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General Category => FJ Project Writeups => Topic started by: Troyskie on May 13, 2025, 06:17:34 AM

Title: 85 1100 gets 4AY 1200 motor with wild cams and Mikuni 38mm flat slides
Post by: Troyskie on May 13, 2025, 06:17:34 AM
Well FJOwners I've been lurking, just not posting  (popcorn) .

The project bike concerned is my brothers 85 1100 purchased back in 97.

Here's what we know if it's provenance.
Originally purchased in 85 out of Townsville QLD Oz in 85. Was rented out of Cairns till written off by 'Japanese tourist' (well at least the FJ beat the crocs :) ). Rebuilt and found its way to Perth Western Australia, where it was bought by my bro Mark.

By some quirk of fate I was the first to ride it. In reality we flattened the battery trying to start it and I happened to be the lucky chap taking a break from pushing and was in the saddle when it finally fired up.
A 100m round trip back to Mark was my first ever FJ riding experience.

From memory it only had around 15k on the ODO.

Over 600,000ks and nearly 38 years later this project begins.
But it is not nearly the first work on the bike.

Here's a summary:

Here's some pics of Marks fun with the bike from the 80s & 90s. The clear photo of effie in the garage is showing him sleeping for 7 or 8 years
Title: Re: 85 1100 gets 4AY 1200 motor with wild cams and Mikuni 38mm flat slides
Post by: Troyskie on May 13, 2025, 06:41:11 AM
Allrighty that's the intro.

What am I doing?

Well, this is a sentimental project with a bike I've ridden for almost 38 years.
It will be turned into a track bike that is road registered, and somewhat period correct (thinking about USD forks here :) ).

So, here we go.
A mate of mine, Gav, another Oz member, found himself flying through the air when he last thought he was riding his 4AY 1200.
After the ground rudely interrupted his flight he found that consciousness, a spleen, some other skeletal continuity, riding buddies and a motorcycle were suddenly absent.

Gav and his bike had unintentionally joined the "it was at that moment" brigade. A short flight down a 10m rocky embankment over the armco to amazingly land and not splat on the fucking pointed rocks all around. Really  really lucky.

Gav still rides and donated his FJ to the local community, of which I'm one & now I can add his history to Marks.

Gavs' bike has a genuine 120HP at the back wheel. I was there at the dyno run and can probably get a graph. I might have posted it here as well......(Pat, any idea?)

I can't remember what Marks engine had, but compression was good, but a tad low for Wiseco HP.
However, this bike has been both Marks and my main transport for almost 38 years on and off.
Time for a change, and Gav's mishap is our opportunity.

Title: Re: 85 1100 gets 4AY 1200 motor with wild cams and Mikuni 38mm flat slides
Post by: Troyskie on May 13, 2025, 06:49:25 AM
Here we go, strip down. Day 1.
Title: Re: 85 1100 gets 4AY 1200 motor with wild cams and Mikuni 38mm flat slides
Post by: Troyskie on May 13, 2025, 08:36:49 AM
Day 2. We're taking our time ok? :sarcastic:

Every second bolt, nut or screw strips.
It's like losing the will to live.
I LOVE this project!!!!! As I realise I remember this what I think throughout every every Fj project.

The cam swap was pretty straight forward.
It was much helped by Pete's competence and experience.

Some years ago I was fortunately able to purchase two sets of complete FJ screw, nut, bolt and washer set from wreckers out of Japan.
They literally arrived in the post in one bag for each bike but all mixed together.
My kids still remember fathers day one year sitting in the shed with dad sorting the mess into like piles.
I really love being able to go to my FJ stores and being able to find an exact nut, bolt, screw, even washer or weird damper that came in those bags.
Those bags of bits truly made this mini project so much easier. Please Japan, for what ever reason you stopped, please wreck bikes with the components together again.

Anywhoo, now to really getting frustrated.

Fucking cams!!!!!!!!!

Ok, it's me, not the cams, or the tools (Troy you're such a tool!!!!!!!), it is me.

Pete and I spent hours doing the shims. Knock off, sleep on the project and hook in the next morning. The shim measurements are different and not by possible error, waaaaaaaaaaaaaay out.
What's wrong?
Is it our fault? (YES :) )
What did we do wrong? I'm not sure but I think it's called beer.

Those fucking cams! As the cams were welded they are substantially wider than standard.
As they're wider they push the cam bucket tool away from the edge of the cam bucket.

We had to modify the shim tool that holds down bucket to suit modified cams.
The modification was simple. When the tool is used on standard cams a light witness mark is left on  the casting surface.
Essentially the cam lobe was wider and needed more clearance, so we used my Dremel thingy to make it work by careful grinding away and smoothing around the witness mark on the shim tool creating more clearance between the cam lobes and the cam shim tool.
This worked and we were able to finish putting the motor together.

I'll not bother with the valve cover or other simple things.

Getting the motor in without scratch was impossible for us.

It went in and we did the job, but it was not as neat at we thought or you would like.

Because I chose to not remove the forks or subframe I made the job much harder and trickier.

Pete Jono and myself wiggled, lifted and worried effie onto the frame.

We've learnt a few lessons along the way that you are probably laughing about right now
Title: Re: 85 1100 gets 4AY 1200 motor with wild cams and Mikuni 38mm flat slides
Post by: Troyskie on May 13, 2025, 09:38:00 AM
Here's some pics
Title: Re: 85 1100 gets 4AY 1200 motor with wild cams and Mikuni 38mm flat slides
Post by: fj1289 on May 13, 2025, 10:19:26 AM
I love these type of projects - keeping a loved bike on the road and making it even better!




But ... the Effie naked 28 picture NEEDS an epic Klavdy post and picture in response!
Title: Re: 85 1100 gets 4AY 1200 motor with wild cams and Mikuni 38mm flat slides
Post by: Waiex191 on May 13, 2025, 11:09:10 AM
That's really awesome Troyskie!
Title: Re: 85 1100 gets 4AY 1200 motor with wild cams and Mikuni 38mm flat slides
Post by: T Legg on May 13, 2025, 12:54:16 PM
I'm ignorant Troy. What's a 4AY 1200 engine out of ?
Title: Re: 85 1100 gets 4AY 1200 motor with wild cams and Mikuni 38mm flat slides
Post by: Troyskie on May 13, 2025, 05:51:57 PM
The 4AY is a FJ1200B that first entered production in 1991 and is basically one of the last variants to be produced. There were still a number of 4 series variants developed between 91 & 95, however the very last variant produced in 1995 was the 4AY, with about 900 made. These were sent to 'Oceania', which I assume means mostly Oz and NZ, however I did see a later model FJ in Fiji once.
Title: Re: 85 1100 gets 4AY 1200 motor with wild cams and Mikuni 38mm flat slides
Post by: T Legg on May 13, 2025, 06:23:26 PM
How did you handle the difference in the bottom rear engine mounts?
 I just finished putting an engine from an xjr1300 in my black 84 FJ1100. I couldn't find a machine shop that would drill the holes to fit the larger mounting bushings so I had to drill the holes out myself.
Title: Re: 85 1100 gets 4AY 1200 motor with wild cams and Mikuni 38mm flat slides
Post by: Billy Bananahead on May 14, 2025, 01:29:25 AM
Quote from: T Legg on May 13, 2025, 06:23:26 PMHow did you handle the difference in the bottom rear engine mounts?
 I just finished putting an engine from an xjr1300 in my black 84 FJ1100. I couldn't find a machine shop that would drill the holes to fit the larger mounting bushings so I had to drill the holes out myself.

I've put an XJR1200 engine in my 3CV and just left that mounting point you're on about empty.
It doesn't seem to make any difference as to whether the torque from the engine pulls it to the side, it is held solid.
Title: Re: 85 1100 gets 4AY 1200 motor with wild cams and Mikuni 38mm flat slides
Post by: Troyskie on May 14, 2025, 04:49:32 AM
We didn't do anything on the rear at all Travis, it slipped in like a banana on stage. But we did um-and-ah as another Oz member did the same thing and had the same issue as you.
Perhaps the 4AY motor being an early bird, this one is VIN # ...204, makes some difference?

I thought my bro had replaced the bottom half of the case with a later model as the lower frame rails are 1200, but when I asked he said it was the top, but that doesn't make sense as the engine # is the same and not 're-stamped'  :biggrin: .
Title: Re: 85 1100 gets 4AY 1200 motor with wild cams and Mikuni 38mm flat slides
Post by: Troyskie on May 14, 2025, 05:22:33 AM
Day 3.

I missed the final part of day 2 which was to run the engine with the new cams before cracking on with the rest of the assembly. Here's a link to the vid. https://youtu.be/D1URj6RKUB0 I've made it private, so let me know if you can't access it I'm still pretty unfamiliar with publishing on YT.

Now that we had the motivation of a runner in the frame it was time for dinner, drinkies, fire and tall stories  :sarcastic: .
Now day 3 actually starts.

I had an excellent time on the Gerni removing 30 years and over 300,000ks of chain lube, road grime, bits and pieces of who knows what from the rear wheel, chain guard, shock, dog-bones and that cool swingarm.

Whilst Pete and Jono dealt with the wiring shit-fuckery and relay shenanigans I popped the swingarm, shock, and other bits in with Pete & Jono helping on the footpeg plates.

The clutch slave had a little spasm and decided to lock-up. It was a very new OEM one, but luckily my FJ stores came to the rescue again and we had a slave rebuild kit ready to go. None of us had ever refurbed a slave successfully before, but with the support of copious beer we somehow got it right, re-assembled, installed, bled and working (kinda :) but more about that later).

I've never had to deal with the type of swingarm rear wheel adjuster like this JMC one before. The axel was different, and I stupidly pulled it apart without taking photos or notes so re-assembly was put off in favour of continuing with all the other things we needed to to get the bike road ready and left the rear wheel for later.

As you can imagine there was lots of fiddly bits and awkward moments but with a couple of mates who know their way around and FJ it was all pretty fun.

Pics below
Title: Re: 85 1100 gets 4AY 1200 motor with wild cams and Mikuni 38mm flat slides
Post by: T Legg on May 14, 2025, 09:55:03 PM
Quote from: Troyskie on May 14, 2025, 04:49:32 AMWe didn't do anything on the rear at all Travis, it slipped in like a banana on stage. But we did um-and-ah as another Oz member did the same thing and had the same issue as you.
Perhaps the 4AY motor being an early bird, this one is VIN # ...204, makes some difference?

I thought my bro had replaced the bottom half of the case with a later model as the lower frame rails are 1200, but when I asked he said it was the top, but that doesn't make sense as the engine # is the same and not 're-stamped' 

 The hole in the bottom rear engine mounts of the xjr engine and I think the 89 and later fj rubber mounted engines are about 13 mm and the holes in the fj1100 and early fj1200 are 28 mm. I drilled mine out to 28 mm. Maybe your engine was already drilled out
Title: Re: 85 1100 gets 4AY 1200 motor with wild cams and Mikuni 38mm flat slides
Post by: T Legg on May 14, 2025, 09:57:34 PM
Before and after drilling.
Title: Re: 85 1100 gets 4AY 1200 motor with wild cams and Mikuni 38mm flat slides
Post by: Sparky84 on May 15, 2025, 05:18:06 PM
Quote from: Troyskie on May 14, 2025, 05:22:33 AMAs you can imagine there was lots of fiddly bits and awkward moments but with a couple of mates who know their way around and FJ it was all pretty fun.

Pics below

Looking good there and sounding even better, looked like an impromptu mini manshed weekend and you got a lot done.

Next one you have I might drop in to sort out my vacuum leak causing "hanging idle" which I haven't fixed yet.

And tell Johno to leave your chooks alone 
Title: Re: 85 1100 gets 4AY 1200 motor with wild cams and Mikuni 38mm flat slides
Post by: Troyskie on May 18, 2025, 02:54:03 AM
I think you're right mate, it was likely an early 1200 bottom case.
Title: Re: 85 1100 gets 4AY 1200 motor with wild cams and Mikuni 38mm flat slides
Post by: Troyskie on May 18, 2025, 02:57:19 AM
Thanks Al! It was a kind of mini shed weekend.

I'll post up the rest soon. I'm also trying to book the dyno this week to see if what we've done has woken up Gavs motor even more than the 120 rear wheel HP from his last dyno check.
Title: Re: 85 1100 gets 4AY 1200 motor with wild cams and Mikuni 38mm flat slides
Post by: Troyskie on May 18, 2025, 07:14:36 AM
Day 3.1 or 4, take your pick.

It is a short day as I have a few meetings this morning & Pete has a date with a skinny dog heading to Bermie around lunchtime.

Effie still requires a rear wheel and some other bits and pieces. My wife requires 'her' part of the shed at lunch for a 'client' so we need to be finished by around 11am, hence day 3.1, even though it is really #4.

As I've had morning meetings, Pete & I have lost a good couple of hours so it is a bit of a rush (isn't it always  :pardon: ).
However, the roller door opens, the Tiger gets pushed out of the way and we begin the process of removing Effie from his hoist.

After scaring the shit out of myself and Pete by incompetently backing the bike off the hoist Effie is on the apron and ready to run.

I throw the last of the good fuel from one of my jerries in Effies tank and Pete does the honours flashing Effie to life.

CRAP, running on 3 cylinders, hard to start, FUCK I think, what has changed since the we flashed it up last? It ran so well and start literally first crank!!!!! FUCK FUCK FUCK!!!!!!

As Pete was doing the start honours, he kept at the choke, blip, rev, choke, rev, blip routine, totally entertaining the neighbours with the symphony of a really flogged out Pipeline 4:1 saying 'GOOD MORNING!' again and again till it ran well.

Woo hoo (but not yet Kookaloo), I'm dashing to the corner to gab my gear. I don't want to leave Effie the air cooled dinosaur idling too long.
A few parting safety reminders from Pete & I decide it would be better if the (not really great) clutch had a little help and Pete pushed me when I pop it into 1st and let the clutch out. Effie puts my concern aside like I'm choir boy worried about a smudge and snicks into gear and holds 1st like its the billionth time it's done it.

Off I go. Not for long and not very far. I can't get into 2nd, but I can get into neutral. Back to the shed I go.

Within about 4 nano seconds Pete has solved the problem.

A simple change of the spline orientation of the gear selector and Effie snicks into 2nd etc. nicely.

Off I go.

Whoah!!!!!!!!!!!

KOOKALOOOOOOOOOOOOOOOOOOOO  :good2:

I live in the country with some long roads. I'm not sure they're long enough to get to top speed now.
As you saw on the early photos these cams look pretty aggressive compared stock with the amount of belly added to them.

Previously, Marks bike in Wiseco 3rd oversize 1100 with 38mm flatslide condition had a very sharp powerband when the cams did their thing.

Now it is much more constant and progressive.

A small problem. I'm not familiar with riding a bike with flatslides. This was a short ride, and decelerating was different and more manual than with CVs, so I didn't really do the bike justice with my throttle control. No biggie, but I could have learnt more about what we've done if I was more familiar with the flatslides.

I ended up running through all the gears up and down to make my self comfortable then gassed it.

STREWTH!!! No front wheel lifting but torque all the way from 2K up. I was not willing to hit the rev limiter as this was a just assembled bike, but I did try to wring it out in 2nd and I ran out of road and courage.
It just kept pulling.

Maybe not Massey Ferguson level torque, but this impressed me.
Admittedly I've not been riding much but a dyno will prove me right or wrong.

I've raided my stores for some nice bits for Effie, new side cover for the RHS that was super faded. New front guard (just one scuff), the 1200 lower cowl that makes an 11 so much better, a new duck tail (new to me), new (NOS OEM) front 36Y smoked screen, and a salvage main fairing and scoops that will be painted to match the rest of the yummy bits so Effie will be back to his shiny niceness.

Interesting point, after over 600,000k's the 'faded' front guard, duck tail, side covers and rear quarters are the originals Mark & I pushed around all those years ago, oh even one mirror.

I test rode Effie naked, here's the idling vid https://www.youtube.com/shorts/9Id1RzDxkVo

Here's some pics..have a look at the close up of the guard. I doubled what Ayhamay say is the 'fork brace' just for laughs as I've got a few. Don't worry, Mark had a proper forkbrace I just haven't put back on yet.
Title: Re: 85 1100 gets 4AY 1200 motor with wild cams and Mikuni 38mm flat slides
Post by: oldktmdude on May 18, 2025, 05:18:38 PM
   Thanks for a great weekend Troy. Getting the FJ up and running was only a small part of the weekend. I really enjoyed the sitting around the fire whilst having a couple of beers and remembering some stories from the past.
Hopefully you can get the dyno test done soon so I can return and do some fine tuning on the carbs and get a test ride in.
Great hospitality as usual mate and it was also great to have Johnno with us for some of the fun.
 Regards, Pete. :drinks:
Title: Re: 85 1100 gets 4AY 1200 motor with wild cams and Mikuni 38mm flat slides
Post by: Troyskie on May 20, 2025, 05:57:49 PM
Good news! I've spoken to Simon at Jobo's and the dyno is booked in for early next week, hopefully Tuesday, but maybe Wednesday.