed on their site.

08-09-2004, 05:48 PM
Try NAPA. They, and a lot of other auto parts stores have marine catalogs, they just don't say much about it.

08-09-2004, 07:53 PM
I have a 1990 TRISTAR 190 with the FORD INDMAR 351 and it states timimgn to be 6deg btdc. ALso I am running 120 - 130 deg F. Very cool.

08-09-2004, 09:39 PM
You might want to look at the thermostat and gasket if you're running at 120-130 degrees. That sounds like there may be a chunk of something in the thermostat keeping it from closing. If you remember running in the 140-160 range, you also used less gas then and probably had a bit more power. A motor at 120-130 isn't as efficient as one at 140-160 since the in-cylinder temperatures don't promote full combustion.

08-09-2004, 10:25 PM
Not sure what gives w/ my boat..? I've changed the impeller.. checked the lines all the way from the inlet to the impeller for blockage, nothing. It runs around 140* at idle.. 20mph and below no problems (160-170*), but at 30mph+ climbs to 200*.. :eek3:

Thanks again for the links Brian, I got my conversion kit on order..

08-10-2004, 07:18 AM
Good deal man. You won't be disappointed. It takes about 30 min to an hour to put on.

08-10-2004, 10:31 AM
I'm looking forward to it..! I've heard nothing about good things from people who have switched.. What sort of improvements have you seen since the conversion.?

08-10-2004, 12:33 PM
Make sure you have a good coil and don't ever leave the key in the 'ON' position unless the motor is running. It'll burn out the electronic unit. Ask me how I know this.

I noticed that it starts right away, and I mean, right away. It's like the first cylinder hits and away it goes. I haven't noticed any other real significant improvements, but I think the boat does run better overall. I've heard others mention they picked up a few hundred rpms or noticed a better hole shot.

08-10-2004, 01:37 PM
Mine starts better/easier as well. I haven't noticed major performance when running, but I did pick up some RPM's. Overall it's better, and you don't have to deal with them dam points or condensation, you know the drill.

08-10-2004, 04:35 PM
I'm still a little confused on what coil to go w/.. Since I replaced my coil last season, I think I will just leave it (it's a 9v coil.). The way the system works now is; when the key is "on" and not running (ie "buzzing") there is 12v at the coil for starting; or in other words the ballast reistor is by-passed for starting. Once the engine is running the coil only gets 7-9v through the current limiting Ballast resitor.

So in order to get effcient output from a 12v coil I would need to eliminate the ballast resitor correct.?

08-11-2004, 11:58 AM
This is how it was esplained to me, but I'm not very smart and easily confused, so...

When it's buzzing (key on, motor not running), you're loading up the electronic unit enroute to the coil. That's bad, according to Petronix. He said that is the #1 reason these units fail. He said the #2 reason was having a faulty coil. He said to test the resistance and it shouldn't be less than 1.5 ohms. I don't think he made any statements regarding the voltage, but I could be wrong.

08-12-2004, 09:17 AM
Got the kit from skidim yesterday and installed it.. no probs.. great kit, great instructions, thanks for the reco. BriEOD.!

BUT - In hopes this would cure my starting issues it did not.. but none the less I'm glad I upgraded.!

So here's what I've changed - Plugs, Wires, Coil, cap & rotor, electronic ingnition upgrade, new battery cables, I also replaced the advance springs and set the timing, the starter has one season, the carb / intake have only one season on them aswell.. The compression is w/in 1 or 2lbs between all cyl's..

The only electrically connections I have yet to change are the ones @ the ignition switch.

The problem.. weak spark while cranking; only 5-6.5v on the coil during crank. Jump the coil to battery and presto fires right up..

Where oh where could my problem be..??

PS - Runs like a swiss watch once it's running.

08-12-2004, 09:24 AM
I'm no expert, but isn't the starter relay about the only possibility left?

08-12-2004, 10:09 AM
Sledneck- check the ignition switch for corroded or loose terminals and screws, but don't forget that the 12V to the dash and ignition system goes through the safety switch from the ignition switch. If the lanyard isn't pushing on the safety sw enough, you will have some issues.

08-12-2004, 06:35 PM
I love you JimN...!!!! :worthy: (uhhhh, in a manly way of course..LOL)

The teather switch was actually broken at the back making for a crappy connection.. ordered one in, jumped the wires for now, good as new..!!

Woooooooohoooooooooooooooooooo!!! bring on the week-end..!

08-16-2004, 10:26 AM
Update: This weekend, I moved the timing back from 10 to 6 and noticed a significant improvement in the hole shot and mid-range power.