Gsx 1100 efe engine tuning advice

[Coleman]

Hi all I’m new to this forum and have just bought an old gsx 1100 efe from 86. The motor is in good shape although it has 61000km on it, the rest of the bike is fairly worn out but road worthy. So my question is , I’d like to tune the motor but what would be considered a good  fast road tune ie what components would give best value for money against power gained. Any advice is much appreciated. Thanks nick

[Captain Chaos]

Hi and welcome to OSS. Post some pics of your EFE. We like pics, pics are good.

 

16 minutes ago, Coleman said:

best value for money against power gained

install an oilcooled engine.

 

 

[TonyGee]

your gona need deep pockets  also bigger wheels & tyres, better suspension and brakes. 

[Joseph]

It's fast enough as it is.

Spend your money on K generation GSXR forks, rims, brakes and a decent shock

You may find the performance of the bike will be greatly improved for less money than cams, pistons, bearings etc

[Coleman]

Thanks for the words of wisdom, I forgot to mention I have a mk2 1200 bandit swing arm and back wheel and I was wondering about a front end which doesn’t require a huge amount of engineering to get it in , maybe just a new steering stem .

[Coleman]

the body works a bit tatty and the forks are weeping also oddly enough it stinks like an old electric radiator that’s just been started after the summers over. No electrical gremlins though.

[TonyGee]

1200 bandit front ends are popular just a stem swap and sort lock stops, or if you can find a good set !!!  the gsxr1100 front end is good. 

mines got a bandit swinger and wheels, and the 1100 forks.  

 

[Swiss Toni]

Nice bike. Lots of potential. Welcome to OSS. 

[Fazz711]

Nice project. 

They will have you fitting a turbo in no time lil

[Arttu]

1 hour ago, Fazz711 said:

They will have you fitting a turbo in no time lil

Well, a turbo is probably one of most cost effective ways to tune these Yes, it costs quite a lot money to fit one but $$$/hp will be hard to beat.

For low cost tuning options I guess the first one is fitting some good exhaust, maybe more free flowing air filter and tuning the carbs to suit. No idea how big improvements these will give on an EFE but I guess it should be something noticeable. Beyond that it starts to get expensive. Bigger pistons with big block, head porting with bigger valves, hotter cams, bigger carbs and so on. At some point the bottom end start to need attention too if you want it to be reliable. Clutch basket needs reinforcement pretty soon although this is more like a maintenance job since it will get loose at some point even with stock engine. Crank rebuild is highly recommended if you want to rev it higher or get big power otherwise. That's fairly expensive specialist job and the specialists are rare these days.

[bitzz]

Start with the basics. You've got a 36 year old bike with a fair amount of mileage.

Start with a compression test and a leak down test... if the rings or valves are sacked you wasting valuable beer drinkin time and monies. Check the oil pressure.

If that all checks out, tune the motor and leave it alone. You might want to get rid of the CV carbs.

Your time and money are better spent on suspension.

You can get all the adjustment that a modern fork has by dropping in a cartridge kit from someone like Maxton. It is probably the cheapest, easiest way. Might not LOOK as spiffy, but it WORKS.

[denisd]

Bet you're sorry you asked now! 

Welcome to the asylum lad. 

[Dezza]

The efe doesn't exacly have a good reputation for handling well, even when new. The basic suspension, 16 inch front wheel and shear bulk of the thing all adds up to produce something that can get a bit wayward at even moderate speeds. Worn suspension components and roads that are poorly surfaced and full of potholes aren't going to help either. Changing the suspension, wheels and brakes will go a long way here, as will changing the stock exhaust, which weighs several tonnes. +1 also for doing the basics on the engine such as a compression test.

[Rampe]

Mikuni RS flat slide carbs aren't horribly expensive as new, you get rapid throttle response and some extra tunes to sounds too. And getting rid of old worn out stock carbs is always a safe bet. 

EF 1135 engine is rather good for low boost "stage 1" turbo usage, since you basically only need a cylinder block spacer plate to lower compression and Dyna S (or similar) to ensure spark. I would also use APE studs for rebuild, not that expensive addition. Plus the turbosystem ofcourse  Stock pistons are forged and some of the crank pins are welded from factory, unlike in early 1100 models. Like Arttu already mentioned, the clutch basket should be reinforced in any case.

[cnap504]

Brakes, tires, suspension.  Less restrictive exhaust and tune the carbs, if retaining original air box carbs would probably only need fuel screw richening, needle shimming and may be a bit more main.

[baldrick]

if it was mine id go 1230 bore kit, freshen up/clean up the head/valves intake. new stem seals while youre in there.

a set of 36mikuni flat slides and a decent free flowing exhaust.

check the clutch backplate.

 

then a decent set of forks and wheels /suspension and its ready to rock.

[Coleman]

Thanks for all the advice, I’ve gone and bought a set of mikuni rs36 and a 1230 big bore kit also a bandit swingarm and wheel , on order is the complete front end from a gsxr 1100wn , I ordered an exhaust about a month ago and I’m still waiting for that . Next up is the clutch which is a bit of a mystery as to what to get, so I’ve got a few things to be getting on with this winter. Maybe some Kent cams but I have no idea as to if it’s worth it or not.

Edited August 12, 2022 by Coleman

[Duckndive]

Besides a Turbo its a 

[Rampe]

4 hours ago, Coleman said:

Maybe some Kent cams but I have no idea as to if it’s worth it or not.

I have the US model D-marked "124hp" cams, which are mentioned at other topic here. Worth checking if you could get them for reasonable price, I like how my otherwise stock 1135 behaves with 'em and RS36's, always ready for revs and roarrrr.