Author Topic: Running Hot .  (Read 1235 times)

0 Members and 1 Guest are viewing this topic.

Offline Iain Cameron

  • Legend
  • *****
  • Posts: 1963
    • View Profile
Running Hot .
« on: September 10, 2018, 06:06:41 PM »
Guys Im stumped . Ive got the old Yamaha DT1 running for the Nats full rebuild all new parts ( gaskets , seals , ect ) .
She is running very Hot and Im at a loss as to why . Carb has been cleaned and the same jets replaced . no air leaks tested with pressure and spraying start ya bastard over all areas . runs crisp great response .
Could the timing be to advanced ? .
all ideas welcome . Iain .
Yamaha tragic ; dt1, rt1, dt2, rt2, dt2mx , rt2mx , mx250, mx360,sc500, 74dt125, yzx125, yzc250, yzc400, yzd250, yzd400, yzh250, yzh80 , dt100 , xr75 ko xr80 03 , it175 82 . Not a member of any club

Offline Momus

  • Legend
  • *****
  • Posts: 520
    • View Profile
Re: Running Hot .
« Reply #1 on: September 10, 2018, 07:04:28 PM »
What ignition system do you have Iain?

Offline 80-85 husky

  • Legend
  • *****
  • Posts: 3740
    • View Profile
Re: Running Hot .
« Reply #2 on: September 10, 2018, 07:43:35 PM »
try lifting the needle clip to richen her up a tad

Offline Iain Cameron

  • Legend
  • *****
  • Posts: 1963
    • View Profile
Re: Running Hot .
« Reply #3 on: September 10, 2018, 09:32:08 PM »
Ive lifted the clip 80-85 husky . Im running a DT400 cdi system Momus . the same system that was in her b4 the rebuild .
Yamaha tragic ; dt1, rt1, dt2, rt2, dt2mx , rt2mx , mx250, mx360,sc500, 74dt125, yzx125, yzc250, yzc400, yzd250, yzd400, yzh250, yzh80 , dt100 , xr75 ko xr80 03 , it175 82 . Not a member of any club

Offline ralph311

  • C-Grade
  • **
  • Posts: 53
    • View Profile
Re: Running Hot .
« Reply #4 on: September 11, 2018, 11:03:35 AM »
What are you seeing that indicates it's running too hot?

Could the compression be too high? (maybe the new head/base gaskets are thinner than the old ones??)

Offline Suzukal

  • C-Grade
  • **
  • Posts: 71
    • View Profile
Re: Running Hot .
« Reply #5 on: September 11, 2018, 11:14:33 AM »
You may want to lower the needle clip to richen it up not raise it.

Offline 80-85 husky

  • Legend
  • *****
  • Posts: 3740
    • View Profile
Re: Running Hot .
« Reply #6 on: September 11, 2018, 02:07:30 PM »
your right...i meant to say lift the needle...not clip! :o

Offline Momus

  • Legend
  • *****
  • Posts: 520
    • View Profile
Re: Running Hot .
« Reply #7 on: September 11, 2018, 03:27:37 PM »
Ive lifted the clip 80-85 husky . Im running a DT400 cdi system Momus . the same system that was in her b4 the rebuild .

Ok. Perhaps put a timing light on it and check not advanced or if the header is hot, retarded. I have had some recent fun and games with early Yamaha CDI.

Offline Iain Cameron

  • Legend
  • *****
  • Posts: 1963
    • View Profile
Re: Running Hot .
« Reply #8 on: September 11, 2018, 10:16:21 PM »
Ralph the smell of burning alloy after 15 to 20 min runs better with the choke on . Might try a Cpl of extra head gaskets . Momus good idea will try the light .
Yamaha tragic ; dt1, rt1, dt2, rt2, dt2mx , rt2mx , mx250, mx360,sc500, 74dt125, yzx125, yzc250, yzc400, yzd250, yzd400, yzh250, yzh80 , dt100 , xr75 ko xr80 03 , it175 82 . Not a member of any club

Offline Iain Cameron

  • Legend
  • *****
  • Posts: 1963
    • View Profile
Re: Running Hot .
« Reply #9 on: September 11, 2018, 10:18:04 PM »
I got it arse about to . Ive raised the needle not the clip .
Yamaha tragic ; dt1, rt1, dt2, rt2, dt2mx , rt2mx , mx250, mx360,sc500, 74dt125, yzx125, yzc250, yzc400, yzd250, yzd400, yzh250, yzh80 , dt100 , xr75 ko xr80 03 , it175 82 . Not a member of any club

Offline 80-85 husky

  • Legend
  • *****
  • Posts: 3740
    • View Profile
Re: Running Hot .
« Reply #10 on: September 12, 2018, 09:07:54 AM »
how is it running? crisp? lean? blubbery? got the right heat range plug ...sorry just randomly firing stuff out.. ::)

Offline TT5 Matt

  • Legend
  • *****
  • Posts: 1431
    • View Profile
Re: Running Hot .
« Reply #11 on: September 12, 2018, 01:08:12 PM »
if it was running ok before why not put the old parts back in the carb and see if it cures it,tried doing plug chops to see whever its lean/rich or just right

Offline ralph311

  • C-Grade
  • **
  • Posts: 53
    • View Profile
Re: Running Hot .
« Reply #12 on: September 12, 2018, 01:45:35 PM »
If it runs better with the choke on its definitely much too lean for some reason. That'll make it run hot. Fix the lean running and see what you think.

Offline 80-85 husky

  • Legend
  • *****
  • Posts: 3740
    • View Profile
Re: Running Hot .
« Reply #13 on: September 12, 2018, 05:55:32 PM »
ol mate had a very hot 440 at harrow and he dropped the needle 2 slots and it was perfect after that... but i get the hot bit... it was so hot it was ticking and you could feel the heat radiating from the motor for a metre away...must have been v close to a lock up. the plug was too hot to handle for 5 mins....

Offline Iain Cameron

  • Legend
  • *****
  • Posts: 1963
    • View Profile
Re: Running Hot .
« Reply #14 on: September 15, 2018, 03:35:54 PM »
Well I now have a year to solve the problem . My falcon ute blew its gearbox on Thursday cant get one in time to swap over and still catch the boat over to vic to make the nats . tried rebooking no spaces left on the boat .
Yamaha tragic ; dt1, rt1, dt2, rt2, dt2mx , rt2mx , mx250, mx360,sc500, 74dt125, yzx125, yzc250, yzc400, yzd250, yzd400, yzh250, yzh80 , dt100 , xr75 ko xr80 03 , it175 82 . Not a member of any club

Offline Momus

  • Legend
  • *****
  • Posts: 520
    • View Profile
Re: Running Hot .
« Reply #15 on: September 15, 2018, 06:32:51 PM »
Well I now have a year to solve the problem . My falcon ute blew its gearbox on Thursday cant get one in time to swap over and still catch the boat over to vic to make the nats . tried rebooking no spaces left on the boat .
Shit no good. What about renting a vehicle?

Offline Iain Cameron

  • Legend
  • *****
  • Posts: 1963
    • View Profile
Re: Running Hot .
« Reply #16 on: September 15, 2018, 09:29:45 PM »
I cant with knowing I have a huge bill go on holiday as a self employed person with out any money coming in . tried rebooking the spirit but no spaces left to get me over in time . usually need to book weeks in advance the trouble living on an Island .
Yamaha tragic ; dt1, rt1, dt2, rt2, dt2mx , rt2mx , mx250, mx360,sc500, 74dt125, yzx125, yzc250, yzc400, yzd250, yzd400, yzh250, yzh80 , dt100 , xr75 ko xr80 03 , it175 82 . Not a member of any club

Offline GMC

  • Legend
  • *****
  • Posts: 3624
  • Broadford, Vic
    • View Profile
Re: Running Hot .
« Reply #17 on: September 16, 2018, 09:08:59 PM »
Bummer, it sucks when plans go south and the years slip by
G.M.C.  Bringing the past into the future

Shock horror, its here at last...
www.geoffmorrisconcepts.com

For the latest in GMC news...
http://www.geoffmorrisconcepts.com/8/news/

Offline skypig

  • Legend
  • *****
  • Posts: 532
    • View Profile
Re: Running Hot .
« Reply #18 on: September 17, 2018, 09:47:08 AM »
Bummer, it sucks when plans go south and the years slip by

Yes.
I just wasted over $600 on entry fees for an Historic Road Race meeting. (Plus bike prep, annual leave... etc)
I set up on Friday, (week ago) then spent 36hrs in bed. I haven’t been that sick for a while.

I’ll try next year.

Offline Lozza

  • Legend
  • *****
  • Posts: 4199
    • View Profile
Re: Running Hot .
« Reply #19 on: September 17, 2018, 10:26:47 AM »
That sucks Iain, if the engine is over heating (a cheap laser temp gun makes diagnosis easier) and the jetting doesn't go blubbering rich at the same time you must be very lean to begin with. Jetting will get richer with heat.
Jesus only loves two strokes

Offline Iain Cameron

  • Legend
  • *****
  • Posts: 1963
    • View Profile
Re: Running Hot .
« Reply #20 on: September 17, 2018, 10:51:05 PM »
Lozza Ive got time now , going to pull her apart and start with the carb one jet at a time . Im sure I put the same sizes back as I took out . But stranger things have happened . will but a heat gun and see . Planning on a full rebuild again but adding one new bit from std each time to see were I went wrong . eg std head the GYT head test with both . on and on till I find the problem . Skypig that's a bummer hope your better now .
I will post the answers when I find them .
Yamaha tragic ; dt1, rt1, dt2, rt2, dt2mx , rt2mx , mx250, mx360,sc500, 74dt125, yzx125, yzc250, yzc400, yzd250, yzd400, yzh250, yzh80 , dt100 , xr75 ko xr80 03 , it175 82 . Not a member of any club

Offline skypig

  • Legend
  • *****
  • Posts: 532
    • View Profile
Re: Running Hot .
« Reply #21 on: September 18, 2018, 09:24:36 AM »
I will be interesting to find the issue. Good luck.

I’m 99% recovered. Thanks.