1975 135 Evinrude Carb Sync Difficulties

[Speedy4]

Hello,
I bought a 1975, 135 Evinrude recently, so I have no real history on it. It did start and idle but did not see it run in the water. Compression was 115-120 in all 4 cyclinders, so i figured it couldn't be all that bad off. I noticed the lower carb was leaking out the front when tilted, so I rebuilt both carbs with a kit. Used H.P. air and all seemed clear. It started easy and idled ok but fell flat under a load and open throttle.
From a suggestion on here, I did a carb/timing sync. From what I could figure out with the manual, the advance cam timing was really out of adjustment, by alot. Now the motor runs smooth from about 1/4 throttle up to WOT.

My problem is it is hard starting after sitting over about 2 hours. Won't start without starting fluid. But after the first start, It keeps starting. When it does start it idles rough and sometimes spits back up to somewhere around 1/4 throttle.
I still seem to be seeping from the lower carb. Took it back off, did the float adjustment again, bowl gasket, low speed jets clear. Still seeping, Still hard to start.

I am thinking I have multiple problems. Flooding for the hard starting? Carb sync or low speed fuel supply for the rough idle.

Any Suggestions?
Can anyone tell me another way to sync the carbs/timing then what is in the manual? I am following the instructions but it still just doesn't seem right.

Thanks,
John

 

[Solittle]

Re: 1975 135 Evinrude Carb Sync Difficulties

What manual are you using? The OEM is the best.

 

[Speedy4]

Re: 1975 135 Evinrude Carb Sync Difficulties

The Evinrude Factory Service Manual.

It just seems that the Idle/Advance scew is to far in, I have almost no adjustment left. The cam roller is also about 1/16 of an inch of the throttle cam at idle. So when I put it in the start position it doesn't open the throttle plate.

I'm not sure if this is normal. My first motor of this type and have nothing to compare it too. When following the manual I really had to make alot of adjustments, like everything was really out of wack.

This motor also has no low speed idle screws, so I am guessing the carbs have to be just about perfect and the sync dead on.

It's probably just me and lack of experience.....

 

[emdsapmgr]

Re: 1975 135 Evinrude Carb Sync Difficulties

Where is the carb leaking? Your phrase "When it does start it idles rough and sometimes spits back up to somewhere around 1/4 throttle." could be a Lean Sneeze. This could be caused by high timing at idle. Also, check for a broken or cracked reed.

 

[Speedy4]

Re: 1975 135 Evinrude Carb Sync Difficulties

Yes, a lean sneeze. Didn't really know how to describe it. It looks like the fuel is coming from inside the throttle bore. Hard to tell it is just seepage but over time when sitting I can see it wet on the outside of the carb and in the air silencer. There is also wetness under the carb on the lower motor cover.

As far as the high timing, it could be after I did the sync/advance adjustment. But following the manual it is set at the 5 degrees. I didn't take the leafs out to check, trying to rule out everything else first before I take it apart.

Before the sync adjustment, it started and idled ok, but no WOT without nursing the throttle up. Now good throttle but hard start and poor low speed.

 

[eli_lilly]

Re: 1975 135 Evinrude Carb Sync Difficulties

The Evinrude Factory Service Manual.

It just seems that the Idle/Advance scew is to far in, I have almost no adjustment left. The cam roller is also about 1/16 of an inch of the throttle cam at idle. So when I put it in the start position it doesn't open the throttle plate.

The throttle cam has a screw that, when loosened, will allow you to adjust the assembly so that the cam roller will intersect the cam at the line when at idle.

The idle advance screw position is fine if your idle timing is within spec. From what I have gleaned from posts here, the idea of the screw is to back the timing down if the idle is too high.

-E

 

[Joe Reeves]

Re: 1975 135 Evinrude Carb Sync Difficulties

The throttle butterflies should start to open exactly when the scribe mark of the cam is aligned exactly with the center of the carburetor cam roller SO loosen the locking screw and adjust it to be so..... not before or after.

Remove the carburetors again. In back of the screws/bolts on each side of the float chambers is a fixed brass high speed jet, located in the bottom center portion of that float chamber.... four of them in total. Clean them manually with a piece of single strand steel wire.

The slow speed jets (4 of them) are located behing the small aluminum screws that are located at the rear sides of the top carburetor bodies. Run a .031 drill thru them to clean them out. CAUTION, DO NOT use any other size drill !

If you haven't already, install new complete carburetor kits which include new float needle valve assemblies.

(Carburetor Float Setting)
(J. Reeves)

With the carburetor body held upside down, the float being viewed from the side, adjust the float so that the free end of the float (the end opposite the hinge pin) is ever so slightly higher (just ever so slightly off level) than the other end. And when viewed from the end, make sure it is not cocked.

 

[Speedy4]

Re: 1975 135 Evinrude Carb Sync Difficulties

Thanks Joe,

Should I take the gasket in account? The one that came out was thin paper type, the one in the kit is a thicker rubber type.

Any good hints on how to set, seal and check the core plugs in the float chamber?

Thanks,
John

 

[tashasdaddy]

Re: 1975 135 Evinrude Carb Sync Difficulties

totally surprized someone hasn't reemed you, yet about using Starter Spray. it is the 2 cycles worst enemy, has no lube and strips the lube on the surfaces of the engine, and burns to hot. can burn a hole in a piston, really quick. use some premixed gas in a squeeze or spray bottle if you need the starting boost.

 

[Speedy4]

Re: 1975 135 Evinrude Carb Sync Difficulties

I have been using this.

http://www.maximausa.com/products/misc/mppl.asp

 

[Joe Reeves]

Re: 1975 135 Evinrude Carb Sync Difficulties

Use the rubberized type gaskets that come with the kit. However, these have nothing to do with the float level setup.

 

[burroak]

Re: 1975 135 Evinrude Carb Sync Difficulties

.....Run a .031 drill thru them to clean them out. CAUTION, DO NOT use any other size drill !....

That is a #68 at any hobby shop.

 

[CARDNAL98]

Re: 1975 135 Evinrude Carb Sync Difficulties

i have the same outboard as you a 1975 135hp evinrude. i had the same prob the way i fixed my carbs took them off motor took them apart removed all the jets and and float i put carbs in bucket with gasoline for a few days make sure that carbs are coverd with gas that will remove any gunk on them. after few days took them out and blew them out with air . and before i put back together if you look inside carb at the side that fits up on to the intake flip the flaps and you will see 4 small hole clean them with a welders tip cleaner spray some carb cleaner threw the side where jet gose and you will see it sray trew the 4 holes. then blow out with air put all jets back needle float then just bend your float up just a little from flat put back on motor should fire right up whith no prob just make sure that carbs are good and tight because if they are not you will get air and that will make your motor caugh and spit just like mine did. my budy works at boat shop and that is what he told me to do and now my outboard runs great thanks to my budy brian hope this will help you good luck.

 

[Bifflefan]

Re: 1975 135 Evinrude Carb Sync Difficulties

The Evinrude Factory Service Manual.

It just seems that the Idle/Advance scew is to far in, I have almost no adjustment left. The cam roller is also about 1/16 of an inch of the throttle cam at idle. So when I put it in the start position it doesn't open the throttle plate.

.....

When the repair shop did my carbs, they had to find a longer screw to put in, as mine is old and worn, alot.
Mine too was way out to lunch and i just couldnt get it, thats why i took it in so it was done right and then i knew what right looked like.

 

[mikeymo27]

Re: 1975 135 Evinrude Carb Sync Difficulties

Greetings from Long Island!

I too have the motor and recently while I was full throttle it bogged down really bad. I just recently bought the boat and the owner said that he sometimes has to use the starting fluid to get the thing going. From the time I bought it, I could never start the motor WITHOUT the starter fluid. It would start right up and was ready to go after I sprayed. Then this happened. I have since changed the fuel pump, cleaned out the carbs the best I could with a wooden skewer (I'm not too mechanically inclined so this new to me. my friend has been helping as well.) The lower carb unit's gasket was not good so I replaced that. I put it all back together again it wouldn't start unless we choked it (we have to do it with our hand, the choke isn't hooked up) and again, it would not go to higher RPM's. And there was a steady stream of fuel coming out of the lower carb. Did I ruin the motor by using the spray?

Any advice would be greatly appreciated. Thank you.

Hello,
I bought a 1975, 135 Evinrude recently, so I have no real history on it. It did start and idle but did not see it run in the water. Compression was 115-120 in all 4 cyclinders, so i figured it couldn't be all that bad off. I noticed the lower carb was leaking out the front when tilted, so I rebuilt both carbs with a kit. Used H.P. air and all seemed clear. It started easy and idled ok but fell flat under a load and open throttle.
From a suggestion on here, I did a carb/timing sync. From what I could figure out with the manual, the advance cam timing was really out of adjustment, by alot. Now the motor runs smooth from about 1/4 throttle up to WOT.

My problem is it is hard starting after sitting over about 2 hours. Won't start without starting fluid. But after the first start, It keeps starting. When it does start it idles rough and sometimes spits back up to somewhere around 1/4 throttle.
I still seem to be seeping from the lower carb. Took it back off, did the float adjustment again, bowl gasket, low speed jets clear. Still seeping, Still hard to start.

I am thinking I have multiple problems. Flooding for the hard starting? Carb sync or low speed fuel supply for the rough idle.

Any Suggestions?
Can anyone tell me another way to sync the carbs/timing then what is in the manual? I am following the instructions but it still just doesn't seem right.

Thanks,
John

 

[emdsapmgr]

Re: 1975 135 Evinrude Carb Sync Difficulties

The carb roller should be spaced slightly away from the cam at idle-so the carb butterflys are both closed. For instance, you should be able to slip a thin pc of paper between the two. Follow Joe's advice on the roller/cam alignment. The idle timing degrees are to be used when initially setting up the engine prior to finally setting the idle rpm's. Once running, set the idle rpm's when the boat is floating in the lake and it's in forward gear. Set the screw on the spark advance lever so that it idles between 650 and 700 rpm's. Once the idle is set, likely the idle timing will have changed. Don't worry about that. Regarding hard starting-does the choke solenoid fully close the choke plates when the key is pushed in? You'll have to pull the airbox cover to visually check it. While you are looking, make sure both throttle butterflys are closed-look the same- at idle. I've been lucky over the years. My carbs have cleaned up without having to remove the core plugs in the upper carb body. You should try to clean them without removing. A carb cleaner like a Gumout product is the only cleaner which will dissolve dried fuel gel from the carb's passages. Gas won't do it. If you do remove those core plugs, you'll have to use Gasoila sealer around the core plugs when you reinstall them.

 

[Joe Reeves]

Re: 1975 135 Evinrude Carb Sync Difficulties

Has nobody noticed? This thread is over six (6) years old!

Time to start a new post!

 

[mikeymo27]

Re: 1975 135 Evinrude Carb Sync Difficulties

Gentlemen,

Thanks so much for the advice. We are going to look into the steps you've indicated but we decided to tackle the gas leaking from the lower carb problem, just to eliminate that (and hopefully solve the issue). So we took the lower carb apart again, it was the one spitting out gas, and adjusted the plunger float so it would seat correctly (it was out of whack a bit). No more gas leaking! So we thought it was good to go. It would not start initially, so unfortunately we had to use the ether and it started right up. With the throttle up, it didn't initially hit High RPM's and when it did, it did for about 20 seconds and shut down. It was difficult to restart again so we used the ether and it would not hit that high level RPMs from then on. Now the motor was surging, misfiring and shutting down.

My buddy initially checked for spark using that light tool and it passed that test so we assume it's not spark related. Also wanted to mention the the prior owner only used it in fresh water.

Again, thanks so much for your help. I'm learning as I go with this and appreciate your wisdom. In my research I found that these might be possibilities.
Flooding cylinders
Head Gasket
Need to drill out the carb jets
Adjust Trunnion coil
Power pack heating up and failing
Clogged pick-up in fuel tank (but the problem still occurred even when I used an external gas can)

This problem happened suddenly, when I was in full throttle. It bogged down and will not hit high RPMs since then.

Thanks,
Mike

The carb roller should be spaced slightly away from the cam at idle-so the carb butterflys are both closed. For instance, you should be able to slip a thin pc of paper between the two. Follow Joe's advice on the roller/cam alignment. The idle timing degrees are to be used when initially setting up the engine prior to finally setting the idle rpm's. Once running, set the idle rpm's when the boat is floating in the lake and it's in forward gear. Set the screw on the spark advance lever so that it idles between 650 and 700 rpm's. Once the idle is set, likely the idle timing will have changed. Don't worry about that. Regarding hard starting-does the choke solenoid fully close the choke plates when the key is pushed in? You'll have to pull the airbox cover to visually check it. While you are looking, make sure both throttle butterflys are closed-look the same- at idle. I've been lucky over the years. My carbs have cleaned up without having to remove the core plugs in the upper carb body. You should try to clean them without removing. A carb cleaner like a Gumout product is the only cleaner which will dissolve dried fuel gel from the carb's passages. Gas won't do it. If you do remove those core plugs, you'll have to use Gasoila sealer around the core plugs when you reinstall them.