logo
Home For The Original Vintage Ski-Doo oldski-doosleds Message Board Since 2003!
Where the experts hang out. Portal for oldski-doosleds web site.
Click here for Snowmobile Events
#oldski-doosleds #vintageski-doo #vintageskidoo © 2019
Welcome, Guest. Please Login or Register.
September 20, 2019, 12:11:39 PM
Home Help Search Login Register
News: See Terms in Help Desk Area Before Using This Message Board.

  oldski-doosleds' Vintage Ski-Doo Message Board
  oldski-doosleds Message Board
  Vintage ski-doo General Disscusion

  tnt 669
� previous next �
Pages: [1] Reply Notify of replies Send the topic Print 
   Author  Topic: tnt 669  (Read 137 times)
skidoo292
Boardnation God
*****

Posts: 175



View Profile E-Mail
tnt 669
« on: September 4, 2019, 04:21:08 PM »
Reply with quote

I just acquired a 1969 TNT 669 that has been sitting a long time and is seized  Haven't got it completely apart yet but it is starting to look like the crank on the clutch side is the culprit  Does any one know if these cranks are a complete odd ball because they are a one year motor or do they share parts with any thing else?  640?  thanks
Report to moderator Logged
Doo640ER
Boardnation God
*****

Posts: 1129



President NE Ohio Leafer Madness Snowmobile Club

View Profile E-Mail
Re:tnt 669
« Reply #1 on: September 4, 2019, 05:04:27 PM »
Reply with quote

Sorry I'm no help for your question, but just wanted to say you're a lucky guy to score one of those.  Please post a few pictures if possible.
Report to moderator Logged



67 Olympique 250
70 TNT 292 (slides)
70 Olympique 12/3
70 Ski Boose MK I
72 Nordic 640ER
72 Polaris Charger 530SS
75 Olympique 300
78 Carry Boose (Black)
Chrystler Sno Runner (2)
81 Citation 4500e (2)
02 Legend GS 600
2011 GSX LE 600 E-tec
oly_man
Boardnation God
*****

Posts: 2553





View Profile E-Mail
Re:tnt 669
« Reply #2 on: September 5, 2019, 08:52:47 AM »
Reply with quote

Cool sled!  congrats!

I had a quick look at the manuals, and the 669 crank LOOKS like a newer 640 crank, but has a different number.  It appears to have one bearing on each end (PTO / MAG) which is different than the 70+ 641 cranks.  Those have two bearings on the PTO. 
What the stroke is of the 669?  Then maybe measure the bolt pattern of the cylinders & we can compare to a 640.  Might get lucky..?

Report to moderator Logged
Bones
Global Moderator
*****

Posts: 4446



Rotax Free Air Power !!!

View Profile E-Mail
Re:tnt 669
« Reply #3 on: September 5, 2019, 10:28:46 PM »
Reply with quote

Doo you want to keep it original ?? Or just wanna get er running ??  You can bolt your 669 top end onto any 640/641 bottom end.
oly_man, correct me if I am wrong here but I think only the 641 ( TNT engine) has double bearings ?? All 640 engines Nordic/Alpine etc have single bearings ??
I would have to go dust off some old books but I believe the 69 - 640 Alpine engine and the 669 engine are 100% identical in every part other than pistons and cylinders, heads are same.
The 69 - 640/669 crank is a different part number from a 70 - 640 Nordic crank as the 69 crank has the 3/4" PTO stub and the 70 has the 7/8" PTO stub.
Bones
Report to moderator Logged
oly_man
Boardnation God
*****

Posts: 2553





View Profile E-Mail
Re:tnt 669
« Reply #4 on: September 6, 2019, 05:51:14 AM »
Reply with quote

exactly Bones - 641 bottom end has two bearings.  You can see the extra bolts on the PTO side of the case:




And you are bang on as well with the cranks too.  I dug out the parts lists from 69 and compared.  The case and shaft is the same thing for a 669 and a 640.

1969
640 + 669 crank shaft - 402 1155
640 + 669 crank case - 402 0167

1970
640 crank shaft - 402 1197
640 crank case - 402 0167

So since the stroke didn't change and neither did the case, the only difference has to be the diameter of the shaft like you said.  Therefore you can pick up just about any 640 bottom end to make this 669 breathe fire again!

Report to moderator Logged
skidoo292
Boardnation God
*****

Posts: 175



View Profile E-Mail
Re:tnt 669
« Reply #5 on: September 6, 2019, 10:35:05 AM »
Reply with quote

Thank you very much.  The crank is junk for sure .Water got in the pto side and corroded the throw weights and bearings  I have a 1973 640 Nordic that I could use for a bottom end if it's the same  It has a starter gear on though.  The cylinders are good but I will need the pto side piston but there seems to be lots of them available  the machine is in very rough condition but I want to save it.
Report to moderator Logged
skidoo292
Boardnation God
*****

Posts: 175



View Profile E-Mail
Re:tnt 669
« Reply #6 on: September 6, 2019, 10:37:57 AM »
Reply with quote

I just reread your reply's  Maybe 1973 is too new?
Report to moderator Logged
oly_man
Boardnation God
*****

Posts: 2553





View Profile E-Mail
Re:tnt 669
« Reply #7 on: September 6, 2019, 12:29:25 PM »
Reply with quote

If you use the whole bottom end it will be fine.  Crankshaft number was the same from 70-72, then 73 has a new number.. but has the same stroke as the older engines.  You agree Bones?


The starter gear comes off as its just a press type fit (clutch holds it tight).  Take the clutch off and then you should be able to bring the gear out.  The last 440 I messed with came off easy...
« Last Edit: September 6, 2019, 12:32:02 PM by oly_man » Report to moderator Logged
Pages: [1] Reply Notify of replies Send the topic Print 
� previous next �
Jump to:  

oldski-doosleds' Vintage Ski-Doo Message Board
Get your Ad Free Message Board at Boardnation!   © 2013 Boardnation  Web hosting by Nubis