Author Topic: Advice sought - FUEL TANK  (Read 844 times)

Offline 1200 JOTA

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Advice sought - FUEL TANK
« on: June 14, 2019, 19:03 »
I'm presently sorting out a 1200 Jota (America) that has Mikuni RS carbs. that are higher and wider than the Dellortos ... so the fuel tank has to sit about 3/4" high to clear the carburetors.

The present tank (although in good condition overall) has a couple of internal resin coats, so that precludes 'metal work' as a solution and I expect I'll need a new tank. After market is ok unless anyone knows of an OEM tank that might work. I need about 12" width at carb height to clear them.

(sorry about imperial measures .. metric is the go)
1975 Norton 850 Commando
1977 Laverda 1200 Jota America
1979 Ducati 900 GTS

Offline Grant

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Re: Advice sought - FUEL TANK
« Reply #1 on: June 14, 2019, 20:06 »
So your question is what?
Which tank will clear the carbs?
My solution was to raise the rubber mounts at the rear of the tank and to use angled inlet stubs with a 10 degree (I recall) flatter profile.
No issue with tank to carb clearance.


2019-06-13 13.41.06 by Grant Duguid, on Flickr
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Offline Brett

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Re: Advice sought - FUEL TANK
« Reply #2 on: June 14, 2019, 23:31 »
I'm presently sorting out a 1200 Jota (America) that has Mikuni RS carbs. that are higher and wider than the Dellortos ... so the fuel tank has to sit about 3/4" high to clear the carburetors.

The present tank (although in good condition overall) has a couple of internal resin coats, so that precludes 'metal work' as a solution and I expect I'll need a new tank. After market is ok unless anyone knows of an OEM tank that might work. I need about 12" width at carb height to clear them.

(sorry about imperial measures .. metric is the go)

You know your other option is to get onto RED and get a set of his angled manifolds then your problem is solved no need to mod the tank. Also he has found that the Mikuni's actually work better when they are more horizontal...
I have FCR's  which are down draught style on the Cico so had to kick them the other way slightly ... so they ware higher now than Mikuni's by a bit yet still managed to squeeze them under the tank without modding it.... all ya need is some out of the box thinking and lucky for you RED has done that for you on Mikuni's.

Love that Gold Paint Grant


Here's a set of Mikuni's with Red's set up nestling neatly under a stock tank at its normal height


« Last Edit: June 14, 2019, 23:40 by Brett »
Sitting on the fence 120 or 180 that is the question ?

Offline 1200 JOTA

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Re: Advice sought - FUEL TANK
« Reply #3 on: June 15, 2019, 02:24 »
The question would be " are there any production tanks or aftermarket tanks (possibly a larger capacity) that are not as 'waisted' as the regular tank on the triples?"

It's more aesthestic than necessary at the moment but a higher CG and a little too much rubber which will be prone to give in time which makes me want to source another tank if possible.

Another option is to take some good advice and reset the manifolds.

1975 Norton 850 Commando
1977 Laverda 1200 Jota America
1979 Ducati 900 GTS

Offline Laverda SF

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Re: Advice sought - FUEL TANK
« Reply #4 on: June 15, 2019, 03:22 »
You can do anything and shape a fuel tank but that last thing you want is a bomb under your ass.

Been there. After a 20 mile run on my SFO, back in 75, my Ass became Hot. The stock SF tank had a weakness and dripped gasoline on the battery.  I was lucky and did not go further until I fixed it.

Close call and a lesson well earned ;o)
« Last Edit: June 15, 2019, 03:53 by Laverda SF »

Offline lawrence

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Re: Advice sought - FUEL TANK
« Reply #5 on: June 15, 2019, 06:08 »
Why not simply commission Boba to make you a CF tank?  He will provide one with the clearance you require.

I have come to understand that Laverdas varied from bike to bike enough that it's not always possible for a fix that works on one bike to work the same on another.  Case in point is my own Mirage 1200 TS.  I have the angled intake stubs (lovely bits they are!) but I still need to raise the aft end of the tank to clear the Mikunis.
Idaho, USA

Offline Grant

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Re: Advice sought - FUEL TANK
« Reply #6 on: June 15, 2019, 06:51 »
I used the angled inlet stubs from Red and fitted a cable tie or two to the standard rubber mounts at the rear. The rubbers are quite long where they slide into the frame tube and a few mm less into the tube due to the width of the cable tie makes no difference to how they do their job. Mine have given no issue in 11 years of use.
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Offline Schurminater

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Re: Advice sought - FUEL TANK
« Reply #7 on: June 15, 2019, 11:57 »
I used the angled inlet stubs from Red and fitted a cable tie or two to the standard rubber mounts at the rear. The rubbers are quite long where they slide into the frame tube and a few mm less into the tube due to the width of the cable tie makes no difference to how they do their job. Mine have given no issue in 11 years of use.

Couple of o rings on the rubber mounts would do the job nicely too I would have thought Grant  (bigthumb)


Offline Brett

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Re: Advice sought - FUEL TANK
« Reply #9 on: June 15, 2019, 23:09 »
Hmm wonder if an alloy riser might help in the bedroom  (headnit)


Sitting on the fence 120 or 180 that is the question ?

Offline Dellortoman

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Re: Advice sought - FUEL TANK
« Reply #10 on: June 16, 2019, 04:10 »
Depends on the problem Brett. May be useful if one of the legs on your bed is a bit short.
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Offline Paul Marx

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Re: Advice sought - FUEL TANK
« Reply #11 on: June 16, 2019, 07:44 »
Hmm wonder if an alloy riser might help in the bedroom  (headnit)

I have a urine riser, twice every night.

Paul

Online Vince

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Re: Advice sought - FUEL TANK
« Reply #12 on: June 16, 2019, 07:56 »
I am sure someone with plenty of time and money could find an artisan to build an alloy jellyroll, my favourite shaped tank.

Offline Piranha Brother 2

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Re: Advice sought - FUEL TANK
« Reply #13 on: June 16, 2019, 08:32 »
I am sure someone with plenty of time and money could find an artisan to build an alloy jellyroll

an alloy jellyroll  :-\ ???  Or is that a jelly alleyroll? WTF is this thing?
What ... leave it standard??!!

Offline TC

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Re: Advice sought - FUEL TANK
« Reply #14 on: June 16, 2019, 09:07 »
Hmm wonder if an alloy riser might help in the bedroom  (headnit)
From what Ive heard... Aluminium is not that popular in the bedroom, bit cold and sharp :( so no Brett may not be that helpful, except as Cam said  :)
Most of that will polish out...

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