Merc 650 1971 Various problems need advice

"Hi all,

Like to say, i hav

"Hi all,

Like to say, i have gone through a lot of these threads, and your advice has been very usefull thus far.

I am new to the whole scene, and i need some advice on my unit. I know its a 1971 650 from its serial number. I bought the boat with the motor complete from my Brother, almost a year ago. Since that time, it has not run for a full 6 months, when i briefly started it up, to see if it still runs, and not since then.

Now i tried working it this weekend again, to get it running for good now, and get it certified. However i am having difficulties starting the unit now.

Firstly, the choke on the motor (manual and electronic) is not working.

Secondly, i cannot disengage the gearbox from forward, to Neutral nor Reverse.

I think also the carbs are dirty from the old fuel in the tank.

My question is this. How difficult is it to remove the lower unit, to get to the shifting mechanism? http://www.marineengine.com/discus/messages/12479/334438.png"" alt="""">

I found this image in another thread. Does the main shaft, the shifter shaft and the water pipe all come out without a problem? Is their anything special i should take note of when removing the unit?

Second question. Will the motor struggle to start when the gearbox is engaged? I had it running shortly, but it dies after a short while, then i struggle to get it to start again. Could this be becuase of the lack of a choke, or posibly a dirty carb?

Also, does anyone maybe have the part names of the parts numbered in the picture above?

Alot of questions i know, but i hope someone may be able to help me.

Thank you in advance."

"If it shifted okay before, do

"If it shifted okay before, do NOT mess with it. (The shift mechanism works much better with the motor running, by the way.)

I'm amazed you got it started without the choke working--mine starts hard WITH it working. Either the choke button is shot, the solenoid is fried, or you have a bad connection. Start at the solenoid--jumper it with 12 volts and see if it works. If so, work backwards from there.

Jeff"

"Actually, the shifter never w

"Actually, the shifter never worked....till today

I opened it and fixed it, so now i have neutral and reverse once more.

Now, as for the choke, it also never worked

I checked the solenoid coil today, and it seems good, i just need to wire up the switch which is currently disconnected.

But i still think their is a bigger problem. Possibly the timing on the distributer? Or dirty carbs?

How difficult is it to clean out the carbs, or adjust the linkage between the throttle and the distributer?"

"Heinrich,if you haven't t

"Heinrich,if you haven't touched the timing, it is unlikely to be out,I would say get yourself a manual,this site sells them,Seloc,up on the right hand corner.
If this motor hasn't been started in some time,a compression test ,spark,carb rebuild,fuel pump rebuild,impeller change,lwr unit lube change and the lower unit will usually slide off,hopefully, ,some put it in fwd before they take of the unit,I put mine in neutral,doesn't matter as long as both motor and unit are in the same gear when reassembling"

"The carbs on that beast are H

"The carbs on that beast are HELL to get off, so if you can run carb cleaner through them, by all means do so.

Jeff

PS: I had to butcher grind an old 7/16 open end to get those ~@*!* carb nuts off. And congrats on getting the shifting fixed."

"<[img]"http://www.marineengin

" Jeff's right there about those nuts.Seeing as I don't have the daintiest of hands I took off the front support bracket and starter,well I had time on my hands and I wanted to keep the skin on them as well,but try Jeff's advice on the carb cleaner first,might be easier"

"Thanks for the advise guys. W

"Thanks for the advise guys. What i will do today is fix the push button choke, and try and run more of that carb cleaner through. I also think when the battery gets low from all the fail starts, the start spark will be low? (Seing as the "alternator" isn't generating enough current at start yet?)

So i will replace the battery with my wifes car's battery, and try the whole lot again today and see.

P.S. i read in another post on these forums that someone said that the linkage for the distributer can easily move out of position, giving the spark to early or to late when adjusting the throttle. Is this true."

".." will replace the batt

".." will replace the battery with my wifes car's battery"

Carefully, carefully!

The linkage is not your problem. It not only does not move out of position, it's tough to adjust. one of Merc's more poorly designed systems with a plastic slider piece that breaks way too easily. (After two broke on me, I made a steel one that won't.)

Jeff

Jeff"

"Yes thank you, i did actually

"Yes thank you, i did actually check that now when i went for lunch at home. That arm cold not have moved, it is way too tight down.

I have another question though. If i pump up my bulb for the fuel prime, should fuel be coming out the top of the carb hole? (Not butterfly, the very top, has a small hole)"

"Ok, my daily update. So now i

"Ok, my daily update. So now i have a working push button choke, and i redid some wiring going into the distributer that where looking bad. Changed the battery, and checked the spark, and it looks great.

However, i cant get it to start in either full throttle, no throttle, in or out of gear, and all combinations with the choke in.

As before if i pump fuel with the bulb, it comes out the top little hole on the carb, is this normal? Could my main problem be all carb related?"

"Hennrich it won't/shouldn

"Hennrich it won't/shouldn't start in gear,fuel leaking anywhere from carb,not good,carb rebuild mind those knuckles.
Is there still fuel at the plugs? Check those fuel lines for cracks,maybe a pinhole in the fuel pump diaphragm.
Now the dumb question,are you using the warm up lever when trying to start the motor?"

If they are Tillotsons they ha

If they are Tillotsons they have a choke. The odd ball carbs that came with some Merc triples had an enrichener deal.

I suspect the idle passages of your carbs are clogged like the Holland Tunnel at rush hour!

Jeff

PS: Fired up my '75 triple just today. Started in 2 or 3 seconds and idled without stalling--but it has clean carbs.

Were'nt the 1971 650's

Were'nt the 1971 650's 4 cyls?Or am I wrong again? What's yours Heinrich? And they had Tillotsons.

"Yeah, it is a 4cylinder 2 car

"Yeah, it is a 4cylinder 2 carb setup, and it has a choke. I dont think its the fuel pump, becuase if i turn the starter motor for a long while, i can see the fuel coming out the same hole in the top carb as when i pump up the bulb.

I think i'll be taking of the carbs tonight, and see if i can get them cleaned out. If the float was sticking, the fuel would have come out the butterfly wouldn't it?

Anyways, thanks for the help thus far."

"Oooohhh! It's a 4 cylind

"Oooohhh! It's a 4 cylinder, not a triple. Good. Much easier to work on.

Jeff"

"If it is leaking at the top o

"If it is leaking at the top of the carb, the wee gasket under the bolt is gone,if there's ahole there and no bolt ,you're missing a bolt,if there is a bolt and a hole,there's one hole too many. You'll need a new cap for your carb."

"Stripped of both carbs last n

"Stripped of both carbs last night, and it seems the bottom carb's needle and seat would never have been able to close with the float, as the leaf spring pressing plate was bent slightly. Thus the bottom carb will always be getting fuel, regardless of float. However, that was not the carb that was leaking fuel out the top.

The top carb, i now know, was leaking fuel out the "overflow" hole, at the top of the float chamber. Now, i did clean out the whole carb, and i checked the needle and seat and so forth, but i honostly cant see why the fuel would have came out their, if the float is working correctly.

Will let you know what happens, when i get it back on the boat again today."

"The needle and seat were leak

"The needle and seat were leaking by--a common problem. Being a legendary cheapskate, I carefully remove the rubber seat, turn it upside down, and put it back together.

The procedure is then: Re-set the float height--the bottom arm should be level--and pressure test it in a vise. If it still leaks, drop the float level a tad more. When it won't leak regardless of how hard you pump the bulb, then it's ready to go back on the motor.

Jeff"

"Hi again, time for an update.

"Hi again, time for an update.

I did clean and take of the carbs. The needle and seat works correctly, as i can pump all i want, and it does not come out the carbs anymore. Also check that the fuel pump works, which it does.

Re-did almost all the wiring to ensure the spark is strong, which it is. BUT, i still can get it to run :/

I am on my wits end, so i am giving up, and taking it into a shop to get it working. Will let you all know what the problem was."

Did you keep pulling and clean

Did you keep pulling and cleaning the plugs? That's often necessary in cold weather.

Jeff

"yeah, tried basically everyth

"yeah, tried basically everything i could think off. My problem may be bigger than i had hoped."

"It MIGHT be out of time someh

"It MIGHT be out of time somehow.

If it's getting gas and spark, got compression, clean plugs, and it's spinning over fast enough, then it's gotta start!

Jeff"

"Heinrich,are the plugs wet? I

"Heinrich,are the plugs wet? If not possible reed problem.To see the reeds you need to pull the carbs.again,GENTLY press each petal in slightly in case some of them are sticking.The bad news is that if it is a reed problem,you need to split the powerhead to sort it.Time consuming but not really difficult. http://www.crowleymarine.com/mercury_parts/450/12.cfm Did you do a compression check? What were the numbers? I know I said if you haven't touched the timing it shouldn't go of but check it for fun. Do link and sync. on the carbs if you haven't already done it."

"Thats my problem, i have no t

"Thats my problem, i have no timing light, or anything to do a compression test with :/

Id rather stop messing around and get it done properly now. It is going in tommorow."

"Those items aren't that e

"Those items aren't that expensive in an auto factors shop compared to what a marine shop will charge you,if you can get one to work on a motor that old,plus you have the satisfaction of saying "I did it myself""

"Guess who is back, and is hav

"Guess who is back, and is having to fix the problem himself anyway

The mechanic wanted to charge me way too much to fix the problem, so its back to me to get it working.

First thing i would like to know, whould you guys be able to ship parts to South Africa if i wanted to buy kits and parts from the website?

Secondly, back to the problem. I have been informed that the compression is fine. I am getting proper carb cleaner product, so i will most likelly be removing the carbs again to clean. I think also i will be changing the coil as i think the wire from the coil may be problematic, and the coil itself.

I do not think the coil on the unit is the correct one as well, it may be of another model. What type of coil should i get for this unit? I cant seem to find my serial number under your electrical catalogue.

Last question for now

"Do link and sync. on the carbs if you haven't already done it."

What does that mean?"

"Hi Heinrich,Do link and sync.

"Hi Heinrich,Do link and sync. on the carbs if you haven't already done it." It means that when the distributor advances that the carbs. open at the correct time.When #1 cyl fires as the timing mark on the flywheel.(3 white dots) passes TDC mark on the timing decal,the throttle arm on the distributor should just be touching the arm on the carbs, But I suggest a manual to guide you through that. http://www.crowleymarine.com/mercury_parts/450/7.cfm #45 is the coil.If you cross ref it with CDI or sierra.But if you have a strong spark at the plugs it is unlikely to be the coil.Spark should jump 7/16".Test those plug leads as well for cracks. Check the distributor cap for cracks/damage.Have a look at the spring loaded brush in the center of the cap inside,if its damaged,it needs to be replaced.
Andrew who runs this site ships manuals international but not parts.
www.dougrussell.com www.eastcoastmarineservices.com may help."