fitting bst38ss to a bandit questions

[boilerdude]

Ok Ive got them fitted to the bike and almost ready to run. Here's the main things Ive run into so far. Just to round it up and put it all on the first post.

You need the bigger intake boots off of the gsxr 750.

You need to use the bandit petcock but you also need one small part off of the gsxr750 petcock. Just the vacuum thingy off the back of it. Swap that onto the bandit petcock. yes it's only 4 bolts instead of 5 It's fine just put the gsxr one on there. You will need to grind down 2 tiny plastic posts on the plastic gasket mating surface of the bandit petcock. Since the gsxr vacuum port does not have those holes... Then you will need to grind down just a millimeter or two off of the bandit petcock indicator between the "Prime" and "On" positions. Just a little tiny bit... Also you need the spring out of the gsxr petcock vacuum port... It works fine. 

2 fuel lines on the gsxr carbs. Only one line coming out of the bandit petcock. Use a t fitting. simple enough.

Some plug wires may need rerouted so you can fit that weird black filter box thingy the 38s have. 

The fuel hoses dont fit just in front of the K&N filters like you would think they ought to. You'll have to run a line back around the filters or squeeze the 2 fuel lines in front of the rack thingy and smush them in there beside the float vents. 

 

 

Edited May 19, 2017 by boilerdude

[Captain Chaos]

Use the 38mm intake rubbers on the B12 engine. They might be "offset" a bit, but as long as they seal correctly it's no problem.

If you block one fuel supply then those 2 carbs won't get any fuel. Use a T-piece between the two fuel lines and connect that to the fuel tap.

The 38mm carbs have two float bowl vents (thinner rubber pipes between 1&2 and 3&4), route them over the air filter somewhere near the battery. Leave the ends open. The fat pipe between 2&3 can go to the plastic box bolted on the breather cover

1 hour ago, boilerdude said:

Now what about that big fat lower hose that routed back into the airbox on the 750? What I do with that one? Just pull it?

if you mean the crankcase breather, it depends on the air filter setup you have.

As for jetting, it depends on the exhaust and air filter and camshafts and ignition timing and more stuff, main jets should be around 150, start from there. Mine has only bigger main jets, pilot screws turned out a bit more, everything else standard 750 settings.

[boilerdude]

O ok I didn't realise they were separated. I thought maybe one fuel line was seperate for reserve for whatever reason. Also what air filters? Please link to the exact ones. US friendly if possible. 

 

I'm gonna go have another look tomorrow. It seems this one hose came off with the carbs but it's not... with... the carbs. It's just kindof run through them for some reason... We'll get this straightened out. You've been tremendous already. thank you. 

Edited May 11, 2016 by boilerdude

[boilerdude]

Also here in the states of course we didn't get the special "power jets". I could install them but stock is zero. Does yours have the powerjet thingys?

[Captain Chaos]

the crankcase breather goes from the rocker cover to the air filter box. If you use the airbox just leave it as it is, if you use separate filters (K&N RU 2922 for example) the hose can go into a small can or bottle or whatever (just don't seal it, it should breathe) or to a small separate filter.

Powerjets came blocked off from the factory in all markets. Mine are also still zero.

[boilerdude]

Roger that. I'll try the 155. I have 89 750 cams. 5 degree advancer (holeshot). K&n (ru2922s...). And my bike even now with the 36s seems to like the 155.

hey I have another curiosity though... Over on customfighters I saw someone rather knowledgeable about suzukis make this post..."   rather than K&N filters get ram air foam filters and fit them over standard airbox rubbers , you'll get a much better set up on the carbs ".

now this was regarding bst36 I believe but I wish he would have elaborated on which filters are the ones exactly. And then also the same question but for bst38ss of course... I wonder if we've all been doing it wrong with these k&ns.

Edited May 11, 2016 by boilerdude

[boilerdude]

the previous owner of the 750 wildly spraypainted over a few things. so those intake screws are in there pretty damn good. I need a massive phillips bit. we'll get there. 

[Gixer1460]

Query - why fit 38's when 36's will generally suit mild to semi wild ? Always though 34's would probably produce a stonking road engine!

[Venom]

because 38s works much better and you can achieve  more HP . I have 38mm in my B12 and I will never back to 36 mm.

 

[Gixer1460]

Quantify that - how much better ? with associated engine mods?

[boilerdude]

A handful of people from OSS saying they work is good enough for me to try it anyway. Just because 36 is all it came with doesn't mean the engine couldn't run better with bigger ones.

Its not always just a ported big bore big valve engine that needs bigger carbs. Sometimes you can just put bigger carbs on the same stock bike and it will go faster...

I was making some needed changes to my bst36ss's only to realize I rounded off the head of one of the pilots. Well it just so happens I have a 750m parts bike in my garage. So this kindof got changed from a backburner "some day i'll try it" idea to a necessity overnight.

Edited May 11, 2016 by boilerdude

[boilerdude]

Then sometimes theres other factors like for example canadian gsxr 1100w had 40mm carbs but here in US we still got stuck with 36s. While even our 750 still had 38s. But its the same engine. Same valve settings. It's just waiting for you to find a set of 40mm canadian model carbs to be put on.

Basically just because the bandit (which is a budget bike btw... built well but cheap...) came with 36 doesn't mean those are the absolute optimum carbs for the bike

Edited May 11, 2016 by boilerdude

[boilerdude]

how the hell do you even get the airbox out of a 750m anyway...

Edited May 12, 2016 by boilerdude

[Captain Chaos]

3 hours ago, boilerdude said:

how the hell do you even get the airbox out of a 750m anyway...

remove tank + fairings, remove carbs, intake rubbers and generator. Gives just enough space to remove the airbox from the left side.

[boilerdude]

Ok so far there has been..

a minor re routing of the spark plug wires to make the little black filtery box thingy fit. #2 and #4 wire are now over the throttle cable. There is only one throttle cable now...

I'm pretty sure I need the pet cock off of the gsxr 750. Edit: NO IT DOES NOT FIT!!! The bandit one hits against the #2 diaphragm cap (These carbs are taller).  pet cock rests on the diaphragm lid just before you can bolt it in.

The fuel hoses do not fit just in front of the k&ns. You have to either squeeze them in behind the brace thingy or get longer ones and run them all the way down around the filters.

Edited May 15, 2016 by boilerdude

[boilerdude]

Ok so the gsxr pet cock does not fit the tank. I need a new low profile pet cock for my bandit tank. Preferably one that is still vacuum operated so it works all nice and stock like...

Disregard this post... I figured that shit out. It's on the first post.

Edited June 1, 2016 by boilerdude

[boilerdude]

pet cock

[boilerdude]

On 5/11/2016 at 6:56 AM, Venom said:

because 38s works much better and you can achieve  more HP . I have 38mm in my B12 and I will never back to 36 mm.

 

What did you do about the pet cock issue.

[Gixer1460]

On 5/11/2016 at 2:59 PM, boilerdude said:

Basically just because the bandit (which is a budget bike btw... built well but cheap...) came with 36 doesn't mean those are the absolute optimum carbs for the bike

I never said they were optimal but have yet to find anyone who could use all the performance from bigger carbs DAY 2 DAY against the smaller ones! My 1460 has 185hp with 46mm EFI but also works with 40mm RS flatslides - probably 170hp - but the 40's produces soooo much more torque that can be used DAY 2 DAY they work better! A M8 had 41mm FCRs on his 1216 bandit (which engine wise was mostly GSXR, only bandit cases) and made great power but likes the RS36's fitted now better cos they make nearly the same power @ WOT but out torque the bigger carbs by miles in the mid range!

[boilerdude]

I dont care if its peaky. I want more peak horsepower. Cuz I'm a MAYUHN!!!

 

        

Also those examples you cited were both 5 or 6 mm of difference you guys were swapping between... I'm just fitting bst38s instead of 36s. Just a wee bit bigger. I bet it's still plenty rideable (several people saying they work great). Soon enough I'm going to try the stock intake stacks with ramair filter setup. I hear that works much better than pods. Restore some of that response. 

Edited May 15, 2016 by boilerdude

[boilerdude]

Sorry I didn't mean to be abrasive with that whole schtick. Just jokin around. Anyway I have the gsxr parts bike sitting around anyway. Figured it's worth a try. And then another try with the stacks and ramair filters. 

I'm having fun swapping them over making them fit. I actually got to grind something with my bench grinder I forgot I had. 

Edited May 15, 2016 by boilerdude

[Gixer1460]

No offence taken, I just feel for peeps who go chasing bar room horsepower that is impractical in use but your train set so knock yourself out.

[boilerdude]

you really think they're gonna be that bad? 

[Captain Chaos]

I put 38's on my B12 engine because it was all I had at the time (36's were on a friend's bike). And I found out that it ran pretty well with the 38's so I kept them. No very big difference but still noticeably faster.

Now by the way the 38's are on my Powerscreen engine and the B12 has its 36's again.

 

[boilerdude]

Yea. noticeably faster. Thats what I'm talkin about. lol.