2 STROKE WORLD .net

The 2-Stroke Garage => Turning Wrenches => Topic started by: 1976RD400C on July 29, 2022, 08:37:27 AM

Title: Rebuilding an old Ebay crank
Post by: 1976RD400C on July 29, 2022, 08:37:27 AM
Maybe next time let go of the throttle when it starts knocking  :umm:

(https://i.ibb.co/hXnsCjN/rod1.jpg) (https://ibb.co/s5DjtG4)
(https://i.ibb.co/pd7xyrZ/rod2.jpg) (https://ibb.co/RcF9y4P)
Title: Re: Rebuilding an old Ebay crank
Post by: The Red Scourge on July 29, 2022, 09:40:17 AM
 :jaw:
Title: Re: Rebuilding an old Ebay crank
Post by: m in sc on July 29, 2022, 09:57:45 AM
man it happens quick sometimes. holy cow.

that needs to be a lamp base.
Title: Re: Rebuilding an old Ebay crank
Post by: pidjones on July 29, 2022, 12:41:38 PM
Won't buff out.
Title: Re: Rebuilding an old Ebay crank
Post by: Clem710 on July 29, 2022, 01:40:17 PM
Hey, didnt punch a whole through anything :smiley:
Title: Re: Rebuilding an old Ebay crank
Post by: Kawtriplefreak on July 29, 2022, 03:07:52 PM
A couple of good licks with the swing press and a new bearing and it will be good to go. Heat it up cherry red 1st.... :olaf: :olaf:
Title: Re: Rebuilding an old Ebay crank
Post by: teazer on July 29, 2022, 03:35:35 PM
That will buff out.  No worries M8.

Not the worst I have seen.  A have a very special three piece TZ con rod here that's a nice companion for the two piece valves from one of our CB160 racers that the rider thought was OK to ride round half of Road America.  That one came with a special lightweight ventilated piston crown. 

TZ rod had a slight bend from a leaky fuel tap and roller starter combo and as it rubbed on the flywheel it reached failure temps pretty quickly before it broke out for fresh air.  The giveaway was the pile of roller bearings in the fairing belly pan.  :whistle:
Title: Re: Rebuilding an old Ebay crank
Post by: 1976RD400C on July 29, 2022, 05:50:16 PM
Close up  :eek:

(https://i.ibb.co/3CP9MVn/rod3.jpg) (https://ibb.co/YLVFyJx)
Title: Re: Rebuilding an old Ebay crank
Post by: m in sc on July 29, 2022, 06:10:44 PM
jb weld and a dremel. and, as timmy said, few whacks w the ol swing press. like newski  :righteous:
Title: Re: Rebuilding an old Ebay crank
Post by: old-man on February 08, 2023, 05:56:07 PM
I do not know how to start a new topic.  So, I also bought a RD400C crank on ebay. It came from a low-use engine. I checked the rod bearing play side-to-side. There is no up and down play and checked crank shraightness, replaced the outside bearings and got new seals. After putting engine in the frame, I then noticed that one rod has a pink area on one side at the crank bearing.
Is this bad? I took pics of the other side and other rod. see pics
Title: Re: Rebuilding an old Ebay crank
Post by: Striker1423 on February 08, 2023, 09:46:40 PM
It got hot lol
Title: Re: Rebuilding an old Ebay crank
Post by: irk_miller on February 09, 2023, 05:55:10 AM
Steel turns blue at 520°F and purple at 575°F. It becomes incandescent above 800°F.