BritBike Forum logo
BritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike Sponsor SteadfastCyclesBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorHepolite PistonsBritBike Sponsor
Upgrade to: Premium Membership | Gold Membership | Life Membership | Vendor Membership | Site Sponsor Membership
Member Spotlight
trevinoz
trevinoz
newcastle australia
Posts: 953
Joined: July 2006
ShoutChat Box
Comment Guidelines: Do post respectful and insightful comments. Don't flame, hate, spam.
Search eBay for motorcycle parts in following countries
Australia, Canada, France, Holland, Italy, United Kingdom, USA
Random Gallery photo
a word from..
Manuals on DVD (Shipping included)
Previous Thread
Next Thread
Print Thread
Rate Thread
Gas in the Sump
#711646 10/15/17 1:50 pm
Joined: Aug 2002
Posts: 687
Britbike forum member
OP Offline
Britbike forum member
Joined: Aug 2002
Posts: 687
I have been chasing a problem on my 67 T120 and things got a bit more interesting when I found the engine full of gas. The bike came to me with a MAP belt drive installed and I have always found the clutch to be way too stiff. It also slipped on acceleration. When I removed the primary cover, I found two problems. One the clutch springs were way too loose. I think that may have been the prior owner trying to reduce the stiff feel at the lever. The other problem was oil in the primary that should be dry with a belt drive. I cleaned everything and adjusted the springs and that fixed the slipping problem and the stiff feel at the lever. I don't really understand how tightening the springs reduced the stiff feel, but it made a big improvement. After reading about problems with the MAP belt drives and leaking crank seals I decided to change my seal. When I removed the cover this time, I found gasoline inside and the green material on the alternator was breaking up in big chunks. When I removed the sump plug, a ton of gas came out. Now I am trying to understand just what is happening. I believe that I have two separate problems that just happen to occur at the same time, but after all that I have seen I want to make sure that they are not related. My theory is that the MAP belt problem caused the oil in the primary by deforming the seal and that allowed gas to get in the primary when the sump filled up. The gas in the sump has me confused. The petcocks were turned off and I always turn them off whenever the engine is not running. The only thing that I can think of is a bad petcock that allows gas to pass when it is turned off. Even then, one or both carbs must have a problem that keeps the needle and seat from stopping the gas at the float bowl. I have a hard time believing that given the amount of gas in the sump, but I can't think of any other way for gas to get inside the engine. As for the alternator coming apart, it could be the gas fumes in the primary attacking the putty covering the wire coils. My plan at this point is to replace the crank seal, replace the alternator, clean the needles and sets, and replace both petcocks. Does that sound like a good plan or can anyone think of a better explanation for what I am experiencing?

Thanks,
Doc


Doc

Mostly Triumphs with a few BSA's a Norton, and two BMW's

Support Your #1 BritBike Forum!

Check out British motorcycles for sale: British Motorcycles on e-Bay UK, British motorcycles on e-Bay North America
Re: Gas in the Sump
Doc_dup1 #711647 10/15/17 3:01 pm
Joined: Dec 2004
Posts: 10,793
Likes: 48
Britbike forum member
Offline
Britbike forum member
Joined: Dec 2004
Posts: 10,793
Likes: 48
Bad petcock or petcock left open is most likely to get petrol in the engine oil which then gets past the seal into the primary and the petrol ethanol eats the epoxy.

Re: Gas in the Sump
Doc_dup1 #711653 10/15/17 4:48 pm
Joined: Nov 2008
Posts: 3,203
Likes: 15
Britbike forum member
Offline
Britbike forum member
Joined: Nov 2008
Posts: 3,203
Likes: 15
Disconnect the fuel lines at the petcock to check for leaks. I'd replace the floats and seats and needles and check the ticklers to make sure they are not holding the float down.


1968 T120R
1972 T120RV
Any advice given is without a warranty expressed or implied.
Re: Gas in the Sump
Doc_dup1 #711665 10/15/17 7:05 pm
Joined: Aug 2002
Posts: 687
Britbike forum member
OP Offline
Britbike forum member
Joined: Aug 2002
Posts: 687
Thanks, I plan to go through both carbs, checking float levels, etc. I just want to confirm that I am not missing something obvious that would cause all of my problems.


Doc

Mostly Triumphs with a few BSA's a Norton, and two BMW's

Re: Gas in the Sump
Doc_dup1 #711669 10/15/17 7:52 pm
Joined: Jun 2007
Posts: 6,923
Likes: 16
Britbike forum member
Offline
Britbike forum member
Joined: Jun 2007
Posts: 6,923
Likes: 16
I'm wondering which alternators are subject to dissolving in the presence of gasohol and if there are any that are specifically potted to resist it.
Imagine what a mess it might make of your motor with this goo circulating through it. I caught this one before the owner started the bike. That was a close call.
Cheers,
Bill

[Linked Image]001 by William Dunlap, on Flickr


Bikes
1974 Commando
1985 Honda Nighthawk 650
1957 Thunderbird/T110 "Black Tiger"
Antique Fans: Loads of Emersons (Two six wingers) plus gyros and orbiters.
Re: Gas in the Sump
Doc_dup1 #711673 10/15/17 9:14 pm
Joined: Aug 2002
Posts: 687
Britbike forum member
OP Offline
Britbike forum member
Joined: Aug 2002
Posts: 687
For the record,mine was the same color green before it came apart.

Doc


Doc

Mostly Triumphs with a few BSA's a Norton, and two BMW's

Re: Gas in the Sump
Doc_dup1 #711697 10/16/17 3:53 am
Joined: Feb 2006
Posts: 919
Likes: 1
Britbike forum member
Offline
Britbike forum member
Joined: Feb 2006
Posts: 919
Likes: 1
Doc,

Your plan sounds good. One or both petcocks are passing gas. One or both carbs aren't sealing at the float needle.

The rest is just consequential damage.


'51 C11 in a '54 C10L frame. Back on the road...
'70 Triumph Trophy 500. Next on the bench for a refresh!
'72 Triumph Tiger 650. Back on the road...
Re: Gas in the Sump
Doc_dup1 #711701 10/16/17 8:33 am
Joined: Sep 2011
Posts: 1,059
Likes: 1
Britbike forum member
Offline
Britbike forum member
Joined: Sep 2011
Posts: 1,059
Likes: 1
Ensure the carb float needles are viton tipped.
Some very poor quality petcocks have been sold over the years.
Not difficult to spot which one is passing fuel when closed..

Re: Gas in the Sump
Doc_dup1 #711706 10/16/17 12:46 pm
Joined: Jul 2005
Posts: 71
Britbike forum member
Offline
Britbike forum member
Joined: Jul 2005
Posts: 71
do you have Mikuni carbs ? they have been known to cause this issue....

Re: Gas in the Sump
Doc_dup1 #711707 10/16/17 12:52 pm
Joined: Jun 2014
Posts: 230
Likes: 3
Britbike forum member
Offline
Britbike forum member
Joined: Jun 2014
Posts: 230
Likes: 3
Even when working at it's very best I would still only consider a carburettor float valve as a momentary interruption into the fuel flow , No matter what it's tipped with or what height it's been set at ? it's all but relying on a small movable brass seating that is hopefully 100% fuel tight .. ( Personally i very much doubt that ! ) ..

Added to the fact that even in a non-running engine fuel is likely constantly finding several different other ways by capillary or wicking up small jets and drillings into the throat of the carburettor > Without a good fuel tank petcock securely stopping the flow the whole process is just self-perpetuating ,
Been there done that !! .. i now give the cheaper taps a miss (the one's usually fitted with those pretty white nylon filters) .. The slightly dearer soldered brass gauze filter type are usually a better made item with a brass on brass tapered seal inside ,

remove the petcock > if you can't suck a vacuum on a closed petcock that'll stick to the tip of your tongue "Don't Use It" wink

Re: Gas in the Sump
Doc_dup1 #711710 10/16/17 2:28 pm
Joined: Aug 2002
Posts: 687
Britbike forum member
OP Offline
Britbike forum member
Joined: Aug 2002
Posts: 687
Thanks for the help everyone. I plan to get back on this project later this week, nothing like a 2 hour job that evolves into a 2 day project.

Doc


Doc

Mostly Triumphs with a few BSA's a Norton, and two BMW's

Re: Gas in the Sump
Doc_dup1 #711726 10/16/17 6:50 pm
Joined: Jun 2007
Posts: 6,923
Likes: 16
Britbike forum member
Offline
Britbike forum member
Joined: Jun 2007
Posts: 6,923
Likes: 16
On the bike in the picture, the fuel taps did not appear to be leaking. The operative word is "appear", as obviously they were. But the bike sat for over a year and one drop at a time, all the fuel drained out of the tank and into the carb, then then past the rings and into the sump.

A very good argument for properly storing your bike for long term.

Cheers,
Bill


Bikes
1974 Commando
1985 Honda Nighthawk 650
1957 Thunderbird/T110 "Black Tiger"
Antique Fans: Loads of Emersons (Two six wingers) plus gyros and orbiters.
Re: Gas in the Sump
Doc_dup1 #711740 10/16/17 10:58 pm
Joined: Jan 2017
Posts: 1,316
Likes: 23
Britbike forum member
Offline
Britbike forum member
Joined: Jan 2017
Posts: 1,316
Likes: 23
Hi Doc, I got these fuel taps 4 years ago. Taiwan made. I've tested them many times & even just recently. They do not leak. Have tested taps for over 2 months. No leaks. Fuel leakage is very costly so I try to keep on top of it.

eBay.

http://www.eBay.com/itm/FUEL-PETROL-GAS-TANK-TAP-VALVE-PETCOCK-SET-TRIUMPH-BSA-NORTON-T100-T120-TR6-TR7-/252283339344?epid=1991920016&hash=item3abd424250:g:6vwAAOSwe7BWu6kR&vxp=mtr

Also '67 was a change over year. Mono block or Concentric carbs. With either one very good to get genuine AMAL stay up float & viton tip aluminum needle. I have also tested these many times, again recently. They do not leak. If you have Concentric with nylon needle & floats that is a bike fire waiting to happen. Don't use the old nylon with USA fuel. I have personal experience with this.

Regarding fuel tap seals I find the new stato seal washers seem to work best with the sharp side of steel flat washer facing upwards against stato seal. I'm talking about the extra steel washer that is often installed between nut & stato seal. I also have been finding if I lube the seal with oil it tends to somehow find a way to seal a little better. It is said P-80 emulsion rubber lube is very best, but I haven't tried that yet. I just ordered some.

I've found the old original seals had a larger rubber area at threads & just worked. Now days the new ones I find can be temperamental. Maybe just me?? Even though they look the same in all the sellers photos I find the ones from Rabers tend to work better.
Don



1973 Tiger 750
Re: Gas in the Sump
Doc_dup1 #711774 10/17/17 4:15 am
Joined: Jun 2014
Posts: 230
Likes: 3
Britbike forum member
Offline
Britbike forum member
Joined: Jun 2014
Posts: 230
Likes: 3
Yup ! .. Them's the one's !! .. facepalm
I've had a couple of sets of them , Actually they work really smooth & 100% fuel tight for a couple of years but then > when you least expect it ??
first symptoms I noticed was bike starting to take an extra few kicks to get fired up .. I put this down to probably cylinders always being in constant state of moisture with fuel vapours 'who knows ?' .. The only way you'll ever test them on the bike is disconnect the union & wedge a piece of white paper towel up under it overnight , any staining next morning and it's a leaker .
I still got the old ones here in pieces >> Another feature I was never too happy with was the slip in rubber type seal or whatever it's made of ,
wouldn't take much for that thing to turn with the lever and block the flow - or maybe swell up even with some of this modern $hit fuel
Possible holed piston with every turn of the tap just waiting to happen there i'd say ..

[Linked Image]

In light of past experience - if I were to suggest a replacement tap i'd now go for this "Brass on Brass" type of sealing every time ..
http://www.eBay.com/itm/Triumph-BSA-2-UK-MADE-Quality-Petrol-Fuel-Taps-with-Tapered-Brass-Ethanol-Seal-/372047673912?hash=item569fc4fa38:g:cZIAAOSwkbZZlV1i

Re: Gas in the Sump
Doc_dup1 #711805 10/17/17 2:39 pm
Joined: Aug 2001
Posts: 4,355
Likes: 7
Britbike forum member
Offline
Britbike forum member
Joined: Aug 2001
Posts: 4,355
Likes: 7
I have to say I was a bit surprised to hear the Taiwan petcocks recommended. Some time back, (years?) on this site there was a thread on the issue of that "rubber" seal part swelling up and almost completely blocking the flow. I have avoided them ever since, but maybe the Mfr has changed the design now? If they worked for Bodie for years,..... That's a good test I expect. Does that gas have the ethanol in it? In the photo, the filter unscrews? Didn't know that.
Even with the above. When brass on brass is available, why not use it? Aside from the 3X$ issue, the only draw back is they seem to be hard to move sometimes. I attribute that to the cone seal doing a great job in it's seat. Possibly too much spring pressure on the cone? Dunno....... They do work.

Last edited by KC in S.B.; 10/17/17 2:41 pm. Reason: Poor spelling.......

Down to 1 BSA, 2 Triumphs, 1 '56 Chevy
1 '65 XLCH, Hernia Gift, on the way to Japan!
Re: Gas in the Sump
Doc_dup1 #711831 10/17/17 6:38 pm
Joined: Jun 2007
Posts: 6,923
Likes: 16
Britbike forum member
Offline
Britbike forum member
Joined: Jun 2007
Posts: 6,923
Likes: 16
Use a gas proof lubricant. John Healy knows of one or you can ask around the local airport.
The older big lever taps have the cone part going all the way through the body of the tap so you can effectively "unstick" them by banging on the back side of them with a blunt tool.

Not so with these. Eventually you will just break off the lever.

Cheers,
Bill


Bikes
1974 Commando
1985 Honda Nighthawk 650
1957 Thunderbird/T110 "Black Tiger"
Antique Fans: Loads of Emersons (Two six wingers) plus gyros and orbiters.
Re: Gas in the Sump
Doc_dup1 #711876 10/18/17 5:50 am
Joined: Sep 2011
Posts: 1,059
Likes: 1
Britbike forum member
Offline
Britbike forum member
Joined: Sep 2011
Posts: 1,059
Likes: 1
I have memories of those petcocks from the 80's. The rubber would swell and it got to a point that it didn't matter what position the lever was in. There was a slow trickle, not enough to run the bike, neither would it shut off. Of course I thought these would be all long gone. Doc, you got a couple of years!! I recall it was just a matter of weeks, or even less. At least you've solved the mystery.


Moderated by  John Healy 

Link Copied to Clipboard
Home | Sponsors | Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons | DVD- Manuals & Parts books
Upgrade to: Premium Membership | Gold Membership | Life Membership | Vendor Membership | Site Sponsor Membership
Powered by UBB.threads™ PHP Forum Software 7.7.4