Picked my brain tooo much. Totally stuck. Chrysler 75hp, early 80's. 2 stroke problem

M

matthew1981

Cadet
Joined
Sep 6, 2011
Messages
6
Hiya everybody
I have been having a few probs with a boat i bought from ebay (i know... bad idea,lol). So the engine starts ok. Sometimes have to turn key 3/4 times to get it started. It idles and revs perfect... for about 20/30 seconds. Then it seems to loose it's revs. No matter how hard i push the accelerate stick down it dosnet make any difference. It just idles slow then it cuts off. Bit hard to start back up. Although it does... For a very short time then stalls. So far i have changed the cooling propeller, got rid of all old petrol. Put in new petrol and oil. Mixed spot on 50/1. Checked all fuel lines. Checked the fuel filter.(Line must be ok between here and petrol tank as the filter was full of fuel. No debris in fuel filter. I have noticed that once engine has started and run for a while the prime bulb goes down a little. Not like a vacuum though that many others report. Just maybe 3/4 full (like before you prime it). i Checked over all electrical wiring and all looks good. Today i took out all 3 carbs and have cleaned them. Going to put them back in tomoz. I have also checked compression. Its all fine. One thing i have noticed, I have read up that it could be the coil. I am going to get a multi meter to test the coil on monday. So what do you guys advise after i put the carbs back in. The spark plus have also all been changed. Another thing, 2 spark plugs always have dark fuel on them and the other spark plug has more clear looking fuel on it. Any advice would be a great help. Im totally stuck and dont wnat to pay a mechanic a fortune to have a look when i feel i can do it myself. Thanks everybody.
Matty

Also one more thing.
The boat has a rev counter and heat dial. Neither are working. I have gone through wiring and from what i can see they are both wired correctly. Any idea's ??
 
eurolarva

eurolarva

Rear Admiral
Joined
Jun 24, 2003
Messages
4,182
Re: Picked my brain tooo much. Totally stuck. Chrysler 75hp, early 80's. 2 stroke pro

Rebuild fuel pump
 
B

bentle

Chief Petty Officer
Joined
Aug 2, 2011
Messages
492
Re: Picked my brain tooo much. Totally stuck. Chrysler 75hp, early 80's. 2 stroke pro

How's the compression on each cylinder. You may want to check that. Low comp will make fuel pump,pump less fuel. Also check fuel lines from tank to carbs and the fuel pickup tube in the tank. Fuel vent must also be free and able to vent properly. As already stated the carbs may need to be sinked so they are working together as well as air fuel adjust fine tuning. Floats may also need adjusting. Make sure timing is correct and that the timing linkages are functioning properly. One other is check for good crisp purple spark to each plug. Good luck and get us know how it goes.
 
M

matthew1981

Cadet
Joined
Sep 6, 2011
Messages
6
Re: Picked my brain tooo much. Totally stuck. Chrysler 75hp, early 80's. 2 stroke pro

Thank you everybody for your support and guidance. Not getting much luck asking the marine engine shops round here (uk). As soon as i say chrysler i get such a look. So i fitted new carbs. I changed the whole set to another set the guy i got boat from gave me. A big difference. Ticking over alot better. Faster than before but more stable. I have checked all pipes. One was totally blocked. Done think it was anthing major. Was a pipe between air filer and bottom of carbs. Think maybe for when petrol gets in air filter to take the fuel back to carb. After i started engine and it was running i checked all spark plus. I noticed that only the top cylinder had smoke in it. The other 2 had no smoke at all. In regards to the compression. I used my neighbours compression tester. From what i read in manual the readings were in the range and not much change between all 3 of them. I am going to buy a compression tester on monday as will need it for the future and to recheck .Bentle, I still have to check for spark. Im a bit spooked because last time i played about with a spark plug i got a nice jolt,lol. MInd you that was about 10 years ago. As i fitted new carbs i checked the links on both sides and they were all closing together. Read from manual so i didnt go wrong. I am hoping that it was the rich/ lean screws that were out as with new carbs it was purring over nice but old carbs were more like farts after a curry,lol.
I have tried to take fuel pump out. Very hard to even move bolts. Painted over by previous owner.

Thanks again everybody. Tomoz got to get some carb gaskets as the old ones i used were leaking. So tomoz ill check for sparks, change gaskets in carbs and hopefully get those bolt out so i can get fuel pump out.
Also looked at rev counter and engine temp guage. Power is going to both of them. I cleaned the links and when i turn key the engine temp guage moves slightly and the pointer moves to first white line. The rev counter dosent move at all though. Going to get a multimeter monday to see whats broke and whats not.
Nite eveybody...
M
 
fucawi

fucawi

Banned
Joined
May 18, 2011
Messages
1,039
Re: Picked my brain tooo much. Totally stuck. Chrysler 75hp, early 80's. 2 stroke pro

where are you in UK ..send me a pm ..might be able to help if near by ... Bill Higham marine very expensive ......watch out
 
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