would fcr's fit with this setup ?

[HWB]

good day

heres the deal, bike is a 1992 gsxr with the original 1127 shortblock and do.t head ported and everything, bike came originally with the 40mm carbs but now im running mikuni 38mm rs with no issues, the other day i removed them for maintenance and went to install the original 40's but they wouldnt fit, they hit the frame under the tank, problem is ihave the carb boots port matched with the head, they would probably fit if i put the 40mm boots on but that would be a big mismatch and it would probably run like crap,

 

question is : since my rs fit perfectly without hitting the frame, would the fcr39 clear ? are they taller ? im asking before dropping 1200$ on carbs that wont fit and cause a huge headache.

 

cheers

[spiderpig]

Why not stick with the rs38s? 

The dot head has a steeper inlet track so the stock carbs can hit the fuel tap. I haven't heard of them hitting the frame. 

[HWB]

what size stock carbs, my40mm hit the frame

[Duckndive]

41 minutes ago, HWB said:

what size stock carbs, my40mm hit the frame

its not carbs its engine 

the dot head is from a 750 so more room for the carbs under tank and frame

dot head on 1100 carbs hit things 

and FCRs are taller than RS carbs they also tilt back as well 

 

Edited September 22 by Duckndive

[HWB]

my 38 rs barely clear, so you reckon the fcr wont fit since theyr taller ?

[Duckndive]

4 minutes ago, HWB said:

my 38 rs barely clear, so you reckon the fcr wont fit since theyr taller ?

no idea just pointing out the difference 

maybe google FCRs and see if there are any clues or dimensions 

[Upshotknothole]

Pretty sure the dirt bike carbs are the same size as what gets used on the GSXRs. The dot heads move the carbs up more than any other head, and those stock 40mm CVs are huge, as well as being a pain in the ass to jet without an airbox.

If you know anyone with a dirt bike with an FCR carb, see if you can borrow it and test fit it.

 

Also a quick search gave me this photo. There's a fair amount of clearance on the side, but can't see how much clearance there is around the petcock or throttle cables.

[HWB]

thanks for the pic but are you sure that bike has a d-ot head on ?

[Upshotknothole]

6 minutes ago, HWB said:

thanks for the pic but are you sure that bike has a d-ot head on ?

Nope, didn't say anything about it having a dot head on it. You'll need to measure how much taller your dot head is vs a standard head. Top of the intake to the top of the carb should be enough to figure it out. Or, borrow an FCR off a dirt bike and see if it clears.

Can you post up a photo of how much clearance you have with the RS carbs on the bike?

Also, I'm pretty sure the FCRs won't fit your intakes you have port matched for the RS carbs. FCRs are bigger.

[HWB]

Top of the carbs have about 2 centimeters to the frame and the stacka about 2millimeters so virtually nothing

[Gixer1460]

On 9/22/2024 at 11:19 AM, HWB said:

question is : since my rs fit perfectly without hitting the frame, would the fcr39 clear ? are they taller ? im asking before dropping 1200$ on carbs that wont fit and cause a huge headache.

whilst the fcr39's are bloody nice - why not just fit RS40's ???

[baldrick]

because the fcrs are better carbs, thats why.

id sooner fit a std head with fcrs rather than a dot head with rs40s

Edited yesterday at 10:34 AM by baldrick

[Duckndive]

21 minutes ago, baldrick said:

because the fcrs are better carbs, that's why.   "THAT'S QUESTIONABLE"

id sooner fit a std head with fcrs rather than a dot head with rs40s

But the OP has said he has a dot head ....so why would he want to remove it dropping a little CR for a stock head   

Dept on full motor spec 40,s could well be overkill anyway 

[george 1100]

Is there an issue with the rs38's? The bike should sing along quite well with those if they're set up correctly. Can't see that there would be much to gain by going to fcr39's without some other accompanying mods and then may as well go to 41's

[jonny1bump]

You have to beat on tank to get fcr to fit nicely on m head, the dot head is higher ports and at an angle, quite a lot different.

The biggest difference you can make is to make a nice fat airbox to fit.

Edited 9 hours ago by jonny1bump

[george 1100]

Camera angle deceiving but 80mm is centre to highest point(rs measure 74) and 80mm from face of carb boot to furthest point at the top

[Captain Chaos]

sell the RS38's to me

cheap

[HWB]

8 hours ago, george 1100 said:

Camera angle deceiving but 80mm is centre to highest point(rs measure 74) and 80mm from face of carb boot to furthest point at the top

Thats exactly what i needed ! Cheers mate

[HWB]

21 hours ago, george 1100 said:

Is there an issue with the rs38's? The bike should sing along quite well with those if they're set up correctly. Can't see that there would be much to gain by going to fcr39's without some other accompanying mods and then may as well go to 41's

You wouldnt belive my luck, bought them brand new ran gor 1 month then broke idle screw in carb body#1 not nothing will take the broken piece out, i wish i could source just 1 carb body

[Duckndive]

2 minutes ago, HWB said:

You wouldnt belive my luck, bought them brand new ran gor 1 month then broke idle screw in carb body#1 not nothing will take the broken piece out, i wish i could source just 1 carb body

I still have some spare bodies some ware i will have a look tomorrow 

 

[baldrick]

8 hours ago, george 1100 said:

Camera angle deceiving but 80mm is centre to highest point(rs measure 74) and 80mm from face of carb boot to furthest point at the top

im presuming thats a dot head then aye?

[HWB]

19 minutes ago, Duckndive said:

I still have some spare bodies some ware i will have a look tomorrow 

 

That would be freaking awesome ! Please let me know 

[HWB]

10 minutes ago, baldrick said:

im presuming thats a dot head then aye?

Doesnt really matter i now have a reference and can measure to see fitment

[george 1100]

1 hour ago, baldrick said:

im presuming thats a dot head then aye?

Nope