1977 Johnson 35 not getting gas?

[flintcreek]

First bought this boat last year and have never had it run right. Compression is 140. It has new coils and jumps spark 7/16". It will crank and run for a short time when you choke it and then die. Pumping the bulb on the hose does not help. I borrowed my brothers tank and hose (known good) and it did not help. I am able to spray fuel mix in the carb and it will stay running. I have cleaned the carb with no change. I have also put a known good carb and fuel pump off another 35 that I have with a bad clutch dog and it makes no difference. What am I over looking. I have noticed when cranking with the choke closed it pops open when turning the motor over. Reed valves or other thoughts. Could it still be in the firing, it is CDI and I am not sure how to use a DVA meter. Ideals would be appreciated. I am about ready to carry it to a mechanic.

Flintcreek...

 

[boobie]

Re: 1977 Johnson 35 not getting gas?

How did you clean the carb and was the other one you put on good and clean. Still sounds like a carb prob.

 

[mrcj001]

Re: 1977 Johnson 35 not getting gas?

Dirty carbs....dirty or failed fuel pump.....fuel tank not vented.....

 

[flintcreek]

Re: 1977 Johnson 35 not getting gas?

I took the carb and took out all of the knock outs and high speed jet and sprayed it down and blew it out. Took a carb off a good running 35 with a bad clutch dog and it still won't run. Fuel tank is new along with fresh 50 to 1 mix, vent open. Took the fuel pump off the good running 35 also. I have built 10 or so Johnson carbs and never had this problem. I cleaned every passage. Gasket around center post of carb looks good.
I am starting to think fix the clutch dog on the other motor and put it on this boat may be easier.

Flintcreek

 

[fireman57]

Re: 1977 Johnson 35 not getting gas?

Are you sure that no hoses have cracks in them that are letting air in? Are you sure that you are even getting fuel to the carbs?

 

[flintcreek]

Re: 1977 Johnson 35 not getting gas?

Carried it out to 2 of the best boat motor mechanics in the area this afternoon. They double checked me on the carb, and confirmed the carb is getting gas. Took the front plug out for the high speed jet and fule dumped out. Checked all hoses, fuel pump and all. One of the mechanics said he had a 25 doing the exact same thing, he had replaced the top and bottom seals and everything else he could think of but had not fixed it yet. He said if he figured his out he would call me and let me know what he found and we could try it on mine. Right now I am trying to figure out how to test it to see if it is pulling vacuum to get the gas from the carb to the cylinders. I tried not to make the post too long but one other piece of info that could be real important. When I bought the motor it had a blown head gasket, could this have done something else that causes it to not pull gas to the pistons? Compression is 130 on both cylinders now.

Thanks,
Flintcreek

 

[flintcreek]

Re: 1977 Johnson 35 not getting gas?

Played with this thing some more today after reading the section on here about how to test the fuel delivery system a couple of times. Put a piece of clear pvc line in lline between the fuel pump and carb, it did not ever fill all the way up had alot of air in the line. Checked fuel pressure about 1.5 lbs pulse out of the fuel pump. Looks like to me that I am not getting the right amount of fuel to the carb from the fuel pump, possible air leak some where. By passed the fuel pump and just tried to get it to run pumping the bulb to feed the carb gas and this did not work. Tomorrow I am going to get my brothers fuel tank and line and try it after checking all of my lines on the motor. I have already replaced these if my memory serves me right. I started to work on this motor several months ago, and then got tied up with basketball, so it is hard to remember for sure.

Flintcreek

 

[Cofe]

Re: 1977 Johnson 35 not getting gas?

Awhile back I used a Seirra kit to rebuild a carb. The washer under the float needle valve seat was too thick. I would have had to do some serious bending on the float to get it set right. I ended up using the old washer. Also the new kits have rubber tipped float needle valves that stick.....I have read several posts since then that they are having the same problem with the float needle valve sticking closed......Hope this helps

 

[flintcreek]

Re: 1977 Johnson 35 not getting gas?

It has a Sierra kit in it with the rubber tipped float needle, I will take a look I may have a good looking old style solid brass needle and seat for this size motor. Might be the problem. Does a OMC kit have the solid brass needle? I may have to go to the shop and look at my 3 hp. kit it is a OMC kit.

Thanks,
Flintcreek

 

[Cofe]

Re: 1977 Johnson 35 not getting gas?

My old needle is stainless steel.

 

[glengold]

Re: 1977 Johnson 35 not getting gas?

I broke down last weekend with my '77 55hp. Found a stuck needle in the seat. I've posted about this on the forum with no response. I just rebuilt both carbs with the stupid rubber-tipped needles, and a month later one was stuck! Where can we find "non-rubber-tipped" needles!!!

 

[flintcreek]

Re: 1977 Johnson 35 not getting gas?

Glengold, I did check out my OMC kit for my 67 model 3 hp. and it has a solid stainless needle. I have about decided this could be the only thing left to do is rebuild my carb using a solid stainless needle, I am going to look and see if I have a old needle and seat that I can try tomorrow. I am also going to call my local Johnson dealer and order a carb rebuild kit tomorrow.

Flintcreek

 

[flintcreek]

Re: 1977 Johnson 35 not getting gas?

Bought a new OMC Carb Kit and went back through the carb. The OMC kit has a solid stainless needle, no rubber. Motor is still doing the same cranks runs just a little and dies. You can keep working the choke on and off and keep it running for a while. Any Ideals?
Flintcreek

 

[flintcreek]

Re: 1977 Johnson 35 not getting gas?

Talking to my son at breakfast this morning, he is a Chevy mechanic and he said he would take a look at it with me this morning. So we go out an hook it up to water and fire it off....he is checking it out while I am keeping it running (working the choke). He suggest try a old electric fuel pump I have laying down in the shop. We hook it up and get it going and still it dies. He picks up some carb cleaner and starts spraying the motor down while I am operating the choke to keep it running. When he sprays over behind the stater on the right side of the motor it smooths out. Shut it off and crank it again and he sprays it on the intake gaskets behind the starter again it smooths out. Looks like I need intake gaskets. I am going to see if I can pick them up from my local Johnson dealer Monday. We will see.

Flintcreek

 

[jasper60103]

Re: 1977 Johnson 35 not getting gas?

So, it sounds like it's part #2 on pic?

Thanks for the update.

 

[flintcreek]

Re: 1977 Johnson 35 not getting gas?

I am replacing #2 and #12....not sure which gasket is bad.

Flintcreek

 

[flintcreek]

Re: 1977 Johnson 35 not getting gas?

Update, I have now replaced the intake and bypass gaskets. When you spray the outside of the block it does not change the way it runs like it did earlier, but problem still not fixed. The motor still cranks after choking runs for about 10 seconds they you have to choke it again to keep it running or spray fuel mix into the carb. Tomorrow I am going to do the following things.

1. Check fuel pump, pull fuel pump off motor and leave connected to the fule line pump fuel line and look for fuel to come out the back side.
2. Put a clear fuel line from the fuel pump to the carb, so I can see what is going on. Should this line stay full all the time?
3. Businees card 1/2 to 3/4 inch in front of the carb should vibrate or oscillate if reeds are good, if they are bad they should get gas on it.

My brother has promised tomorrow to bring his boat and motor which is a 35 hp 78 model Johnson which has the same carb and fuel pump. I plan on switching these out and seeing what happens.

Any ideals? I am at my witts end. Help!!!

 

[flintcreek]

Re: 1977 Johnson 35 not getting gas?

Well my brother came by and brought his boat and motor so I was able to borrow his carb and determine that I have a carb problem. We mounted his carb on my motor and it runs great. Put mine back on and it runs for a few seconds and goes dead. We both took my carb and took all of the knock outs out and checked everything. We could get to and it looks clean. There is one thing that I may have done wrong in the carb rebuild. The carb kit came with a small plastic piece that showed to go over the end of the low speed needle, I put this in. I have managed to take it back out and have put it back together, will be tomorrow before I get to try it out. The piece I am talking about is not shown in the attached picture...I may post a new post about the carb and see if anyone else has ever had this problem. Thanks to everyone for your help. I will make a follow up post tomorrow and let everyone know it this fixes it. If it does not I may be looking for a new carb.

Thanks,
Flintcreek

 

[77 johnson 35]

Re: 1977 Johnson 35 not getting gas?

Well my brother came by and brought his boat and motor so I was able to borrow his carb and determine that I have a carb problem. We mounted his carb on my motor and it runs great. Put mine back on and it runs for a few seconds and goes dead. We both took my carb and took all of the knock outs out and checked everything. We could get to and it looks clean. There is one thing that I may have done wrong in the carb rebuild. The carb kit came with a small plastic piece that showed to go over the end of the low speed needle, I put this in. I have managed to take it back out and have put it back together, will be tomorrow before I get to try it out. The piece I am talking about is not shown in the attached picture...I may post a new post about the carb and see if anyone else has ever had this problem. Thanks to everyone for your help. I will make a follow up post tomorrow and let everyone know it this fixes it. If it does not I may be looking for a new carb.

Thanks,
Flintcreek

View attachment 91319

WHATEVER HAPPENED? im having the same issue

 

[175se]

Re: 1977 Johnson 35 not getting gas?

that small plastic piece you put on the needle valve (bearing needle valve-is what it is called) could be whats causingyour issue,it does not appear to be used on yours.