Result of using Gasohol 95 in my old Triumph

Discussion in 'Technical' started by ianyonok, May 4, 2009.

  1. I have tried using gasohol 95 in my '71 Triumph Tiger and have seen some effects.

    1. About 7 years ago, I put Petseal in the tank (epoxy coating to seal any rust areas). This has now fallen off in big lumps, I thought due to age but it's the gasohol.
    2. The throttle slide in the carburettor got sticky to the point where it was jamming. I had to clean out a very sticky residue on the inlet side of the carb.

    3. The fuel lines from tank to carb, cracked and split after just a few weeks.

    I have now found a Shell garage that sells 95 Benzene in Mae Chan (none in Chiang Saen), it's on highway 1 other side of the road from Lotus. They told me it's only sold in Shell stations now.
  2. Hi Ian - So you found out the hard way and your results are exactly what I heard could occur on older machines using gasahol. I use plain 91 octane standard petrol in my Faser 2001 and it performs well.

    Regards Ken F
  3. Trust Me There are Hardly any New Bikes Designed to Run on the Shit :shock: The Phantoms included Slash :oops: The Stupid Little Sticker on the Tank stating 91 Gasohol OK is only there to Entitle the Manufacturer to Tax Rebates :idea: Noticeable Difference to the Raid & KLX since using Shell 95 V-Power 8) Actually More difference than the Exhaust etc :? I don't Notice much difference in the Tiger 1050 though which surprised Me :( The Longer You have a Bike or even Worse let it sit without starting it will be the True Revelation :evil: Continuous Use probably doesn't matter much :?:
  4. Thanks for the comments, guys.

    I put gasohol in the tank because I needed to know what the effect would be, as I dont live in a large town, so have limited choice of juice. As I maintain my classic bikes myself the results were no hardship as I enjoy pulling the bike apart for maintenance.

    With Amal Concentric carbs, you need to pull the slide every now and again anyway because the bodies warp with time/age/heat/use. That is actually why I pulled the slide out anyway, I assumed that is what had happened again. In fact after I had cleaned the gasohol residue out, the slide was still jamming slightly due to this reason. A few minutes with some 1200 emery and job done.

    The fuel lines are also easy, hose clips are unnecessary if you get the right size oil lines, just a push-on fit. Of course if they split while riding it's a different story. However, if you haven't set yourself on fire, you can buy this type of hose anywhere, no fttings involved.

    91 octane wont work too well in my Tiger as it has high compression 9:1 pistons. It should have 97 octane leaded fuel, now long unavailable, so it pinks even with 95 (retarding the ignition timing helped only a little).

    I consider modifications unnecessary and will probably have to use 95 gasohol again sometime due to where I live. So I needed to know what the issues were.

    I think the point about leaving the bike standing with gasohol in is valid. Maybe the residue wont build up if you use the bike every day. Although I had replaced the fuel lines and they split in a few weeks, it was old stock line, about 4 years old (probably too old for this climate), so maybe new lines will last longer. Maybe some oil / fuel line sold these days is more ethanol resistant too.

    All in all though, I will try to keep with the 95 benzene while they continue to sell it. I'll just have the shake out the lumps of petseal when it's all fallen off and live without it.

    It maybe that in the future 95 benzene wont be available, so I think the more knowledge and experience we have on the effects of ethanol mixed fuel, the better.

    Ian :)
  5. Ian if its any help my 2001 faser 1000cc uses 91 petrol ( with no pinging ) as previous owner fitted to timing a advanced mechanism so running 3 degrees above standard setting. JohnnyE is his name he is also the keen Triumph bike buff in Chiang Mai.

    Regards Ken F
  6. Ken,

    Thanks. To be honest, I cant remember now (and not at home to check) which way I moved the timing, but it was specifically due to using lower octane fuel (pre-gasohol days). This did help a little. You bike probably has lower compression pistons so could use lower octane fuel than mine anyway. I can use 91 in the '59 Thunderbird, I think 6.5:1 pistons, but not the Tiger.
    I've had Triumphs since the '70s, spent three years rebuilding the Thunderbird, have a great workshop as you saw and most special workshop tools for rebuilds. I know these bikes pretty well now...
    I'll pm JohnnyE sometime.

    See ya

    When you put gasohol the first time, after along time of pure benzine use, the alcohol part in the gasohol will immediately start to clean up your tank and carburetor. That will cause you a lot of residue to join the gasohol into your carburetor and cause problems. Since you have a rusty tank repaired with epoxy, the alcohol will attack the rust between the tank surface and the epoxy making the epoxy to fall off and maybe also soften the epoxy so that epoxy residue joins the fuel flow. That may have caused the jamming of the slides. As an old Triumph owner I think that jamming slides was an "original" feature of Amal Concentrics. They had to be fixed with regular intervals due to aluminum corrosion.

    Your problems with the gasoline lines are also quite natural, maybe they were not gasohol resistant, but since the problem occurred so quickly I think, they were just so old so that, when you put gasohol, the alcohol attacked the old rubber and they started to leak. We also have to remember that all rubber parts deteriorate more quickly here in Thailand's climate.

    It is so long time since I last time opened a Concentric so I don't remember if there is any o-rings inside. I think there maybe one, sealing the float needle seat into the floating chamber. If there is one I would recommend to change it or those (I think you said you have a Tiger and that should be a one carburetor model} If there are other o-rings inside the carburetor, change them just to be sure. There is one O-ring under the pilot air screw and one for the throttle stop screw both on the out side. Change them. If you want to "over do", change also the O-rings on both side of the manifold.The sealing between the floating chamber and the the carburetor housing used to be a paper gasket, they may have changed it on newer models using a O-ring. If so change it. All automotive O-rings today are gasohol resistant. Now your bike is Gasohol resistant.

    When it comes to to your tank, you probably will have to have it cleaned properly. Cleaning tanks inside is a difficult problem. What I have done is to take off the tank and spray it inside with rust preventing/eating spray and let it be for a while, maybe a few days. Then have the tank washed inside by a high/pressure, preferably hot water jet. There are models were you can mix the water stream with sand or small glass balls that will effectively take away the rust. These machines must be available here in Thailand also, but probably you can get along with any high pressure washing machine you can buy, at any Tesco/Lotus. The problem is often that the spray gun is not very flexible so it is difficult to get inside the tank effectively. I used to put a flexible thick rubber hose at the end of the spray gun and then let the rubber hose "fly around" inside the tank. After the wash you have naturally to dry the tank at once. If you use sand or glass balls with the water you will get a 100% clean metal surface. All temporary solutions like epoxy or rubber based liquids inside the tank will cause problems in the long run. Of course it is also good to use gasoline filters between the tank and the carburetor.

    Good to remember also is that the rubbish from your tank normally will never go into your carburetor when using the main tank. The problems normally occur when you turn to reserve and the carburetor starts to take gasoline from the bottom of the tank.

    When it comes to compression the Gasohol 95 is 95 octane, the benzine part is probably "lower grade" benzine due to the fact that alcohol works like a octane booster with its higher octane. Your bike will for sure need 95 and I assume it still waits for leaded to come back.....If you need higher octane go and buy a can of Toluene and use that in very small proportions and your octane goes up. In the early 1970's all Turbo Formula ones were running on 86% Toluene technics developed by Honda with the gasoline being preheated in the exhaust system. Sounds dangerous.

    Gasohol and old Triumphs is not a new thing. In my old home countries Sweden and Finland, we drove also old Triumphs with "home made" Gasohol. We had to put alcohol in the gasoline now and then during winter time and early springs and late autumns. Petrol stations sold ethyl alcohol with something mixed in it to make it undrinkable and we had to put a half liter now and then to prevent the water drops in the gasoline to freeze. But in practice it was the same Gasohol that is sold today but maybe the mixture was a little more strong. Of course we had problems with the bikes, but we never blamed the Gasohol and frankly speaking I think that most of the problems were Coventry related...

    I think that 90% of all Gasohol related doubts are between the ears of the person who doubts. There is no mystique about Gasohol.

    It is interesting to see how many people already have get used to Gasohol and have found that nothing really change, it seems that even Monsterman have partly changed his mind, put Ian Bungy continues his war.....

  8. Yes HIKO is correct replace old O rings ,hoses and carb parts with modern bits and the carbs should be Gasohol friendly.
  9. Hiko,

    Some very good points, particularly your first two sentences. This may be exactly what I’ve experienced.

    "When you put gasohol the first time, after along time of pure benzine use, the alcohol part in the gasohol will immediately start to clean up your tank and carburetor. That will cause you a lot of residue to join the gasohol into your carburetor and cause problems."

    Actually the tank wasn’t that rusty, it just seemed a good idea years ago to seal it with Petseal Epoxy. Some of the epoxy could have dissolved and joined the fuel flow to become residue together with any accumulated detritus from the tank.
    I have never had problems with corrosion in Amal carbs, but it is a known fact that the Mark 1’s warp as they were made of cheap “mazac” alloy (so were the Monobloc carbs but they suffer this fault less I believe). But that’s not a major deal, it happens over a long period of time (not really part of this discussion anyway).

    The fuel lines were old, so Yes, that fault could be age related. However, in the past, using regular petrol, these lines have shown their deterioration by tiny cracks in the outer skin of the hose where they are stretched to go over the connector pipe at tank and carb banjo bolt. After using gasohol, the fuel line split open. Inconclusive though.

    There is no O ring on the float needle but a Viton rubber tip (probably petrol resistant, it’s still in use for seals today). There are O rings on the throttle stop screw and pilot air screw. No O ring on the float bowl flange only the thick paper gasket. There is an O ring on the inlet manifold flange, which is not an issue as I always fit a paper gasket here as well.
    Without knowing the compound of the rubber used for the O rings it’s impossible to know at this stage if they will be affected by the gasohol, but I would doubt it, more than likely I don’t need to change anything in the carb. Anyway I’m not going to change either of them yet, but will wait & see what happens. Amal made carbs for running drag bikes on alcohol mixed fuel.

    The tank cleaning idea sounds good, but probably unnecessary in this case as the rust is minimal. On this machine I have filters on both fuel taps and always run the fuel down to use the reserve as this is still a good amount of juice.

    The use of Toluene as an octane booster sounds interesting, maybe I’ll try that one day.

    As far as using gasohol, I think the “cleaning” point you have made is important. Thank you for pointing that out. It may be just the change to this fuel that has shown up these issues. None of which I find a problem, just need to understand what is happening when using this fuel.

    Oh and by the way…… Triumph’s Coventry factory was destroyed by the Nazis in the Blitz of 1940. After the war, Triumphs were built in Meriden.

    Regardless of anyone else’s opinion, my old Trumpets are my Mia Noi’s and much like my Mia Luang they have their foibles, but I love them all and wouldn’t ride anything else!


  11. Hiko,

    No sorry. By '71 they had a badge common to all.


    timingcoverbadge. [/code]

    Attached Files:





  13. Hiko,

    Thanks for the points you made, my brain wasn't capable of working out what was happening with the gasohol. Whatever faults Meriden Triumphs might have they are classically beautiful engines.
    Hinckley Triumphs... I'm afraid I know little about them. Pikey was good enough to let me try his Bonnie a couple of months ago (thanks mate) and very nice it was too. Felt very smooth and powerful (no vibes to make the fingers numb?). But then, I haven't ridden any decent size bike but my old Trumpets since the mid eighties when I had a Suzuki Katana overbored semi-race 1100 (poor handling rocketship) and a Ducati 900 SS desmo (wonderful handling uncomfortable beautiful niggly semi-racer).

  14. strange thing about alcohol is that in th UK I often have to ad ISOPROPYL ALCOHOL ratio 1-50 gasoline to stop carb icing in my carburettered Ducatis.
  15. Ian,

    You were welcome to try my modern Bonnie and glad you enjoyed it. I may well be in your area next month for my 90 day run so maybe we could hook up. BTW, I have been running mine for 18 months now almost exclusively on 91 gasohol (low comp engine) with no ill effects apart from the reluctance to start after being stood for a week or more. I get the same with my year old yammie Nuovo Elegance and because if this, if I know I am going to "lay up" the Bonnie for any amount of time, I'll make sure the last tank in regular non-gasohol 91.

    Yep, Hiko previously identified the "scouring" properties of the alcohol in gasohol and once you have remedied them by cleaning your carbs, replacing rubber items with more modern gasohol tolerant ones and tipping out chunks of Petseal, you'll prob be fine for miles to come.

    BTW, I had an 1100 Katana back in 1985, went UK-Holland-France-Spain and back on it - rocketship but bloody uncomfortable, especially 2-up! Would love another one though.....


  16. Never used 91 gasahol in my Bonnie only the 95 & have had no problems in 18,200 miles so far. Just the same, I agree with Pikey - when mine was parked up for the Songkrahn carry on I made sure the last tank was 91 Benzene. If you do come down next month Jeff, I think Ian is home at that time, maybe we can all meet up!
  17. Monsterman,

    Why would the carbs ice up I wonder, are we talking wintertime and cold air?
    I remember my SS sounded wonderful when winding on the throttle; those big Dell Orto pumpers going ssslllluuuuuuuurp through the velocity stacks with a bit of mesh over the top.

    Pikey, I spent a grand on my Kat back in '83 (I think), Yoshimura stage one cams, smoothbore carbs, overbore to 1150, K&Ns, 4 into 1 exhaust. It was almost unrideable below 70mph! Threw it into armco barrier on the M5, couldn't get it round the bend on the island. Pre spy camera days, I'd been doing about 130 or so down the motorway, it's then amazing how short those exit roads are....

    David & Pikey, Yes nice one, I should be back around 7th June.

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