'94 70HP EVUNRUDE FRUSTRATION!

Andrew Brierley · Mar 12, 2003

Re: '94 70HP EVUNRUDE FRUSTRATION!

Motor get hot quite quickly so I believe the thermostat is ok. However, I will change it just in case, there is nothinf else left to try. I replaced the fuel pump yesterday and it still does not sound any better. of course I won't really know until it goes in the water. It may have fixed it but I doubt it. When idling, it runs kind of smooth for 1 - 2 seconds and then sort of pops or puffs and then runs smooth again for 1 - 2 seconds and so on.

Andrew Brierley · Mar 12, 2003

Re: '94 70HP EVUNRUDE FRUSTRATION!

Bill, just a thought but dpminc lives in Minnesota, I have been there, it is a hell of a lot colder then Australia. Where I am putting my boat in, the water temp is 74 DegF. The baot should warm up very quickly. I am insanely jealous of those boaters that turn up and start their engine once and drive off while I am sitting there trying to get my to run long enough that I can put into gear without stalling

Valv · Mar 12, 2003

Re: '94 70HP EVUNRUDE FRUSTRATION!

Modcat, Minnesota is cold in winter, but our boat season starts in may and after 2 months we reach water temp of 70degrees too. I seems you don't like the suggestions they provided you, checking thermostats is not a big deal, easier than rebuild carbs. Low compression of 90 on 125 is bad. You have a problem motor and you are hoping it will go away with a simple solution, it won't. I know dpminc, it's a heck of a mechanic, he works for a business which deals with 1,000s of motors and I/O, that's all it does. I would tear motor down, buy a manual and start from scratch.

Andrew Brierley · Mar 23, 2003

Re: '94 70HP EVUNRUDE FRUSTRATION!

Excuse me??? What do you mean I don't like the suggestions? I have followed every suggestion made here so far, I have replaced the Fuel lines, fuel bowl, fittings, and overhauled the carbies. I have put on a new head gasket and I have a Thermostat on backorder. To quote: "Motor get hot quite quickly so I believe the thermostat is ok. However, I will change it just in case, there is nothing else left to try" The cylinders are now 125, 110, 125 since the head gasket change. The motor startes easily and runs very well so long as I allow plenty of time for it to warm up (Lending credence to the thermostat theory) The only remaining problem is that it dies when I try to accelerate when the motor has not had a long time to warm up ie 2 - 3 minutes at fast idle. I am not looking for the easy way out. The previous owner paid no attention to maintenance and as such the engine did not have a single major fault but many many minor faults as a result of neglect. I changed the gearbox oil yesterday, looked like it was the original from factory it was that gunky and full of water! So far I have only had to spend $150 to get everything running very well. This motor is old and done a lot of hours, I could have gone straight to the new rings and pistons overhaul at a cost of $1200 (Quoted) only to have the Gearbox fail the next day. If this should happen to me soon then I have not wasted $1200! Valv, the tone of your message is to put me down and imply that I am not listening. If you have nothing constructive to add, then add nothing.

Valv · Mar 24, 2003

Re: '94 70HP EVUNRUDE FRUSTRATION!

Modcat, I followed this therad all the way, everybody gave their best to help you, but you criticized somebody since season is different from you. I don't want to star an argument, but you have to understand it's very tough to troubleshoot without even looking at motor. I still think your compression is bad, 90lbs on middle cylinder is no good. I also have a 70hp 3 cyls like yours (thet's why I was following thread) and it runs like a top, but it's a 1976. All you did was great for your motor, but you might have to come to conclusion it might have some more serious problems. I don't want to insult you, and forgive me if you felt that way, it's just sometimes it's hard to bite the bullet when you "shell" out many $$ for something you think it was a simple fix or a good buy. I do buy many outboards and boats at auctions, for as much as I can be sure they are ok, there is always the "doubt" on them and I have to be careful. On my side I also have a OMC 115hp which has great compression but has same symptoms as yours. So, let's shake hands and try to figure out these "buggers"...(if you were closer we could have a beer together to "forget" these darn outboards) I saw a signature from a user once, and I thought it was one of the best: "God created man, and the Devil created the Outboard" (or something like that.

BillP · Mar 24, 2003

Re: '94 70HP EVUNRUDE FRUSTRATION!

I live in Florida and can say from first hand experiece that OMC outboards (75 & 140) can run too cold at idle (cough and sputter) without the tstat working properly. The water temp is in the 80s.

Andrew Brierley · Mar 24, 2003

Re: '94 70HP EVUNRUDE FRUSTRATION!

Ok Guys, as I said, I have ordered the Thermostat, already got the springs and gaskets etc but the thermo is on Backorder at Bombardier. The young bloke who works with me, just so happens is Dad works at Bombardier, been really handy for me

When I get the thermostat and install it, how much difference will it make to warm up time, will it warm up within a minute or is it going to take 5 or 6 minutes? One more thing, the Guys at Bombardier tell me it is very common for the Thermostat Bolts to break when trying to remove them due to corrosion, is this your experience also? If so what would you recommend to limit this possibility to a minumum risk. I was thinking about soaking for a couple of days with penetrating oil and then maybe tapping with a hammer a couple of time to break the seal before trying to unscrew them. What do think? Andrew

jim dozier · Mar 24, 2003

Re: '94 70HP EVUNRUDE FRUSTRATION!

There are many good posts on broken bolts. Do a search. To answer your question. Yes, yes, yes and they may break anyway.

BillP · Mar 24, 2003

Re: '94 70HP EVUNRUDE FRUSTRATION!

On really bad situations penetrating oil doesn't work. I cycle the parts with a heat gun and then ice. Heat the part around the bolt and put ice on the bolt. Tap them and rock back and forth too. Do this for a half hour and let cool a few minutes in between. I use those bags you freeze for ice. If that doesn't do it you are stuck...break out your center punch, drill bit and easy out. Use the easy out before wringing the bolt off.

G DANE · Mar 24, 2003

Re: '94 70HP EVUNRUDE FRUSTRATION!

Hi Modcat I couldnt resist to jump in. If your compression jumped to 110 in the mid hole I do not believe this is you problem. Did you soak the carbureators in the cleaning solvent ( not gas ) overnight when you cleaned them ? this sounds like a classic restriction in iddle circuit to mee. Remember the dirt you want to remove is hidden behind the small iddle orifices and hidden in the small internal passages in carb body, limitiding flow only led by atmosphere pressure. Soak and clean after 12 Hrs with air compressor. Watch your eyes ! Bet it will solve your problem. Beware of air leaks between carb/manifold too.

G DANE · Mar 24, 2003

Re: '94 70HP EVUNRUDE FRUSTRATION!

And Andrew I would advice you to leave the thermostat untill you redone the carbs and sync´n linck procedure by manual, if your operating temparature seems OK, no need to mess with broken bolts if you can avoid it.

sparkroost · Mar 24, 2003

Re: '94 70HP EVUNRUDE FRUSTRATION!

I believe you need to synk your carbs! that hore**** procedure in the manual is just that. Most have 1 piece non adjustable linkage. You can get a turnbuckle and the necessary hardware at a RC hobbie store. the linkage wears out and the plates don't open at the same time. If you have a bad cylinder it can be almost impossible. Why don't these carbs have a vaccum port for synking?!?

Andrew Brierley · Mar 30, 2003

Re: '94 70HP EVUNRUDE FRUSTRATION!

Changed the Thermostat, went out on the lake on Staurday and it looks like 95% of my problems are history. So long as a wait a few minutes for the motor to warm up I have no problems. It idles and it accelerates really well. I just wish it would accelerate easier when still cold. It is a pain to have to start and warm up everytime I want to move on up the lake a few hundred meters. Can't complain any more though as it seems reliable now so long as I give the warm up period. Thankyou all for your help, specially the Thermostat suggestion. The old Thermostat by the way was totally stuffed and locked in the closed postion (I was expecting open position) the bypass springs were pathetically weak in comparison to the new set. I would guess they were letting all the water bypass all the time. the seals were stuffed as well. I would not mind betting that the previous owner had never ever changed it. regards Andrew Happy Boating! PS. I also found an excellent fishing spot for some nice size Bream in Lake Illawarra so it was an all around good weekend.

Andrew Brierley · Apr 1, 2003

Re: '94 70HP EVUNRUDE FRUSTRATION!

Took my boat out again, still went well but the back of the trailer just about fell off when I put the boat back on AAAAAAARRRRRRRHGHHHHHG! When will it all end

I guess this ends this thread, so bye y'all See you in the next thread, about fixing trailers maybe

'94 70HP EVUNRUDE FRUSTRATION!

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