Stalls when throttling up in back pressure ....Help needed

[fishfeatures]

1990 60hp johnson

senario is ;
It'll idle on muffs, in a test barrell and in the river
It'll run in gear on muffs (not to be done i know) ,
it'll run in gear in a test barrell
It WON'T run in the river once throttled is applied it'll just die out.

What has been done and checked and rechecked is
Carb's rebuilt inc welch plugs (carbs taken apart several times to be checked), premix sprayed in and intakes covered to see if any chages happened but nothing.
new fuel lines ,
pump inspected and disassembled ( no leaks)
Good spark tested with air gap of 1/2"
Cylinder drop test carried out and is even results across all 3
good compression, head was even removed last night to make sure no water intrusion just to be sure.
Lync and sync done too many times to rememeber


It'll troll in gear at it's lowest speed, but once power is applied it'll die. have tried pumping the bulb to rule out the pump and it still happened. That's why i questioning if it's an exhaust issue and maybe it's smothering itself somehow?
It'll rev up in the river in neutral but once i put it into gear and go past idle it'll die .

Please help am at my wits end with this thing now.

 

[durban]

Re: Stalls when throttling up in back pressure ....Help needed

so now you are left with stator ,censors & power-pack . i would change the stator & sensors first [timer& base] or do one at a time starting with the stator .

 

[fishfeatures]

Re: Stalls when throttling up in back pressure ....Help needed

so now you are left with stator ,censors & power-pack . i would change the stator & sensors first [timer& base] or do one at a time starting with the stator .

P/P is a brand new one as I was getting intermmitent spark and non spark probs earlier in the year.

What effect would a bad stator have on the motor? Is it not just there for charging ? How would it know the difference between motor in and out of water?

Parts #8 and #49 then I'm after ...yes?

http://epc.brp.com/Index.aspx?lang=E&s1=3226433d-c55c-47bc-95d6-78db65ded209

 

[oldcatamount]

Re: Stalls when throttling up in back pressure ....Help needed

Wow, you've gone through the whole thing! The only thing I can think of is an ignition short when the shifter is moved and the throttle is advanced. Run it in a barrel (or muffs) and watch the movement (if any) of the coil wires/plug wires when you engage the gears and move the throttle. Maybe you'll see a spot that's getting pinched or is frayed. Just guessing here, but that's what I'd try at least.

 

[fishfeatures]

Re: Stalls when throttling up in back pressure ....Help needed

At this stage Oldcatamount I'll try any thing, what i have i got to lose except the hair on my head that I am sloly pulling out.

Just had a look and replacement prices for stator and WOW! they ain't cheap, sure hope I don't have to swop them.

 

[durban]

Re: Stalls when throttling up in back pressure ....Help needed

i would buy a 1970 ties 60 to 75 hp 2nhd stator for 50dlrs on ebay it will fit , all you have to do is fit a plug on the 2 wires there where yours has it , because they did not come out with a plug on them in those years , 2 wires go to rectifier & the other 2 wires go to power pack , the stator does have something to do with spark & as well as sending power to rectifier for battery charging , the senors pick up the signal when the strips in flywheel pass the censor & the current is then sent to the power pack & the stators job is to supply power to the power-pack then to coil , then spark plug , sorry iam not a auto electrician , so i cant be of much help , but this is what i will do , start changing stator first , cheap 50dlrs .

 

[daselbee]

Re: Stalls when throttling up in back pressure ....Help needed

Press the key in just as you throttle up. This will tell you if it is too lean under load to continue to accelerate.

 

[durban]

Re: Stalls when throttling up in back pressure ....Help needed

the current the stator pushes out is determined by the speed the flywheel turns , the stator knows when the motor is not in the water , the flywheel tells the stator how much current to push out by the speed it turns , so i would say it turns faster out the water , & when its in the water under-load , different speed , something like this .

 

[daselbee]

Re: Stalls when throttling up in back pressure ....Help needed

Sorry d-man....gotta disagree.

Go back and re-think.

 

[durban]

Re: Stalls when throttling up in back pressure ....Help needed

one of 2 things or both , insufficient spark , when throttling up or to much fuel to plugs ,& spark not big enough to ignite the fuel . my guess your chess game , ha . i hope he gets it fixed , its frustrating when the fish are on the bite .

 

[fishfeatures]

Re: Stalls when throttling up in back pressure ....Help needed

Press the key in just as you throttle up. This will tell you if it is too lean under load to continue to accelerate.

Pushing in the key doen't change the issue i have. If the lower unit shift lever is not attached then it'll throttle up fine in the water. Once attached it'll revert back to it's usual issue.

 

[fishfeatures]

Re: Stalls when throttling up in back pressure ....Help needed

i would buy a 1970 ties 60 to 75 hp 2nhd stator for 50dlrs on ebay it will fit , all you have to do is fit a plug on the 2 wires there where yours has it , because they did not come out with a plug on them in those years , 2 wires go to rectifier & the other 2 wires go to power pack , the stator does have something to do with spark & as well as sending power to rectifier for battery charging , the senors pick up the signal when the strips in flywheel pass the censor & the current is then sent to the power pack & the stators job is to supply power to the power-pack then to coil , then spark plug , sorry iam not a auto electrician , so i cant be of much help , but this is what i will do , start changing stator first , cheap 50dlrs .

You're def sure a 1970 one will suffice ?

 

[daselbee]

Re: Stalls when throttling up in back pressure ....Help needed

Not being critical....you are certainly the thinker....

Consider this. The electronics of the powerpack are driven by the stator output of the charge coils.
(We are not discussling the coils used to charge the battery. That is a separate function.)

The stator charge coil output VOLTAGE (not current) increases with rpm. But the current that the PP and trigger uses remains
fairly constant. It does go up slightly, but these are active components and the effective resistance (impedance) of the PP and trigger must remain almost constant for the electronics to work the same at all speeds.

The current required must be fairly low. This is shown by the very small wire size used to wind the charge coils...I guess about number 20 wire which is small. That wire cannot flow much current, but it can handle higher voltages easily.

Anyway, you are correct.....he MIGHT have a borderline condition of weak spark. I thought he tested spark....if he hasn't, he should.

I usually try to post suggestions that cost nothing and are quick and easy to try.
He could rule out a lean condition very very easily by pushing the key in....assuming his primer system is working, of course...

Keep up the good fight down there buddy. I have not been to NZ, but I have seen documentaries. What a beautiful country.


EDIT: Well I see that I am wrong. He just posted that pushing the key in doesn't help.
I wonder....does the engine stall when idling if you push the key in? If not, primer system is not working right, and the test is not valid, cause you effectively did not richen it up....anyway...good luck.

 

[fishfeatures]

Re: Stalls when throttling up in back pressure ....Help needed

If not, primer system is not working right, and the test is not valid, cause you effectively did not richen it up....anyway...good luck.

daselbee , Due to cracked pick up tubes I had to swop my carbs out for an old set of 70hp ones I had (the ones with the butterfly choke) so I've no primer setup. The carbs worked fine on the motor they were removed from. Should have mentioned that in first post , sorry.

 

[durban]

Re: Stalls when throttling up in back pressure ....Help needed

You're def sure a 1970 one will suffice ?

the 1970 models came out with a distributor from 1974 they came out with the stator like you have now ,but they fitted the plug where its on your one , so buy one from 1974 & up

 

[daselbee]

Re: Stalls when throttling up in back pressure ....Help needed

daselbee , Due to cracked pick up tubes I had to swop my carbs out for an old set of 70hp ones I had (the ones with the butterfly choke) so I've no primer setup. The carbs worked fine on the motor they were removed from. Should have mentioned that in first post , sorry.

OK then....you will have to have a helper. Have someone drive, with the cowl off, and as he accelerates, manually give it some choke.
Thats all I wanted to test...to see if it was lean on acceleration. So you choke it a bit and see if that cures the die out problem. You will have to experiment with how much to choke it, but it will probably be alot of choke.

And, you have mid to late 70's era carbs on a 1990 60 hp. OK...... So the output of the primer solenoid that normally feeds into the intake, or possibly into the top of the carbs.....where does that output go? Is it clamped off, is the primer solenoid gone, what up????

And, did it ever run right with the 70s era carbs on it? Is this a problem that is being caused by mismatched parts?

 

[daselbee]

Re: Stalls when throttling up in back pressure ....Help needed

I posted that up pretty quick, and have since had other thoughts.

First... Ok you press the key in....what happens? Even with the choke system, it should clunk as the chokes close.
And if so, it should be enrichening the mix at that point. Does that even happen, or is total manual choke?

Secondly, have you examined very thoroughly the carb to intake mating surface, looking for any holes, passages, channels, etc. that are on the newer carbs that are NOT on the older carbs? Study both the old carb and the new carb for differences.

Thirdly, the mixture at the intermediate speed range (between idle and when the main jets start to draw) could be entirely different from the new to the old carb. Could be....maybe that is why it dies.

Fourthly, I have rebuilt 1979 thru 1985 carbs with cracked pickup tubes, and I used them anyway. The engines run fine...no problems so far. Maybe it is where they were cracked, and how wide....but are you sure the cracked pickup tubes were really a problem with the newer carbs? If so, why?

 

[durban]

Re: Stalls when throttling up in back pressure ....Help needed

one more thing i would try if every thing else doesn't fix it go up & down in jet sizes

 

[fishfeatures]

Re: Stalls when throttling up in back pressure ....Help needed

I posted that up pretty quick, and have since had other thoughts.

First... Ok you press the key in....what happens? Even with the choke system, it should clunk as the chokes close.
And if so, it should be enrichening the mix at that point. Does that even happen, or is total manual choke?

Secondly, have you examined very thoroughly the carb to intake mating surface, looking for any holes, passages, channels, etc. that are on the newer carbs that are NOT on the older carbs? Study both the old carb and the new carb for differences.

Thirdly, the mixture at the intermediate speed range (between idle and when the main jets start to draw) could be entirely different from the new to the old carb. Could be....maybe that is why it dies.

Fourthly, I have rebuilt 1979 thru 1985 carbs with cracked pickup tubes, and I used them anyway. The engines run fine...no problems so far. Maybe it is where they were cracked, and how wide....but are you sure the cracked pickup tubes were really a problem with the newer carbs? If so, why?

Daselbee primer removed and replaced with the choke solenoid for the older carbs.
Carbs were working fine on the motor they came off, which suffered gearbox damage due to some rather large submersed trunks.I see no concern in using them.
Motor will still die if choked, but you must remember that the remote will push on through the rpm range if the gear lever is disconnected or it'll run on muffs no bother.. So i know that the carbs are getting fuel at high speed. Once gearbox is attached the issue arises so once the engine comes under strain from having to turn the gears it'll then bog.

Original carbs would not idle what so ever kept surging really high in idle position and then die. I reckon that the idle pickup tube in one or more has to be damaged somewhere but I'll inspect them and prob reattach them over the weekend to be double sure.

 

[fishfeatures]

Re: Stalls when throttling up in back pressure ....Help needed

ok . have got lucky, about time.
I have picked up a scrapped '92 evinrude 60hp with a scored middle cylinder. It is complete with everything except t&t. I got it really cheap from a lovely old gent who wanted to get rid of it out of his garage. He bought it new but the thing was caked from salt water deposits no wonder it failed, the middle cylinder was caked all around with the stuff. I don't think it was ever flushed once and it has VRO with all original fittings even the filter is the original , he never had it serviced once I reckon.



So I've got new carbs which I'll soak tonight and clean tomorrow. Am waiting for a harmonic puller to arrive in the post so I can pop offf my original fly wheel and swop timer or stator if i need to .

hopefully I can get this prob sorted over the weekend. fingers crossed....