Cruising RPM Stringer 800

[allen.st]

I have a 1976 Reinell 267 (25') Fly bridge Cruiser with a Ford 351 and a OMC Stringer 800. I need to know the upper RPM limits for this setup. I have been working on this for a year and my last problem is the 2 temp gauges do not even come close. At 3500 RPM the upper one pegs on hot and the lower is at 180, so I am replacing both gauges and sender but I don’t want to tear up the out drive as the motor out of gear will hit 5,000 RMP easily.

 

[Boatist]

Re: Cruising RPM Stringer 800

I guess I do not under stand the question. The Temperature sending unit is in the engine block not the outdrive. If the guage on the fly bridge and the guage at the lower helm station do not match then one guages is bad. Check the engine actual temperature and work on the guage that is wrong. <br /><br />I do not know what this has to do with RPMS.

 

[Dunaruna]

Re: Cruising RPM Stringer 800

Hi sdt, welcome to i-boats!<br /><br />Stock standard 30 year old 351? Don't want too push it much past 4 maybe 4 1/2. Watch the oil pressure. They'll go to 5 but it could get ugly.<br /><br />Don't know what RPM the stringer drive can handle.<br /><br />Aldo

 

[allen.st]

Re: Cruising RPM Stringer 800

Main concern is overall operating RPM, I do not want to tear up the outdive from to much power. When not in gear this engine will turn over 5,000 RPM but is that safe for a OMC 800? With my current temp problem I have not had the RPM over 3500.<br /><br />Thanks

 

[tommays]

Re: Cruising RPM Stringer 800

your real concern should be the drive your moveing a lot of boat with and old drive that is getting hard (or not at all) to get parts for<br /><br /> you should treat it gently and it will last if you push it hard its going to be unhappy <br /><br />with your overheat you need to first check that the raw water pump is working and then check each part for water flow it could be water not getting in as well as water not being able to get out<br /><br />tommays

 

[KaGee]

Re: Cruising RPM Stringer 800

4200-4500 RPM WOT max, in gear, in open water. Any higher than that and you could have a prop issue. Cruise at about 3200-3500. I would'nt rev any engine that high of rpm (5000) out of gear. It's hard on the engine. 180 temps are a little high. What theomostat is in the engine? When was the last time the water pump impellor was replaced? Have the manifolds been checked for water blockage?<br /><br />The 800 Stringer is a stout drive when taken care of. DO NOT operate engine with the drive in any position other than all the way down. DO NOT allow your engine to idle at more than 650-700 RPM and shift. In both cases it is very hard on the ball gears, in the later, it's hard on your clutch dogs and shift cable too. One website I read states that the vast majority of Stringer problems they service were caused by shifting at too high idle RPMs. The motor has an idle problem, so rather than properly fix the problem, the idle screw was adjusted until the motor would idle without stalling. Also, OMC did not use accelerater return springs on the older models. You should add one if you don't have one.<br /><br />As Tommays said, it's a discontinued piece, but parts are available on line from several 3rd party suppliers. Bombardier who bought the assets of OMC still have some parts. They are expensive, but aren't they all??

 

[Don S]

Re: Cruising RPM Stringer 800

If you get new sender and gauges, make sure the sender is for a dual station setup or the gauges will not read correctly. Both gauges should be working off the same wire, so check all the connections also.<br />Regarding the rpm, those engines should get in the 42 to 4400 rpm range at wide open throttle, that doesn't mean you have to run there, it's just an rpm used to show the engine and drive are not being overloaded due to over propping. The rpm in neutral means nothing. That's like putting your foot on the floor in your car while in neutral.

 

[allen.st]

Re: Cruising RPM Stringer 800

Yes Tommays I know it is pushing about 6,500 lbs of hole in the water "LOL" I have rebuilt the water pump and tested it per to 2 shop manuals and pump well over the minimum guidelines.<br /><br />KaGee, this engine does not seem to want to start unless the throttle is set at about 4,000 and it wont idel under 1,000 so I will add a carb rebuild kit to my upcomming order. I have been lucky with parts so far ie I picked up a complete, working Select Trim with motor, Pump, mounts even tubing for $72 "G"<br /><br />Don S I chatted with Teleflex about the sending unit and they said it can be wired with a single wire or 2 wires, but my concern is with one wire and the distance I have to go it might be better to use 2 wires the same length so as both gauges will read the same??

 

[allen.st]

Re: Cruising RPM Stringer 800

Don S the prop will be a new issue once I can get it up to speed to see if it will even plane, I do have the tab working but at 3,200 it is only doing about 6.5 mph per gps. This boat was a basket case when I got it so it may have the wrong prop on it, I have had it rebuilt but it could still be the wrong one.

 

[Don S]

Re: Cruising RPM Stringer 800

I chatted with Teleflex about the sending unit and they said it can be wired with a single wire or 2 wires, but my concern is with one wire and the distance I have to go it might be better to use 2 wires the same length so as both gauges will read the same??

That's not the way to go about curing your problem. All the gauges work on 2 wires basically. The ground is usually through the normal engine wiring harness ground. If you have a bad ground or a bad positive wire for that matter,for the main harness, that could cause a problem with how the gauges read. Check the wiring on the back of the gauges.<br />If you go running new double wires to the gauges, you are only covering up the actual problem that will show up in something else later. Might as well fix it right the first time and be done with it.<br /><br />Heres a trouble shooting guide from Teleflex.<br /> http://www.tflx.com/pdf/tempsy~1.pdf

 

[allen.st]

Re: Cruising RPM Stringer 800

Thanks Don, Yes I agree that the ground may be the problem but I don’t trust either of the gauges at this point. I thought that by replacing both and a new sensor I would be starting off with something sure (well at least it should be “LOL”). The reason for using 2 wires from the sending unit of equal lengths would be to ensure that I did not get more resistance on one which I would think that would make the reading different or would it be so small that it would not be noticeable? At this point if I still had a problem I could take it further such at tracing and cleaning ground wires, checking water flow again and so on but at least it would be a good starting point and the cost of new gauges and sensor is much cheaper than a new engine “LOL”

 

[KaGee]

Re: Cruising RPM Stringer 800

Originally posted by Scuba Diver Texas:<br /> KaGee, this engine does not seem to want to start unless the throttle is set at about 4,000 and it wont idel under 1,000 so I will add a carb rebuild kit to my upcomming order.

You are asking for trouble if you don't get that fixed. Going from a dead start to 4000 RPMS ?? Bad, Bad, Bad!! As I stated before..over 700 RPM idle (preferably lower) and you will have problems with the guts of that Stringer! Just a matter of time.

 

[supercab78]

Re: Cruising RPM Stringer 800

Scuba Diver Texas;If I remember correctly my owners manual for a 1975 190hp OMC says not to excede 4200 rpm on the outdrive. Do you still have points in you distributer? Some good old basic tuning may take care of your engine problems. You could temporarily install a mechanical(car type) gauge back on the engine just to see what your true temp is. Is it a Holley carb. on it? If so a 2 or 4 barrel?

 

[allen.st]

Re: Cruising RPM Stringer 800

Thanks Supercab78, yes the distributer still has points, I have replace points, condenser, and cap. I got the dwell set but I am still soaking the distributer (it wont rotate) so I can set the timing "LOL"<br />It has a Holly 4 bbl that I am trying to find a kit for, I think Sierra has one.

 

[supercab78]

Re: Cruising RPM Stringer 800

SDT: You may be able to get a carb. kit from a good auto parts place. My holley two barrel uses the same gaskets and internal parts as my old Holleys used on my cars. If you are unable to get your dist. loose and your timing is close, one degree in dwell timing will change your ignition timing 2 degree "I hope I remember that correctly"

 

[jimmythekid]

Re: Cruising RPM Stringer 800

i used an air hammer, pb blaster, to loosen a dist on a 460 ford, lube with pb and then with pair of pliers or small pipe wrench apply pressure to dist housing and then give a couple of light blows straight down while turning and it should loosen. I cant over emphasize LIGHT BLOWS

 

[allen.st]

Re: Cruising RPM Stringer 800

SC I got a carb kit from Shipstore.com, I also got both temp gauges and a fuel gauge with senders from them at a very reasonable price compared to West Marine "LOL"<br /><br />JTK I got the nasty distributor loose with several applications of WD40 and lots of light tapsd over 2 weeks. Once I found the timing marks and cleaned the Harmonic Dapner and marked my 10 BTDC it was a breeze.<br /><br />Took boat out today and with my new temp gauges it still gets hot but not as fast as it used to show and both gauges read the same. So now I guess it is time to change thermostats and pull the exhause and go through them "S"

 

[allen.st]

Re: Cruising RPM Stringer 800

I also found out both my upper and lower tac's are reading twice the rpm ie boat tac's read 2,000 but with 2 different tac's i only get 1,000. I cleaned all connectors and checked the wiring along with the 4, 6, or 8 clynder swithces and all seems to be order. go figure a 29 yr old gauges going bad??? "LOL"

 

[supercab78]

Re: Cruising RPM Stringer 800

SDT; I think you could"i've not ever done this myself just so you know" take the hose that is coming up from your outdrive pump (should be the long hose coming up from the back of engine with a 90 degree curve in ) off of the top of themo housing. Then while in water start the engine -for a few seconds- and check the flow of pump in lower unit. <br /> I have found this style impeller to be very durable in my boat. Over 300 hours & still in good shape.<br /> My boat has a cap on outdrive to hook a hose to for flushing or running. I left it off once and I started overheating. If your lucky maybe your just missing that cap.

 

[Boomyal]

Re: Cruising RPM Stringer 800

Originally posted by Scuba Diver Texas:<br /> JTK I got the nasty distributor loose with several applications of WD40 and lots of light tapsd over 2 weeks.

If you'da used a real penatrent, it would have taken you a couple of days instead of a couple of weeks. WD40 is a poor lubricant and a poorer penatrant. It's only good for keeping your channel locks from rusting up.<br /><br />As for the RPM for your outdrive, if in good shape it will handle whatever the maximum rpm that your 351 is rated for. (4400 to 4800 rpm)