1976 35hp chrysler- dies @ idle & WOTsurges

[phree_1]

I have a 1976 35HP outboard Chyrsler model #357HK.<br />It will not idle in neutral, it dies.<br />It also surges in WOT. <br />Sometimes it runs fine at WOT, other times it runs at trolling speed with power surges.<br />I do have a Seloc repair manuel.<br />I first thought it was a firing issue. I replaced all coils, plugs(gapped correctly), plug wires.<br />I now think it is a fuel issue.<br />I used fresh gas. I re-built the carb(Tilloston- WB). I flushed all fuel lines. The primer bulb hardens and stays pressurized. <br />I still haven't fixed the problem.<br />I am now thinking it may be the fuel pump? I was thinking about running a fuel pressure check between the fuel pump and the carb?<br />I talked to a local mechanic and he said "that if the primer bulb stays pressurized that it is not the fuel pump" I'm not really sure about what he said?<br />I'm in need of some help. I've been working on this problem off and on for over a year now.<br />Anybody have any thoughts?

 

[eurolarva]

Re: 1976 35hp chrysler- dies @ idle & WOTsurges

If you are in the US go to NAPA and get a fuel pump rebuild kit part number 18-7806. It costs about 10 bucks. When you take the pump apart you want to replace the diaphram and gasket. This is a very easy task. You may have a broken or defective fuel seat that may be giving you problems, but for now just replace the diaphram, gasket the gasket of the fuel bowl and replace the screen if one comes in the kit. There will be three small gaskets for the fuel seats which probably wont fit. You can replace the one that the two screws are holding down but dont mess with the press fit ones. If your motor does not show improvement you may have to replace all three of the fuel seats. They are 5 dollars a piece and the correct gaskets for them are fifty cents each and can be purchased from a merc dealer. If you need help finding these part numbers post it here and I will give you the numbers. You should also replace all of your fuel lines and clamps. I think your mechanic is wrong concerning the fuel pump. If your needle valves in your carbs are working correctly the primer bulb will still get hard because the system is closed. Even with a tear in the fuel pump diaphram the system is still sealed and the bulb will stay hard.

 

[WillyBWright]

Re: 1976 35hp chrysler- dies @ idle & WOTsurges

I'd say go ahead and rebuild the fuel pump. I don't think it's your problem, but it's plenty old to need doing anyhow. I had a puzzler very similar to this. Same model and about the same age. Flywheel magnet turned out to be weak. Have you had the flywheel off? Is there a lot of rust between the laminations?

 

[phree_1]

Re: 1976 35hp chrysler- dies @ idle & WOTsurges

eurolarva,<br />I checked with Napa. The part number you gave me was correct! The price was $7.49 and they have one in stock. I will pick it up later today.<br /><br />I called a couple of local marines about the three fuel seats. I thought I would also replace them. You were correct in the fact that they are Merc. part numbers. The only problem is they don't know which part number it is yet.<br /><br />WillyBWright,<br />I haven't had the flywheel off yet.<br /><br />Thanks everybody, I'll let you know how it goes.

 

[eurolarva]

Re: 1976 35hp chrysler- dies @ idle & WOTsurges

Tell the merc dealer these part numbers are Quicksilver numbers. The fuel seat is called a check valve part number 21-F177330 and the gasket is part number 27-F84792. I took these part numbers off the spare one I got from Mercury.

 

[phree_1]

Re: 1976 35hp chrysler- dies @ idle & WOTsurges

My wife and I live on Lake Tenkiller. She was bitten by a Copperhead on Wednesday evening.<br />The local hospital life flighted her to Tulsa.<br />We are still there and hope she gets released on Saturday.<br />I did get the part from Napa on Wednesday morning. But I haven't been home to work on the boat.<br />I'll let you know hiow things go soon.<br />Thanks

 

[tmlavigne]

Re: 1976 35hp chrysler- dies @ idle & WOTsurges

Actually, I bet that it probly isn't anything to do with fuel. Take your flywheel off and see if the plate that the coils are attached to will move easily or not. It might be partly ceased. I think that you probly have some kind of electrical problem. Check and make sure that the grounds for the coils and condensers are not loose. That is where I would begin if you've already done all the fuel stuff...

 

[tmlavigne]

Re: 1976 35hp chrysler- dies @ idle & WOTsurges

I forgot to add. You could have a bad coil or a weak pick up for the magnets. Good luck.

 

[phree_1]

Re: 1976 35hp chrysler- dies @ idle & WOTsurges

My wife got out of the hospital Sunday. I've have been very busy playing nurse. She still can't walk from the snake bite on her ankle. The hospital wasn't going to release her until she could walk, but I told them otherwise, because we don't have insurance. <br />I did manage to sneek out and replace the fuel pump diaphram. It may or maynot be the problem, but I hope it is. I still haven't had time to put the boat in the water yet. Hopefully I will have time soon.<br />Thanks for all the help. I could not afford a mechanic now. I'm guessing this will be about a $40,000 snake bite. <br />I'll let you know how it goes.

 

[eurolarva]

Re: 1976 35hp chrysler- dies @ idle & WOTsurges

Bummer on the snake bite. I hope all goes well with you and your wife. Pretty bad when insurance costs more than your house payment but that is the case. Good luck. I hope it is the water pump too but even if it isnt it is one of the cheapest things in the troubleshooting procedure. When you have the fuel pump apart check out the three fuel seats. Look closely to see if you can see the gaskets and see if they are broken. Also use a nail or something similar and push on them to verify the springs are working on them. Use the non pointed side of a finishing nail if you have one. Good luck to you and your wife

 

[phree_1]

Re: 1976 35hp chrysler- dies @ idle & WOTsurges

I took the boat out last night. It ran fine for about an hour and then started power surging in WOT.<br />It did need the carb. rebuilt and it did need a new fuel pump diaphram. Unfortunatley, I still haven't found the problem.<br />The good news is-When I got home last night,I killed another Copperhead 15 yards from the front door.

 

[scotiany]

Re: 1976 35hp chrysler- dies @ idle & WOTsurges

I'm wondering if the puddle valve-breather drain system has a clogged screen. It's easy enough to check and clean. It will cut out at low speed and run on 1 cylinder. Usually the lower plug will foul out. I've had that problem on my '70 55hp. There should also be a check valve in one of the drain hoses. At least there was on mine. But, '72 and later model recirculated the fuel mix back into the system somehow.