Author Topic: SP370-DR400 cam interchangeability  (Read 3092 times)

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Offline JC

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SP370-DR400 cam interchangeability
« on: July 17, 2008, 12:23:49 pm »
Can anyone tell me if the cams are interchangeable on the 370 & 400 SP/DR's of late 70's-early 80's?

oldfart

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Re: SP370-DR400 cam interchangeability
« Reply #1 on: July 17, 2008, 02:36:49 pm »
Kawboy
           Best to use the DR 400 top end as they are a straight bolt on .
Make sure you  have cleaned out the oil gallery & buy a new oil filter as they have a bad habbit of chewing out the head cam bearings.
370 motor also accepts the 400 barrel -head n topend  ;)

Offline JC

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Re: SP370-DR400 cam interchangeability
« Reply #2 on: July 17, 2008, 02:39:29 pm »
Thanks Oldy,

So the cams are not interchangeable?

Tony T

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Re: SP370-DR400 cam interchangeability
« Reply #3 on: July 17, 2008, 02:53:03 pm »
I've got tonnes of SP/DR370 parts to get rid of................  ;)

oldfart

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Re: SP370-DR400 cam interchangeability
« Reply #4 on: July 17, 2008, 03:00:54 pm »
Tony what's the heads like at the cam bearings ???

Tony T

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Re: SP370-DR400 cam interchangeability
« Reply #5 on: July 17, 2008, 07:07:38 pm »
From memory, I think they're ok, Stewy. But when I'm home on Saturday, I'll check it out.
that stuff will go seriously cheap. Demand for SP370's isn't that great.

Yeah, I know........... I can't believe it either................  :D

Offline Freakshow

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Re: SP370-DR400 cam interchangeability
« Reply #6 on: July 18, 2008, 12:12:43 am »
that motor has never travelled further in its life than it has in the last 3 months............. hehee
74 Yamaha YZ's - 75 Yamaha YZ's
74 Yamaha  flattracker's
70  Jawa 2 valve speedway's

For sale -  PRE 75 Yamaha MX stuff, frame, motors and parts also some YAM DT1,2,A and Suzi TS bikes and stuff

oldfart

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Re: SP370-DR400 cam interchangeability
« Reply #7 on: July 18, 2008, 03:32:25 pm »
Tony if the heads and rocker gear  are OK- I'll take one or more  IF Kawa doesn't want em .

Believe or not the I can get the SP 370 to rev harder than the DR  400  ::)

Tony T

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Re: SP370-DR400 cam interchangeability
« Reply #8 on: July 18, 2008, 05:36:01 pm »
I'll check out what there over the weekend.
There's lots of motor bits I reckon.

Offline cloggy

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Re: SP370-DR400 cam interchangeability
« Reply #9 on: October 20, 2008, 05:39:02 am »
370 carb has points on end, 400 doesn't.
I think the reason for the 370 revving better is the carb. I used to think it was the ignition [400 has black box advance] but since using a 370 carb .....

oldfart

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Re: SP370-DR400 cam interchangeability
« Reply #10 on: October 20, 2008, 04:01:27 pm »
Both running the same carb ( and jets )    I would tend to agree it's in the points setting .
The 370 just rev harder .

Offline cloggy

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Re: SP370-DR400 cam interchangeability
« Reply #11 on: October 20, 2008, 06:40:03 pm »
I have had a vast improvement with the earlier carb but other than that no comparison so thanks. When they came out the sp was a fair bit faster through the speed trap

Offline cloggy

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Re: SP370-DR400 cam interchangeability
« Reply #12 on: October 20, 2008, 06:46:43 pm »
Further to that back in the 80s a friendly electronics mate said the black box was dead crude and just came on full advance about 3 to 3.5 thousand revs. That being so a modern more sophisticated device might have more tuning effect than anything else!