Petcock hitting flatslides on new build (38's)

[HWB]

748 d.ot head on 1127 N, couple of things preventing me from completing the build, 

1- carbs wont go in the boots not even with ratchet strap. (Yes they are the correct boots, spacing on carbs is a bit off, might dremel boots)

2- fuel tap is hitting the carbs from what i can foresee, what if any solution do i have other than running a pingel tap, and if thats the only option which pingel have u guys used, there seem to be many options, i need the one that will work.

 

Cheers guys

[Upshotknothole]

You can add some spacers to the back of the tank, or go with a Pingel. The Pingel needs an adapter plate, but if space is really tight, you can get a bung welded directly to the tank instead of using the adapter. 

http://www.pingelonline.com/motorcycle-fuel-valves/dual-outlet-32gsxr-d-ah.asp

[Dezza]

1100n"s have BST 40 carbs so RS38s should go into the rubbers OK, assuming you are using your 1100 carb rubbers. The dot head inlet ports are set at a steeper angle to other oil-cooled heads meaning that for some engine/dot head/frame/tank combos clearance issues will arise. Rubbers from a 750l,m will accept Rs carbs and bring the carbs 5mm closer to the head than rubbers from an 1100. It's all in the sticky thread at the top of this section .

[HWB]

My 1100 rubbers are way to wide for the rs38s so im using the ones from a 1100 that had 36bst which have an id of 42 but are shrunk as heck, anyway im more concerned with the petcock clearance, ill check that sticky once again maybe i missed something

[Joseph]

RS36 and RS38 are the same size as your BST36 so will fit the BST36 rubbers indeed.

But like you said, on crusty old rubbers, it will be a very demanding job to push any carbs on.

I gave up on a tank fitted tap, just used an alloy plate and brass spigot, maybe due to the clearance issues the dot head seems to have created that could be a solution for your situation ?

[Upshotknothole]

RS 38s tend to be a bitch to get in, try putting a little oil on the boots when forcing them in, and I've used everything from a ratchet strap to a 2x4 to get them to slide in. If your boots are really that hard and shrunk, it might be time to replace them before you start getting intake leaks.

 

You could always blank off the petcock hole and get a bung welded in slightly forward where you have more room, or even move it to the rear of the tank. Is this an 1100 frame or a 7/11? I think the pingel off of one of the GSX-F models had a reserve, but I didn't see them listed on their website anymore, so not sure if they're still available or not.

[HWB]

Ok so i got the pingel with the offset spacer, now the tank hits the throttle cable on the carbs, would you bend the tang the cables go through on the carbs or lift the tank with spacers like upshotknothole suggested and if so how can i space the tank ?

On 3/10/2022 at 9:51 PM, dago said:

Just checked mine, 50mm on 38s are the same, slight gap, think it might be because there's a slight radius on the back of the flange, looks like they're spun so part of the manufacturing process

 

[slayer61]

On 5/9/2022 at 2:53 PM, Upshotknothole said:

RS 38s tend to be a bitch to get in, try putting a little oil on the boots when forcing them in, and I've used everything from a ratchet strap to a 2x4 to get them to slide in. If your boots are really that hard and shrunk, it might be time to replace them before you start getting intake leaks.

 

You could always blank off the petcock hole and get a bung welded in slightly forward where you have more room, or even move it to the rear of the tank. Is this an 1100 frame or a 7/11? I think the pingel off of one of the GSX-F models had a reserve, but I didn't see them listed on their website anymore, so not sure if they're still available or not.

I just finished a similar task recently. My welder cut off the spout/tap mount, welded the hole shut and reinstalled the spout a couple of inches forward to clear the Mikuni RSs

[Dezza]

The throttle cable crank assembly can be positioned to the end of carb 1 but then a different throttle shaft (available from RS dealers) is required to do this. It's on the parts list in the booklet supplied with a set of RSs. This will likely solve your tank fouling problem

[HWB]

11 minutes ago, Dezza said:

The throttle cable crank assembly can be positioned to the end of carb 1 but then a different throttle shaft (available from RS dealers) is required to do this. It's on the parts list in the booklet supplied with a set of RSs. This will likely solve your tank fouling problem

Dezza thanks for always being here and helping man. Really appreciate it.

 

Ill look it up

[Dezza]

It can also be re-positioned to between 1 and 2 or 3 and 4 without the need for any additional parts but from what you describe this will be unlikely to solve your problem.

[george 1100]

On both my 7/11 builds, I cut and shut 10mm off the bottom of the fuel tank sumps though I wouldn't have done that if I wasn't repainting

[HWB]

16 hours ago, george 1100 said:

On both my 7/11 builds, I cut and shut 10mm off the bottom of the fuel tank sumps though I wouldn't have done that if I wasn't repainting

Can you explain more please ?

[george 1100]

8 hours ago, HWB said:

Can you explain more please ?

Something like this. Cut 10mm strip all around and weld back together. If you cut more than 10/12mm, the OEM petcock handle will interfere with the underside of the top chassis rail. 

You can cut more than 10mm if you use a pingel 

Obviously, fuel capacity will be reduced

Edited May 14, 2022 by george 1100

[Dezza]

I think he means the bottom of the tank now fouls the top of the throttle crank bracket on the carbs. If this is correct, I guess the solution is either: 1) move the throttle crank, 2) raise the tank or 3) cut a section out of the bottom of the tank and weld in a bubble/recess in the tank to clear the throttle crank bracket .

[HWB]

tried raising the tank. That didnt work. The gap is just embarrassing. Went on mikunis website and couldnt find the conversion kit for a side pull kit and even if i did i think it wont clear anyways. Guess ill need to cut the tank and make a bubble like dezza said. 

On 5/13/2022 at 11:34 PM, george 1100 said:

 

 

[george 1100]

Bubble may not flow fuel from the bottom of the tank

[Dezza]

According to my RS manual there are 3 different throttle shafts. Confusingly, 2 have the same description and no detail as to any diferences in function are provided.

Shaft, throttle B/C #3 part no. 700-17011

Shaft, throttle B/C #1 part no. 700-17012

Shaft, throttle B/C #3 part no. 700-17013

Maybe email or call Allens and describe the problem. I have found recently when I converted my RSs to cable choke operation that giving them part numbers helps.

 

ps HWB, if you PM me your email address I can send you a pdf file of the RS manual.

Edited May 15, 2022 by Dezza

[Otatts]

@HWBi have a 1200 in an 88 750 and clearance was an issue. We heated to bottom of the tank and gently dented a shallow channel in the bottom of the tank to clear the throttle cables.

the Pingel tap didn’t work for me as there was not enough room so I had to make my own using an external Pingel vacuum on/off valve and a quick release fuel line. Flows great, compact and easy to remove the tank now. You can have a look at my build thread (time for a head job) it should be towards the end 

[HWB]

44 minutes ago, Otatts said:

@HWBi have a 1200 in an 88 750 and clearance was an issue. We heated to bottom of the tank and gently dented a shallow channel in the bottom of the tank to clear the throttle cables.

the Pingel tap didn’t work for me as there was not enough room so I had to make my own using an external Pingel vacuum on/off valve and a quick release fuel line. Flows great, compact and easy to remove the tank now. You can have a look at my build thread (time for a head job) it should be towards the end 

Just saw your thread, very neat project u got going on there mate, loving the fabs. 

Im gonna need at least 5 cms of clearance for those cables and i just dont think i can heat and hammer it down that much. Making the bubble seems like the best soulution so far. 

[Captain Chaos]

3 hours ago, HWB said:

Making the bubble seems like the best soulution so far. 

EFI and turbo is the best solution.

[HWB]

On 5/15/2022 at 2:57 PM, Otatts said:

@HWBi have a 1200 in an 88 750 and clearance was an issue. We heated to bottom of the tank and gently dented a shallow channel in the bottom of the tank to clear the throttle cables.

the Pingel tap didn’t work for me as there was not enough room so I had to make my own using an external Pingel vacuum on/off valve and a quick release fuel line. Flows great, compact and easy to remove the tank now. You can have a look at my build thread (time for a head job) it should be towards the end 

Just saw your thread, very neat project u got going on there mate, loving the fabs. 

Im gonna need at least 5 cms of clearance for those cables and i just dont think i can heat and hammer it down that much. Making the bubble seems like the best soulution so far. 

[HWB]

Sorry for the double post.

 

Anyone know the thickness of aluminum on the gas tank ? Im going to cut it and make a bubble and reweld, gathering materials so i guess its around 1mm ? Is it 2mm ? Anyone know for sure ?

[Upshotknothole]

58 minutes ago, HWB said:

Sorry for the double post.

 

Anyone know the thickness of aluminum on the gas tank ? Im going to cut it and make a bubble and reweld, gathering materials so i guess its around 1mm ? Is it 2mm ? Anyone know for sure ?

They're steel and if you remove the petcock you can measure the thickness of the bottom of the tank, it's pretty thin metal.

If you want to move the throttle pull to the left side, there's a thread with the part numbers.

https://oldskoolsuzuki.info/forums/topic/12676-left-side-pull-mikuni-rs-flatslide-carbs/

[Upshotknothole]

The Sudco part number should be Sudco P/N : 002-905 it's listed wrong in that thread.