Author Topic: What to do while my motor is out?  (Read 845 times)

0 Members and 1 Guest are viewing this topic.

Offline GHtokyo

  • Trade Count: (0)
  • New Member
  • *
  • Posts: 2
What to do while my motor is out?
« on: March 13, 2017, 01:57:51 PM »
HI Everyone,
I revived a '68 350 GTR last year, and like an idiot, I over-torqued the exhaust flange cracking a piece off the left cylinder.   :'( So that is getting welded at the machine shop.  Besides replacing the gaskets, checking piston and ring clearances, I'm wondering if I should inspect anything on the bottom end while I have the motor out of the frame.  What are the common issues with these motors to look for?  The motor was running well, but there was some oil leaking on the left side, spraying on my left pant leg as I rode.  It looks like it was coming from the base gasket because there's lots of built up crud around there.

Greg

Offline old smokey

  • Trade Count: (0)
  • Master Registered Bridgestone Member
  • *****
  • Posts: 677
Re: What to do while my motor is out?
« Reply #1 on: March 14, 2017, 01:00:42 AM »
Hi, welcome to the Bridgestone site.
A nice starting point with that GTR there.
Did you buy that from Alex in WI?
The photo looks familiar from an ad I've seen before.
'67 350 GTR undergoing repairs with a '75 Yamaha TX500 front end

Offline Harry

  • Trade Count: (0)
  • Full Bridgestone Member
  • ***
  • Posts: 88
Re: What to do while my motor is out?
« Reply #2 on: March 18, 2017, 04:28:36 PM »
Nice looking GTR.  If you have the owners manual it would be good to read through it.  Even better is the shop manual.  This site has one that you can download.  Check it out. And welcome to the site.  With so many stoneheads it's got great info.  Harry

Offline grundlegrabber

  • Trade Count: (1)
  • Full Bridgestone Member
  • ***
  • Posts: 103
Re: What to do while my motor is out?
« Reply #3 on: March 19, 2017, 12:07:53 AM »
While the engine is out, I'd advise replacing the rubber mounts. The bottom mounts are pressed in to the frame from the top down. Engine needs to be out to remove & replace them. The rubber in the mounts deteriorates from age & oil contamination. All of the other mounts can be replaced with the engine in, but it's easier when engine is out.

Offline GHtokyo

  • Trade Count: (0)
  • New Member
  • *
  • Posts: 2
Re: What to do while my motor is out?
« Reply #4 on: March 30, 2017, 10:22:46 PM »
Thanks for all the well wishes.  Yes, Old Smokey, I bought it from Alex in Milwaukee a few years back.  I looked at the bottom motor mounts, and they are a bit deteriorated. Good Call, I should replace them, and I see Richard has those for sale also, but I wonder if there's a better option than original rubber?  I called energy suspension, no luck.  Will try Prothane next.
The welding done at Competition Cycle looks amazing, like the cylinder was never damaged!  I noticed some oil leaking from what I think is the neutral safety switch on the left side of the motor.  Looking into that now.
Greg

Offline BRT-GTR

  • Brian
  • Trade Count: (0)
  • Master Registered Bridgestone Member
  • *****
  • Posts: 608
Re: What to do while my motor is out?
« Reply #5 on: March 31, 2017, 04:58:39 PM »
       Hi Greg,
                     From experience, the neutral switch cases are notorious for developing hair line cracks which lead to an oil leak. They are made from a hard, heat set, bakelite type plastic which cracks over time or from over tightening the screws. New ones are not generally available as far as I know. Degrease the case and smear the outside with epoxy resin or similar sealant. I've just done a quick fix on one using Hylomar gasket sealant. Any other suggestions for sealing these welcome.
     Clean the contact points on the switch arm and inside the case before you put it back. Don't unscrew the switch arm unless you have to. I recently unscrewed a perfectly good one to find that the split spring lock washer turned the contact backwards, shearing off its locating lug,  dammn.
              Brian.   
« Last Edit: April 01, 2017, 05:51:00 PM by BRT-GTR »
Growing old is compulsory, Growing up is optional.

Offline ziggy stardust

  • Trade Count: (0)
  • Master Registered Bridgestone Member
  • *****
  • Posts: 666
    • Classic Japanese Restorations
Re: What to do while my motor is out?
« Reply #6 on: April 04, 2017, 05:29:01 AM »
Yes you need to encapsulate the whole switch, think I used a petrol (gas) tank epoxy type filler on mine? When fitting the three screws add some under the screw heads as well as gear box oil bleeds out through the screw holes if you don't.

Z
I am only responsible for what I say, not for how you interpret it.

Offline MitchB

  • Trade Count: (0)
  • Full Bridgestone Member
  • ***
  • Posts: 29
Re: What to do while my motor is out?
« Reply #7 on: June 04, 2017, 07:19:32 PM »
I also broke one of the exhaust flanges on my bike. I sent mine to Millennium for repair, and bit the bullet and had the bores Nikasil plated. With 300 miles since - I'm happy.
One note here - look closely at the double ended exhaust studs. If the end that goes into the cylinder / exhaust flange contacts the cylinder, it can turn and push the flange away from the cylinder and cause another break. I trimmed about 5 mm from mine to prevent this...

Definitely replace the rubber engine mounts. Some of the flanges needed the mount holes filed a bit to get all six centered properly on the bolts - other wise there can be greater tension one one side of the rubber bush which will accelerate wear.
With easier access, I replaced the oil lines as well - I used Tygon. Your local hobby shop may have the correct size.
Replaced the phillips screws on the side cases with allen heads...
Clean up / paint? I did, and it improved the looks immensely.
Sand and paint scratches on the frame?

Offline old smokey

  • Trade Count: (0)
  • Master Registered Bridgestone Member
  • *****
  • Posts: 677
Re: What to do while my motor is out?
« Reply #8 on: June 04, 2017, 08:13:32 PM »
Greg,
In early 2012 I went into a now defunct used motorcycle shop in Plymouth WI as Alex was telling the shop owner he had a GTR under a tarp that he was considering selling. I assumed the worst and figured it was outdoors under a tarp, so didn't ask for any details. I didn't really need a second GTR that needed work. Although obviously yours needs less work than mine. I hope you have it back to daily rider condition soon.
'67 350 GTR undergoing repairs with a '75 Yamaha TX500 front end

 


Gallery


Views:10
Comments (0)
By: AlanJohn

Views:8
Comments (0)
By: AlanJohn

Views:11
Comments (0)
By: AlanJohn

Views:11
Comments (0)
By: AlanJohn

Classifieds

350 GTR/GTO Dynamo Points Base Plate & Case Screws

Price: $0.00
Date: 09/14/2017 01:44 pm
Time Left: 80d 9h 12m
SUPER RARE 1965 BRIDGESTONE HUMP BACK SPORT 90.

Price: $1400.00
Date: 09/03/2017 02:02 pm
Time Left: 69d 9h 30m
Searching For Parts To Complete A 350 GTR

Date: 09/02/2017 05:19 pm
Time Left: 68d 12h 48m
Handle Bars with controls
Date: 08/17/2017 04:27 pm
Time Left: 52d 11h 55m

Recent Downloads added

How to build a 149 mph 350GTR....
Rating: (None)
Filesize: 7154.56KB
Date: April 18, 2017, 08:25:38 AM
Bridgestone 100 Sport Brochure
Rating: *****
Filesize: 937.72KB
Date: July 08, 2015, 12:58:53 PM
BS 100 Sport Australian Brochure
Rating: *****
Filesize: 937.53KB
Date: June 29, 2015, 06:40:40 PM
Bridgestone 350 GTO - Moto L├ęgende May 2003
Rating: *****
Filesize: 9429.41KB
Date: April 22, 2015, 04:18:43 PM

Powered by EzPortal