facebook1 youtube1 twitter1 instagram google plus linkedin1 pinterest1

logosmallNOTICE:  If you are not a free registered member of the site, you will not see the photos in the forum, and you won't be able to access our premium member content. Please consider joining our community!

Welcome, Guest
Username: Password: Remember me
13 Jul 2018
I have re-enabled Tapatalk and will try to keep it functional assuming they keep the plug in updated. You can get the mobile app at: www.tapatalk.com/tapatalk_mobile
  • Page:
  • 1

TOPIC: Rebuilding my blown TF100/125 bucket racing motor from 20 years ago.

Rebuilding my blown TF100/125 bucket racing motor from 20 years ago. 15 Apr 2018 02:50 #1

  • RT325
  • RT325's Avatar Topic Author
  • Offline
  • Collector
  • Collector
  • Posts: 3131
  • Likes received: 900
Had a monumental blow up 20 years ago while comfortably leading the 30 lapper at the local airforce base & was lucky to walk away from it. Not sure what broke first--the piston skirt or the cylinder as porting didn't leave much metal for the cylinder overhang--to hang on looking at it now. Built up another motor after that using a short stroke yamaha crank but although it ran good it was just another one of my cock ups as needed to sort the porting to match the stroke & overbore it a bit. So decided to leave that motor mostly together as it runs ok & start again. Apart from a bent rod everything else down the bottom survived & has high speed mains with fiber cages. Jeez we though we were fast using those lol. So have it together except for top end, even found a complete cdi mag but might go to the small rotor off the other one in the end. I'll put a few pics up of my cheapy methods with very limited gear & a box full of old bits. & i know one pic shows rust on the crank wheels. Ok then i'll clean it off!!. By the way, i got it trued up to almost zero both sides after it wasn't looking good for a while. My big copper hammer fell to bits & small one was useless. I just hold the crank by hand & belt the other half. Gave up & drove it hard into alloy on the concrete & crept it around. Bit of chisel to spread it & bit of vice squeezing as overdid it, not spreading at the pin but just flexing the wheels chasing my high spot chalk marks all around. Width is 56mm but of course one more click in the press & 55.9 so reversed it & 56.1 so ended up pressing & hitting the press frame near the flywheel & crept it down to 56 width. Hate doing that & hate truing them up too. Thread on the mag end is often not true centered after 35 years of people belting it so always put that end in the tailstock chuck just up to the keyway. Had a brass chuck at work which was good for that. Other end i just lock a center in the three jaw chuck as that end never gets bent. Motor went together good using some old gasket goo stuff in a tub & same with clutch cover, [they don't run a center gasket anyway]. They say pics are worth a thousand words so thought i'd better 'try & explain' my rough 'as' methods.

Please Log in or Create an account to join the conversation.

Rebuilding my blown TF100/125 bucket racing motor from 20 years ago. 15 Apr 2018 02:54 #2

  • RT325
  • RT325's Avatar Topic Author
  • Offline
  • Collector
  • Collector
  • Posts: 3131
  • Likes received: 900

Please Log in or Create an account to join the conversation.

Rebuilding my blown TF100/125 bucket racing motor from 20 years ago. 15 Apr 2018 02:57 #3

  • RT325
  • RT325's Avatar Topic Author
  • Offline
  • Collector
  • Collector
  • Posts: 3131
  • Likes received: 900

more pics
Attachments:
The following user(s) Liked this Post: MarkT

Please Log in or Create an account to join the conversation.

Last Edit: by RT325.

Rebuilding my blown TF100/125 bucket racing motor from 20 years ago. 15 Apr 2018 07:55 #4

  • MarkT
  • MarkT's Avatar
  • Offline
  • Site Contributor
  • Site Contributor
  • Posts: 4002
  • Likes received: 1774
Are you sure it didn't just "run out of gas"? That's what the factory race teams always said back in the 1970's when one of the team bikes broke down... reason for not finishing? "Ran out of gas"

(Now of course what REALLY happened to the factory team bike was something like the piston let go and part of the rod broke through the head and punched a hole in the gas tank... therefore reason for DNF??? "ran out of gas" :haha )

Seriously... thanks for posting. Always love to see your projects and methods!

Please Log in or Create an account to join the conversation.

1963 YG1-T, 1965 MG1-T, Allstate 250, 1970 CT1b, 1971 R5, 1973 AT3MX, 1974 TS400L, 1975 RD350, 1976 DT175C, 1976 Husqvarna 250CR, 1981 DT175G, 1988 DT50, 1990 "Super" DT50, 1991 RT180, 2017 XT250
  • Page:
  • 1
Moderators: DEETDevinDmanEnduronutMakotosunVinnieyamadminJames Hart
Powered by Kunena Forum