Author Topic: Gtr oil feed  (Read 1084 times)

0 Members and 1 Guest are viewing this topic.

Offline AlanJohn

  • Trade Count: (0)
  • Full Bridgestone Member
  • ***
  • Posts: 216
Gtr oil feed
« on: December 24, 2018, 07:43:29 AM »
I'm looking for some advise please.
I've replaced the oil lines on one of my Gtrs and the left hand side feed to the motor keeps getting air locked,if l hold the pump open on tickover l can watch the oil pump up to the union (which isn't blocked)l took it off run the engine and watched it pump oil through, but whatever l do it loses about an inch of oil from the pipe within aprox l hour and overnight about half the pipe is empty.
Is this normal the oils not leaking out l can't understand it.
I've got 20/1 in the fuel as l've rebuilt the top end and the last thing l'm going to do sieze it up.
I've a few of these bikes and the rest have oil in the pipes all the time.
Thanks in advance.
Alan.
« Last Edit: December 24, 2018, 01:24:42 PM by AlanJohn »

Offline OldSwartout

  • Global Moderator
  • Trade Count: (0)
  • *******
  • Posts: 1314
Re: Gtr oil feed
« Reply #1 on: December 25, 2018, 05:39:31 PM »
If there doesn't seem to be a leak indicated by oil collecting around the line across the engine, the check valve or in the carburetor cavity, then it has to be going into the engine through the check valve.  That can't happen if the check valve is operating correctly.  Does the left side smoke excessively after it starts? 

Karl Swartout
Mooresville, IN
BS175 Roadracer. BS200RS, BS350 GTR

Offline AlanJohn

  • Trade Count: (0)
  • Full Bridgestone Member
  • ***
  • Posts: 216
Re: Gtr oil feed
« Reply #2 on: December 26, 2018, 04:06:12 AM »
No it doesn't it actually seems to smoke less than the left side ,when the revs are increased you can see movement of oil at the union,as you say it must be going somewhere.or not having enough pressure to pump up past the union.
The right side smokes more as there is oil in the fuel as well and it's getting fed from the pump and the fuel l've got a feeling that the left isn't getting it from the pump but only the fuel.
Do the pumps get weak and become not strong enough to do the longer run to the left side?
Or do they either work or not with no imtermediate faults?
Is there a correct way to fit the unions to the engine.is it the hollow well type resorvore facing upwards or downwards there obviously made that way for a reason maybe l've got them upside down.(hopefully )
« Last Edit: December 26, 2018, 08:58:41 AM by AlanJohn »

Offline BRT-GTR

  • Brian
  • Trade Count: (0)
  • Master Registered Bridgestone Member
  • *****
  • Posts: 951
Re: Gtr oil feed
« Reply #3 on: December 26, 2018, 05:40:54 PM »
         I always fit the unions with the flat side uppermost against the seal washer and checkvalve head ;  open side down against the engine drilling. No real reason why, that's the way I've always found them fitted.
         The pump can only supply oil at a single pressure (as generated by the spring on the plunger shaft). This is fed alternatively to either cylinder so they both recieve the same pressure.

         My initial thoughts on the apparent oil leakback from the engine end was to suspect an air leak on the checkvalve sealing washers, the ball in the valve or even up the 8mm thread from the crankcase.  I don't think oil can leak back past the distributor valve and you can't find any external leakage so where's the oil going?     Karl may well be right that it is bleeding/syphoning forwards into the engine.
       Pull the checkvalve and rinse well in paraffin or similar. Do not put an airline on it, it will wreck the valve, just blow it through by mouth using a spare piece of tube.  If clean, it should provide an airtight shutoff when blown from the 8mm engine end. If you then suck you will feel slight resistance before the ball lifts and allows forward flow.

     
Unspoiled by progress.
I'm so glad I grew up in the 60s & 70s. I did so much stupid stuff and there's no record of it.............Anywhere !!

Offline AlanJohn

  • Trade Count: (0)
  • Full Bridgestone Member
  • ***
  • Posts: 216
Re: Gtr oil feed
« Reply #4 on: December 28, 2018, 05:13:18 AM »
Thanks for your advice but l can't get it right and for now l give up.
Will it do any damage using the bike with a 20/1 oil fuel mixture so it's running basicly without the oil tank connected?
Although it is connected but has an issue and probably not working correctly.
Thanks.
Alan.

Offline OldSwartout

  • Global Moderator
  • Trade Count: (0)
  • *******
  • Posts: 1314
Re: Gtr oil feed
« Reply #5 on: December 28, 2018, 07:48:55 AM »
IMO, you can run without an oil feed and not hurt the pump.  The pump drive gets oil from the crankcase and should keep the internals oiled, including the pumping components. Others may have some experience they can relate.
Karl Swartout
Mooresville, IN
BS175 Roadracer. BS200RS, BS350 GTR

Offline AlanJohn

  • Trade Count: (0)
  • Full Bridgestone Member
  • ***
  • Posts: 216
Re: Gtr oil feed
« Reply #6 on: December 28, 2018, 11:28:09 AM »
Thanks.
l watched the oil pump up to the union today but l don't think it's going past the union and then very slowly drains down the tube a couple of inches.
Do the pumps get weak over time?
If so a replacement pump and check valves will have to be done.
Thanks for your help.

Offline CL-100

  • Trade Count: (0)
  • Expert Registered Bridgestone Member
  • ****
  • Posts: 343
  • CL-100
Re: Gtr oil feed
« Reply #7 on: December 28, 2018, 02:13:45 PM »
Would it make sense to swap the two unions around and see if you get different results?  It may help pinpoint a bad check valve or perhaps an air leak in the line somewhere.

Offline AlanJohn

  • Trade Count: (0)
  • Full Bridgestone Member
  • ***
  • Posts: 216
Re: Gtr oil feed
« Reply #8 on: December 28, 2018, 02:30:43 PM »
Thanks but l've just found that both check valve (bolts) are the wrong ones for this bike hopefully that will cure it l'll let you know.

Offline AlanJohn

  • Trade Count: (0)
  • Full Bridgestone Member
  • ***
  • Posts: 216
Re: Gtr oil feed
« Reply #9 on: December 28, 2018, 02:31:29 PM »
Thanks but l've just found that both check valve (bolts) are the wrong ones for this bike hopefully that will cure it l'll let you know.

 


Gallery


Views:220
Comments (0)
By: Jon West

Views:1362
Comments (0)
By: rwgibbon

Views:1690
Comments (0)
By: Perry L Anderson

Views:1757
Comments (0)
By: Perry L Anderson

Classifieds

Gto
Date: 03/02/2024 06:49 am
Time Left:
Looking for a BS90 used or new luggage Carrier assembly

Date: 02/01/2024 04:19 pm
Time Left:
Gto
Date: 10/19/2023 01:08 pm
Time Left:
Urgent - l/end roller bearing & piston pins needed
Date: 10/08/2023 03:25 am
Time Left:

Recent Downloads added

Chibi, Chibi Deluxe, Tora Service Manual
Rating: (None)
Filesize: 20383.27KB
Date: May 01, 2023, 08:35:39 PM
Chibi_Tora_Parts_Manual
Rating: (None)
Filesize: 14301.44KB
Date: May 01, 2023, 08:25:53 PM
BS200 Mk II RS & MK II SS Exclusive Parts
Rating: (None)
Filesize: 358.29KB
Date: March 07, 2021, 07:30:10 PM
1970 sales brochure
Rating: *****
Filesize: 6753.33KB
Date: July 16, 2020, 10:01:18 PM

Powered by EzPortal