MarineEngine.com - Your best connection for marine engines, parts, service, and information. View Cart / Check Out Contact MarineEngine.com Ordering and Shipping Information Free Engine Classifieds Engine Parts Discussion Board Engine Manuals Home / Directory
add bookmark or favorites | email this page
Topics Topics Edit Profile Profile Help/Instructions Help Member List Register  
Search Last 1|3|7 Days Search Search Tree View Tree View  

1970 CHRYSLER 70HP MAGNAFORCE IGNITIO...

Discussion Forum at MarineEngine.com » Chrysler Force Outboard » 1970 CHRYSLER 70HP MAGNAFORCE IGNITION PROBLEM « Previous Next »

Author Message
Top of pagePrevious messageNext messageBottom of page Link to this message

PAUL E
New member
Username: squibs

Post Number: 1
Registered: 10-2009
Posted on Sunday, October 18, 2009 - 01:42 am:   Edit Post Delete Post View Post/Check IP

Hi, just bought a 1972 phantom boat. It came with a 70hp chrysler engine. The engine runs fine, but it has trouble starting. Sometimes the engine will backfire when it tries to start. It takes at least 5 tries, with priming, before the engine will start. When the engine does start, there is no problem. I have changed the spark plugs with b9hs-10 from cabelas and changed the spark plug wires. I have no idea how an outboard works. I bought the boat for $300, so I don't really want to spend much to fix the engine. Is there a simple way to fix this problem, or should I hire a mechanic to fix it.
Top of pagePrevious messageNext messageBottom of page Link to this message

Bill Smith
Advanced Member
Username: ko4nrbs

Post Number: 223
Registered: 06-2006
Posted on Monday, October 19, 2009 - 07:19 pm:   Edit Post Delete Post View Post/Check IP

Any motor that has sat for a while will need attention. My brother in law has that same motor and it runs well. I suggest you do or have the following done.
1. Rebuild carburetors and syncronize the linkages.
2. Rebuild fuel pump (may be your problem).
3. Clean the points or replace them.
4. Replace the water pump. Don't take a chance on an unknown pump impeller. It's only rubber!!
5. Change oil in lower unit. If it is milky colored you will have to reseal the lower unit.
6. Buy a good maintenance manual for it.

Use Seafoam in the gas with the correct oil mixture. Seafoam will clean up the fuel system well. Get it at WalMart in the automotive section.
You can do all of this with basic mechanical skills and some help from the guys here.

Franz at Franz Marine is a good source for help as well.
Find him here:
http://www.geocities.com/thechryslercrew/

Bill
Top of pagePrevious messageNext messageBottom of page Link to this message

Bill Smith
Advanced Member
Username: ko4nrbs

Post Number: 224
Registered: 06-2006
Posted on Monday, October 19, 2009 - 07:34 pm:   Edit Post Delete Post View Post/Check IP

One thing I forgot:

Before sinking a lot of moeny into it check the compression in each cylinder. Should be around over 100 psi and no more than 10% difference between cylinders. My brother-in-law's is 135 psi.
Top of pagePrevious messageNext messageBottom of page Link to this message

PAUL E
New member
Username: squibs

Post Number: 2
Registered: 10-2009
Posted on Thursday, October 22, 2009 - 10:08 am:   Edit Post Delete Post View Post/Check IP

Thanks for the help. I checked compression and each cylinder was 120psi. I had the carburetors rebuilt. Tried to start the engine and it did the same thing. Finally my friend told me to try another battery. I did and it started right up. He told me I had to trickle charge the battery when I wasn't using it. So, it starts right up now, but now I have a new problem. Is gas supposed to come out of the exhuast? I have the water hose hooked up to the engine, but I can tell gas is coming out with the water. Is that normal?
Top of pagePrevious messageNext messageBottom of page Link to this message

Bill Smith
Advanced Member
Username: ko4nrbs

Post Number: 226
Registered: 06-2006
Posted on Thursday, October 22, 2009 - 05:55 pm:   Edit Post Delete Post View Post/Check IP

Unburned fuel/oil mix is normal in the exhaust especially running on muffs or in a barrel. It should be mixed up with the cooling water discharged. I'd also rebuild the fuel pump. It's simple and inexpensive to do.

Even though you have it running I'd do a good tune up and replace the water impeller.
Top of pagePrevious messageNext messageBottom of page Link to this message

PAUL E
New member
Username: squibs

Post Number: 3
Registered: 10-2009
Posted on Friday, November 20, 2009 - 12:41 am:   Edit Post Delete Post View Post/Check IP

Well, I finally had to take the engine to get repaired. At $85 an hour I found out that 1. the starter had a "loose bolt" which is causing it to draw double the amp to start, 2. The number 2 carburetor is flooding at idle, 3. all carbs are externally leaking at idle 4. the engine requires 2 cycle mix to run (i was putting regular gas in there), and 5. the fuel pump is going bad, so might as well replace it.
Top of pagePrevious messageNext messageBottom of page Link to this message

steve
Member
Username: steveog

Post Number: 6
Registered: 11-2009
Posted on Friday, November 20, 2009 - 09:16 am:   Edit Post Delete Post View Post/Check IP

Paul
by 2 cycle mix be you mean that you havent used a 2 stroke oil mix ie just run on neat four stroke,as if you have even for a short time it may have knackered the motor ie no oil on the moving parts.
Top of pagePrevious messageNext messageBottom of page Link to this message

PAUL E
Member
Username: squibs

Post Number: 4
Registered: 10-2009
Posted on Friday, November 20, 2009 - 12:25 pm:   Edit Post Delete Post View Post/Check IP

Yeah, i ran it for about 10 min without the mix in the gas, but the repair guy took the engine apart and said it was good. he inspected the pistons, crankshaft, and piston walls. he said it was fine.
Top of pagePrevious messageNext messageBottom of page Link to this message

steve
Member
Username: steveog

Post Number: 8
Registered: 11-2009
Posted on Friday, November 20, 2009 - 01:53 pm:   Edit Post Delete Post View Post/Check IP

wow thats good luck,coz normally its good night for the crank & pistons.

i put a non snythetic oil in my motorcross bike and the motor lasted 10 mins on normal road use.

now i always over oil & and by the best oil,as it cheaper than bores & pistons and depression !
steve

Add Your Message Here
Post:
Bold text Italics Underline Create a hyperlink Insert a clipart image

Username: Posting Information:
Only registered users may post messages here. Registration is FREE and easy, click on the REGISTER link at the top of the page. Thanks.
Password:
Options: Automatically activate URLs in message
Action:

Administration Administration Log Out Log Out   Previous Page Previous Page Next Page Next Page


Home / Directory | Engine Manuals | Engine Parts | Discussion Board | Free Classifieds | Orders / Shipping | Contact Us | View Cart

About Us | Terms of Use | Privacy Policy
MarineEngine.com, 184 Jones Dr., Brandon, VT 05733 USA
Phone: 802-247-4700 FAX: 802-301-1034 info@marineengine.com
Copyright © 2000 - 2007 by MarineEngine.com, Inc. All rights reserved
   
Traduca
EspanolEspanol
Traduisez
FrancaisFrancais
Traduza
PortuguesePortuguese
Traduca
Italiano
Ubersetzen
Deutschen