Author Topic: Running Hot .  (Read 1220 times)

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Offline Iain Cameron

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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

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Re: Running Hot .
« Reply #1 on: September 10, 2018, 07:04:28 PM »
What ignition system do you have Iain?

Offline 80-85 husky

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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