some starting and running problems
Hi all i have a 1976 johnson 70 hp 2 stroke 3 cyl and was looking for some help. The motor will run like a dream once it is started sometimes can take up to around 30 turns and almost a flat battery to get it going?? it doesent seem to be pumping to much fuel as there is no slick on water when trying. also after ive head out and found some ground to fish (not to far) it will some times start with no issue but if i give it to much throttle it will just stall and i have to travel at 4-5 knots for about 5 mins and then very gently apply the throttle. do you think this is related? i have fitted new plugs, new water pump housing and impeller, also new main jets to carbs stripped them down and cleaned all new gaskets ect. the two needles seem to have been removed??? seats stll in place so i have no needles to adjust (i was very confussed) not sure if this is normal practice on these old motors?????? any advice or help would be much apreciated thanks Dan
aalfred
Posts: 669
Date Joined: 13/06/09
I had the same problem with a
I had the same problem with a old evinrude. we did all the same things and nothin realy worked." Start ya bastard" spray helped a bit. When we took the engine apart we could see that the pistons where burned through to about 60 percent. That might had something to do with it. Never worked again.
Hope u can get it fixed....
soupster51
Posts: 2724
Date Joined: 29/11/06
Starter Motor
On old engines starter motors are often the problem. Pull your starter motor off and apart. The brushes may be on a coiled spring, and being so wear away against the rotor. This in turn fills up the body of the starter motor with carbon. Once you have it apart spray everything with 'contact cleaner', force all the soot out and you should be right. Have a look at the brushes and see if they need replacing. If they do you then have two options, replace the brushes or buy a new/recon starter motor. This may or may not help. I hope you get it running either way.
The best reason for doing what's right today is tomorrow.
franke
Posts: 32
Date Joined: 02/08/10
needles
you are talking about the needles for the floats arent you??
if so how the hell do you stop fuel over filling the bowels and flooding the engine??
poida
Posts: 234
Date Joined: 08/08/05
How many carby's does it
How many carby's does it have? And i presume it has a manual choke???
Sounds like a fuel probem, put some petrol in a squirty bottle and squirt down carby while cranking over, this will tell you if its a fuel delivery problem or not.
I take it you have set the mixture, might be running lean???
Check compression and timing.
chris raff
Posts: 3257
Date Joined: 09/02/10
Sinking a few bit of money and time in a old donk
I suppose you just have to weigh it up vs buying a new / new 2nd hand one ...I want to be confident I'd be coming home every trip..otherwise stripping and cleaning carby replacing needles and seats and working back from there hoses bulb etc...being what sounds like a fuel related issue...anyways my 5c worth goodluck
“Intelligence is like a four-wheel drive. It only allows you to get stuck in more remote places.”
fishfish
Posts: 307
Date Joined: 01/09/09
two stroke starting
If your having problems starting from cold then I would suspect compression issues, If your were missing the needles out of the seats in the carbies then the engine would flood both on the bulb and running ,,, Any history on the motor ie how long have you had it??? just bought it ???? etc
styleascoot
Posts: 21
Date Joined: 23/09/07
Thanks for the replies
Thanks for the replies guys
Franke im not sure how or why the main jet from float bowl was in and have now replaced with new but the needle that would be at the top of the carb believe the idle needle? or low speed needle? was not in place just the seat at the bottom of the hole all nicely screwed in?? and the same at the bottom of the carb from the float bowl (not the main jet) so i was thinking along those same lines is this engine just flooding its self?? its just a nightmare in for a perfect weekend to take here out but unsure if its worth the risk
fishfish just bought the boat a few months ago as a unregistered tub its an old swiftcraft of some sort? at a massive 4.6m lol that i thought would make a nice little project so give it a big once over all new paint, windows, bimini, new electrics, seats the whole lot all is good just this motor issue. and it has sucked the savings so cant realy aford a new motor.
So if any of you guys are heading out of mindarie over the weekend not to far and want to show me your prized grounds lol, and if need be tow me home send a message lol.... cheers guys
sandbar
Posts: 704
Date Joined: 25/10/09
Agree with fishfish, compression.
Good bet its just the head gasket. $15 and some mechanical know how and she'll be sorted. Bloody good donk so won't be major. I had very similar problem.
stilly
Posts: 341
Date Joined: 10/08/09
wow a carb with a needle not in its seat
will never.......ever even start, and you are doing well not to be on fire if it does, i would suggest if you have had the carbs apart and have touched idle mixture screws (you would have if you played with the carbs) to get someone with an ear to set them, sounds like idle screws to me, your floats should be set from factory no reason to touch them needles should be set to level when holding your carb upside down,, mixture screws on an engine that age will never all be set the same hope this helps