« previous next »
Pages: [1]   Go Down

Author Topic: Overheating?????  (Read 2258 times)

0 Members and 1 Guest are viewing this topic.

Offline SGTBob

  • SGT Bob
  • Full Member
  • *
  • Posts: 47
  • Who woulda guessed????
Overheating?????
« on: August 29, 2012, 05:20:37 PM »
OK, I've read about using 10W-40 oil,  and that Yamahlube is the best oil to use. However, I feel as though there is more going on than just "Oil" can solve.
My CB750A runs hot.  By that I mean over 230 degrees F after about 50-70 miles.  The heads are at about 190 degrees while the block and lowers are running at over 230 degrees.
Will changing the oil be the solution or should I consider a complete tune-up?
I feel as though the timing might be a contributing factor, or even the dwell or point setting.
What would the other member suggest?  Could there be an oil flow problem??  God, I hope not!!!!
Logged
Current Rides:
Vstrom DL650 Adventure (New)
'77 CB750A

Offline raymond10078

  • Moderator
  • Expert
  • *****
  • Posts: 775
  • Just learnin' as I go . . . .
Re: Overheating?????
« Reply #1 on: August 29, 2012, 06:50:05 PM »
Your temps don't sound that hot to me.  I did some searching on this site - and 230 seems to be in the OK range:

http://forums.sohc4.net/index.php?topic=72692.0

http://forums.sohc4.net/index.php?topic=105060.0

Granted - if you think your bike is timed wrong, etc - then get it fixed!  Gapping the points accurately will get you "in the ball park" as far as dwell goes, and just as making sure your static timing is correct (with just a light bulb, or an ohmmeter) will do as well.

Lastly, give your plugs a read and make sure you're not running lean on one/more cylinders.
« Last Edit: August 29, 2012, 06:53:18 PM by kandrtech »
Logged
1978 CB750A (upgrading very, very slowly)

Past bikes - Honda: SL350, CX650C, CB900C, CB1000C, CM450A; Kawasaki: several 1972 750 H2's; Suzuki: TC90J.

Bikes I want: CX650ED, a mid-sized japanese V-twin with ABS.

Offline SGTBob

  • SGT Bob
  • Full Member
  • *
  • Posts: 47
  • Who woulda guessed????
Re: Overheating?????
« Reply #2 on: August 30, 2012, 05:35:31 PM »
Well, I've checked and double checked the plugs.  And yes, when I get time I will look into the points, condencers, dwell, etc.   :-\
I've looked at the oil and it looks very clean, but I have no idea what type or viscosity of oil the previous owner put in the bike.   :o
I guess I was "thinking" it was running a bit warm, since all I've ridden (over the past 4-5 years) has been water cooled bikes, so I'm a little out of touch with air cooled bikes.  As a matter of fact, I can't even remember when I last road an air cooled bike, except the CB750A.   ;)
Thanks for the input.  That is exactly what I was looking for.
 :) :) :) :) :) :) :) :) :) :) :) :) :)
Logged
Current Rides:
Vstrom DL650 Adventure (New)
'77 CB750A

Offline salukispeed

  • Enthusiast
  • **
  • Posts: 159
Re: Overheating?????
« Reply #3 on: September 05, 2012, 09:29:04 AM »
Your temps seem fine. My 84 goldwing gets up over 210 deg on a regular basis. My 74 CB 750 K4 was over 250 if stuck in traffic and never was an issue. But it is like sitting over a barbecue grill.
Logged
1974 CB750 K4
1970 CT70
1966 CA77 (305 Dream)
1984 GL1200 Interstate
1977 750A
1972 CL100
Pages: [1]   Go Up
« previous next »