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  1. M

    ‘90 300gt V8 surging and smoking

    Update -have a water tank to run it at home -disconnected oil tank and now have premix 50:1 in main tank -replaced head gaskets, no change. - let all water drain out. Started it for a few seconds, let it cool, did that several times. Still smoking with NO water flowing in it anywhere. - has to...
  2. M

    1990 Johnson 300hp GT V8 smoking

    I don’t doubt it’s not hard to do, but what am I looking for when I get there. Will damage be obvious? Thank you!!!
  3. M

    1990 Johnson 300hp GT V8 smoking

    thanks for the info! But if the VRO is bad, as suspected, I need to replace no matter price. if I do both I’m up to 1000. Still a LOT less than buying another boat. And I can’t sell this one not running right. Can’t tell you how much I appreciate your advice and info. Thank you!!!
  4. M

    1990 Johnson 300hp GT V8 smoking

    BTW, I just finished the restoration this spring. Gelcoat, all new upholstery, lighting, gages…electronics. I’m 65 and not planning to ever buy another boat so I don’t mind putting some money in this one. Still better than going out and spending $50-$75k for a new one!!!
  5. M

    1990 Johnson 300hp GT V8 smoking

    I can replace both VRO’s for about $350. It’s a 1990, so I’m probably going to be doing it at some point anyhow. What’s your thought on just go ahead and replace them? I can also get the complete gasket kit for about $100. So for less than $500, I have all good gaskets, new VRO’s, good...
  6. M

    1990 Johnson 300hp GT V8 smoking

    here’s what I know… Smoking white smoke (not steam) Compression 116-118 all cylinders Getting worse All plugs and piston tops look the same Last night would barely get on plane. Almost like running on 4 cylinders Idles rough, with a “PUH” every few seconds Lots of smoke when starting Has 2...
  7. M

    ‘90 300gt V8 surging and smoking

    Should I go ahead and add oil to the gas while I’m figuring it out?
  8. M

    ‘90 300gt V8 surging and smoking

    Please excuse my ignorance, I know I’m in way over my head on this one… It has 2 VRO’s. Doesn’t each one feed the 4 cylinders on one side? Would one side of plugs/pistons/ or something show signs of a difference?
  9. M

    ‘90 300gt V8 surging and smoking

    Update, very little water in gas. Added Heet to help. Pulled plugs again, top of all pistons look good, all the same. Compression on all 8 cylinders is between 116-119. No leakage of pressure. I think I’m ruling out head gasket. . I need to run it at the lake next to see if clamp on oil primer...
  10. M

    ‘90 300gt V8 surging and smoking

    Got to work on it a little last night. Pulled all the plugs and they looked good. Checked oil tank and found a broken clamp on engine side of the primer bulb. No other leaks found on the engine. Oil tank was very low ( not sure why alarm hadn’t gone off). Emptied it and there was some water in...
  11. M

    ‘90 300gt V8 surging and smoking

    Thanks all!! Waiting for the weekend to check things. And still trying to decide if I’m brave enough to sit on the back of the boat with my wife driving😳
  12. M

    ‘90 300gt V8 surging and smoking

    Sorry, I figured by ur response u would know, didn’t know if others reading would Thanks!
  13. M

    ‘90 300gt V8 surging and smoking

    yes, still VRO
  14. M

    ‘90 300gt V8 surging and smoking

    Hi, it’s a 2 cycle. I’ll try to find the red lever, I have the manual for it. I don’t have a portable tank. Bulb (fuel) is hard, I’ll check oil bulb. Will also check fuel filter. Thanks!
  15. M

    ‘90 300gt V8 surging and smoking

    Just started doing this. Compression good on all 8. Good impeller. Plugs changed last fall. Tried sea foam. Speeds up and slows both on idle and plane. Smokes a lot when started and when running in “bog” mode if that makes sense. Harder to start than normal. Used to start on 1st key turn once...
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