Results 1 to 8 of 8

Thread: NEED HELP

  1. #1

    Join Date
    Jun 2011
    Location
    Tallahassee , Fl
    Posts
    9

    NEED HELP

    Overheating Yamaha

    1998 Yamaha XL1200 . Run at 3000to 5000 rpms for a mile or so and it will overheat. Run WFO wont overheat.Things I have already done. Checked temp sensor pops at 200 degrees F and opens at 184 degrees F tested 3 times 3 diff temp guages. Pulled exhaust <all>checked all passages / pulled exhaust manifold and checked. pulled head and checked cylenders and passages. All exhaust gaskets replaced and head gasket. Pull and visually inspected all cooling hoses nothing found pulled and replaced impeller with sbt rebuild .Checked pump hole and thru hull fitting nothing. Checked pink CDI box wire and has no continuity. Checked function of meter and pops with solid ground. Cant get it to overheat with flush even with very low flow .. Been back and forth to lake testing many times any help would be great.. Tired of lugging it back and forth.lol


  2. #2

    Join Date
    Jan 2006
    Location
    Texas City, Texas
    Posts
    1,249
    +1
    15
    So is it actually running hot between 3k to 5k, or is the temp. sensor lieing to you?

    Can you not find a spot to test the water temp that is running through your exhaust system to find out if it is getting hot. Fishermen use a cheap water temp unit that helps them to locate fish at various depths based on water temp. I tapped a 3/8 fitting into my head on my GPR and dump water overboard to help heat up my exhaust system. I've measured the temp of the engine by using this sensor. I just taped it to the fitting mounted in the hull. Engine temp ran between 110 and 140 degrees F depending on RPM's. It ran colder in the winter. This helped me to find out where my water temps were operating.

    I got the unit at Academy sports store for about 15 bucks.

  3. #3
    Yamaha artisan Cutlass's Avatar
    Join Date
    Oct 2010
    Location
    Madison, WI, USA
    Posts
    2,500
    +1
    55
    this is the old 65U, non power valve motor correct? Any modifications we should know about? So far, you've tried about everything I can think of. I like salty's idea of actually measuring the water temp to see if its actually overheating

  4. #4

    Join Date
    Jun 2011
    Location
    Tallahassee , Fl
    Posts
    9

    Overheating

    Only thing that has been done is the oil pump removed and look as if head has been replaces due to it being black and the rest of engine is metalic gray.Pre -mix ams oil at 50 to 1.Ill try to install a temp wire in the water flow at the lower exhaust pisser at big hose clampand Try to test tomarrow and shoot exhaust pipe with a mastertec heat gun and see how hot it is getting out on the water .Any other thoughts would be of great help. Thanks for your responce.

  5. #5
    Yamaha artisan Cutlass's Avatar
    Join Date
    Oct 2010
    Location
    Madison, WI, USA
    Posts
    2,500
    +1
    55
    I bought a head off an '98 XL1200 and it was black also. Maybe they came like that.

  6. #6

    Join Date
    Jun 2011
    Location
    Tallahassee , Fl
    Posts
    9
    OK .Alot has been going on but this F--en thing is killing me..replaced temp sensor . Cdi swapped from good running one . Inline temp shows 135 degrees when limp mode starts<the water out at top of exhaust pipe .>Raytech heat gun show appoxs same reading but bench tests good with new senor also..Water flow out of pisser is great and feels like hot bath water can even touch the exhaust for a short period so its not like its getting to 200 degrees. Thought cdi was popping rev limiter to soon but swapped that out . damm this thing.. lol..Been thru carbs and all i found was the ilde jet for #2 carb was in wrong carb..set at factory specs . Could the display have anything to do with this? Like on some polaris.Never heard of yamahas having those issues.What havent I done . Short of dynomite.

  7. #7
    Yamaha artisan Cutlass's Avatar
    Join Date
    Oct 2010
    Location
    Madison, WI, USA
    Posts
    2,500
    +1
    55
    Thats a tough one! Have you completely disassembled this exhaust pipe and checked all the cooling jackets/passages? This is where the temp sensor mounts and also where sand/rocks like to pack in and clog up


  8. #8

    Join Date
    Jan 2006
    Location
    Texas City, Texas
    Posts
    1,249
    +1
    15
    You still have not told us what evidence convinces you that it is overheating. Is the piping way hot, can you not touch the engine after a run without burning some fingers? Does water sizzle if it hits your engine? Yamaha's are not known for having overheating issues.

    Exactly what is your engine doing? That 65U is a tough old bird, but even they can only handle so many episodes of over heating before they let go.

    An experience with my 97 GP with the 65U was that it began to cut out in the mid range. This happened ONLY AFTER the engine warmed up. An old tuner from Kentucky told me that the plug wires go bad at the connections between the plug wire and plug boots. I was instructed to pull the boots, cut 3/8 inch off the wires and reinstall the boots. He told me that the wires breakdown internally and begin to arc, but they get to a point where they have broken down so badly, they cannot jump the break because the wires get hot (when the engine warms up) and the resistance increases. The plug cannot get spark and the engine dies........

    I'm not saying that this is your problem, but I AM saying that it is a problem with the 65U spark plug wires. If your symptoms are anything like I am describing, perhaps you should consider this.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. new 05 RXT NEED HELP
    By RXPNJ in forum 4-Tec Performance
    Replies: 12
    Last Post: 07-03-2009, 12:16 PM
  2. NEED HELP URGENT(HULK) RXP DOWN
    By macattack in forum 4-Tec Performance
    Replies: 28
    Last Post: 11-22-2005, 02:39 PM
  3. My 2 RXP's need HELP!
    By Tube Master in forum 4-Tec Performance
    Replies: 21
    Last Post: 07-19-2005, 09:44 PM
  4. I need help remove stock intercooler
    By orc in forum 4-Tec Performance
    Replies: 3
    Last Post: 05-13-2005, 04:08 PM
  5. NEED HELP!!!!!
    By MartyRXP in forum 4-Tec Performance
    Replies: 11
    Last Post: 05-10-2005, 08:15 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •