What else is needed with 1188 Wiseco piston kit?

[Gearbox Paul]

I just purchased a 1985 FJ1100 that has a Wiseco 3mm oversize piston kit installed (77 mm pistons, 1188 cc, 10.25 compression ratio).  This upgrade was done at least 2 owners ago and the fellow I bought it from knew very little about the bike.  When I test rode the bike, it started well cold and hot, idled well, pulled hard and there were no flat spots or hesitation as far as I could tell.  So I bought the bike but I'd still like to know more about it.  Specifically, what else should have been done to the bike when big bore kit was installed?  I found very little information on the Wiseco website, which is surprising to me. 

I assume the stock jetting would have to be changed to accommodate the increased displacement.  I believe the FJ1200 stock jetting is different from the FJ1100 stock jetting but I don't know if that is because of the displacement difference or to satisfy emissions regulations (I read that the 1986 FJ1200 had to comply with more restrictive emissions regs - may or may not be true). 

What about the intake and exhaust?  What mods should be done, if any, to allow the engine to breathe at this higher displacement.  My bike has the OEM exhaust, but that doesn't mean it's right. 

I'm assuming others have done this upgrade and can tell me what else should have been changed at the same time.  Again, the bike runs well so I'm not looking to change anything right away, but I'd like to know what to look for.  Thanks in advance.

[86FJNJ]

How do you know it was an 1188 piston kit and that they didn't go larger?

[Gearbox Paul]

How do you know it was an 1188 piston kit and that they didn't go larger?

I was told that by the fellow who sold me the bike.  He got that information from his mechanic who went over the bike and apparently removed the head to see what had been installed. He gave me the exact Wiseco kit part number.  So I haven't checked it myself but I have to go with what I'm told. 

[86FJNJ]

Ok just asking because the fj1200 jugs say 1188cc on them but people make them 1250cc or even larger.

Do you know if the carbs were changed from the FJ1100 carbs to the FJ1200 carbs? Do you know what jet sizes are in the carbs?

Buy these air filters to flow more air in. They delete the stock airbox. You'll need to buy two. But you will need to modify the carbs to run these so you should decide what you want to change on the exhaust too so the group can make suggestions on carb jetting.

https://www.rpmracingca.com/proddetail.asp?prod=Carb%3ARPMPod&cat=24

Plus the filter oil

https://www.rpmracingca.com/proddetail.asp?prod=Carb%3Afilterspray&cat=24

What state are you in? Carb jetting varies by state (elevation, temp, humidity etc)

[Pat Conlon]

 What else is needed with 1188 Wiseco piston kit?

Nothing is really "needed" the displacement is close to the stock 1200cc that you could run the stock exhaust and airbox and carb jetting and everything would be fine.

However, a favorite saying around here is:
 Old FJ's don't die....because we modify!

Stock FJ jetting on the US models  is lean due to EPA regulations so we fatten things up for a cooler running engine.
From #37.5 pilot jets up to #40.0 or #42.5 pilots.
Shim the needle 1/2 step
From #110 main jets to 112.5 or 115.0 or even 117.5 or #120.0

The biggest modification I recommend on early FJ's is to replace your transmission shift forks with late model FJ forks and back cut the engagement dogs on 2nd gear.

An aftermarket header and UniPods are just frosting on the cake.
UniPods are especially desirable because time will come when you have to R/R your carbs and the UniPods will make the job easier.

A good tune with these mods will get you around 120rwhp.

Cheers

Pat

[Gearbox Paul]

The biggest modification I recommend on early FJ's is to replace your transmission shift forks with late model FJ forks and back cut the engagement dogs on 2nd gear.

Thanks Pat, good info.  Regarding the shift forks/dogs for the 2nd gear, replacing the forks and modifying the engagement dogs is a lot of work and effort.  Other than a test drive, I haven't really ridden the bike yet.  During the test drive, I did not notice any issue with the 2nd gear.  I'll give it more power and put more load on the 2nd gear the next time I ride the bike.  But if it turns out that the 2nd gear works fine, shouldn't I just wait for the issue to occur before tearing into the engine/transmission to fix something that isn't a problem (yet)?  Or am I missing something?   

[Pat Conlon]

Sure, you can wait and see what happens, just don't be surprised.
Depending on how long you plan to keep your bike, if the 2nd gear problem has never been addressed, sooner or later you need to consider it.
Take a quick read:
https://fjowners.com/index.php?topic=666.0

RPM has all the goodies you need
Shift forks and back cut gears:
 http://www.rpmracingca.com/products.asp?cat=39&filter=Shift%20fork

[86FJNJ]

I have an 86FJ I rehabbed, it now runs very well but I have noticed if I get the RPM's high enough in first gear it sometimes goes into neutral not 2nd gear. Had an odd issued when downshifting from 3rd to 2nd as well. Also if I really lay into it it feels like the clutch can't hold the power for a second or so...for me it's not a big issue I just ride normal and it doesn't really happen often. For me it's not a bike I rip around on, it's 39yo so I just enjoy it for what it is, a vintage bike...if I wanted to really rip around on a mean performance machine I could pick up something newer but used for not much money.

[Gearbox Paul]

I have an 86FJ I rehabbed, it now runs very well but I have noticed if I get the RPM's high enough in first gear it sometimes goes into neutral not 2nd gear. Had an odd issued when downshifting from 3rd to 2nd as well. Also if I really lay into it it feels like the clutch can't hold the power for a second or so...for me it's not a big issue I just ride normal and it doesn't really happen often. For me it's not a bike I rip around on, it's 39yo so I just enjoy it for what it is, a vintage bike...if I wanted to really rip around on a mean performance machine I could pick up something newer but used for not much money.

Makes sense to me.

[Gearbox Paul]

Sure, you can wait and see what happens, just don't be surprised.
Depending on how long you plan to keep your bike, if the 2nd gear problem has never been addressed, sooner or later you need to consider it.
Take a quick read:
https://fjowners.com/index.php?topic=666.0

RPM has all the goodies you need
Shift forks and back cut gears:
 http://www.rpmracingca.com/products.asp?cat=39&filter=Shift%20fork

Thanks.  I'll wait for now (assuming I don't have the issue already). 

[86FJNJ]

they are awesome bikes! I really enjoy mine, but my bike before this was a 2007 GSXR750 and that bike had amazing power all through the rev range and only weighed 375 lbs...that was the bike I could (and did) rip on...but this bike, being nearly 600 lbs and nearly 40yo, it's a piece of history to me, still awesome and she can get up and go really well, but riding more on the normal side means less maintenance and repairs for it.

I'm currently saving up for my next bike which will be something newer, fuel injected and still sport touring or maybe ADV. I am seeing early and mid 2000 Kawasaki Concours (ZX14 engine) listed for about $5k, same with some FJR1300's and other similar bikes so I'm on the lookout...

But IMO you should def get the pod airfilters and change your mufflers to something more free flowing and update your carb jetting. My FJ is stock 1200cc, I have the pod air filters and Cobra F1r slipons. 42.5 pilots, HSR needles on 3rd clip from top and 120 main jets and it runs great and sounds great.

What state are you in?

[T Legg]

. Also if I really lay into it it feels like the clutch can't hold the power for a second or so..


[/quote]

that is the classic symptom of a second gear problem. It's not the clutch slipping its the transmission jumping out of gear under hard acceleration then dropping back in. Over time it will get progressively worse happening at lighter and lighter acceleration. It can also begin happeining in third gear. Once it happens you can assume the shift forks have bent as well as the gear locking dogs have begun to round off.

[86FJNJ]

Thanks TLegg didn't know that, I have had it happen in 3rd, was just cruising and layed into the throttle a bit and it felt like power cut out for a second so I thought the clutch was slipping. I'm assuming the engine would need to come out and split the case in order to change those out? Or can that be done just by pulling out the clutch?

[RPM - Robert]

The clutch can be serviced by removing the clutch cover. The cases do not need to be split for this.

[Pat Conlon]

Robert, I suspect his problem is not the clutch, as Travis pointed out, but the transmission. I posted a link above detailing this fix.