My first FJ1100 had RS-36 carbs and it ran great with those carbs. The carbs were the old versions with bakeolite plastic slides and they started to have a hanging idle problem I couldnt fix so I bought a set of RS-38 carbs. I didn't get much if any improvement over the 36 mm carbs in HP with the stock 1100 engine and the larger carbs didn,t run as smoothly .When I put The larger 1249 cc engine in with the RS-38 carbs they seemed like a perfect fit and the bike runs very smooth.I think the RS-36 carbs would be a better fit with a stock 1100 engine.

I was actually looking at doing Mikuni RS36 carb's in place of my torched BS36's that came on the bike. Do you actually need to go to the 38 size, in leu of the 36's, to get it to be more plug and play? I do intend to go with the Wiseco 77mm piston's in the future but haven't done that change yet, so still running stock piston and rings.

I love the RS-38 carbs. My bike runs smooth from 2500 all the way up through 9500 rpm. The bike had loads of power with the 1100 engine and the RS-38's now that I have the 1249cc xjr1300 engine in the bike with the RS carbs this bike really runs strong. My son has a zzr1200 which is a rocketship but when he rides mine he notices the extra snap when you roll on the throttle due to the accelerator pumps. On a side by side roll on my FJ will pull away from him until his cv carbs catch up.This spring we are going to do a side by side 1/3 mile run down the alpine county air strip to see how they compare. I doubt I can beat his bike but I don't think he will be leaving me in the dust. He was hitting 156 mph on his runs a few years back despite being at an altitude of 5,900 feet. One of the guys in our group who was riding his fjr1300 was dissapointed that his bike was only getting up to 145 mph .
 The RS-38 carbs are easy to tune. Ive found the suggested settings on the mikuni spec sheets were right on the money except the pilot screw settings. The specs say to set the pilot screw to 1/4 to 1/2 turn out. The carbs will run very lean and rough at those settings. I have my pilot screws at 1-3/4 turns and it runs very smooth. The accelerator pump needs to be set to start at 1/4 throttle and end at 3/4 throttle or you can get a stumble at about 5,200 rpm.It is also important to have the carbs balanced. One other consideration is to make sure the accelerator pump nozzles are turned correctly to spray down the carb center.

The Mikuni TMR flat slides would be my choice. They have rollers on the slides.
https://www.ebay.com/itm/116885339938

They do have a unique jingle jingle jingle as roll down the road.

Quote from: Pat Conlon on Yesterday at 06:48:56 PMYes, the Mikuni RS38's are common. IIRC Travis is running a set on his FJ.

I have my 86 engine rebuilt with 1219 Wiseco's and 38 MIKUNIS on it. Started today first time.....Mozart sound....

Yes, the Mikuni RS38's are common. IIRC Travis is running a set on his FJ.

Quote from: fj1289 on December 06, 2020, 10:12:57 AMAnother option - but not CV's (at least I don't so) - some GSXRs came with flat slides from the factory.   They may be a bit more well behaved - but will be very hard to find!

Sounds like you would really like the roller slides of the Keihin FCRs -  really smooth compared to the Mikuni flat slides. 

Here you go: Mikuni flats 38mm

Quote from: ajacstern on May 27, 2022, 01:58:21 PMHello all,

Hope everyone is doing well. Over the winter I decided to convert my '87 FJ1200 to 17" front and rears. So far I have only converted the rear as I wanted to get a feel for the difference each individual change made. I used a 93-97 gsxr1100w rear wheel (I believe) and a 180/55/17 Dunlop Roadsmart 4. 38f/42r psi. For the brake I wanted to keep the original mounting point so I used a GSX750F Katana rear caliper and torque arm, had to hammer the torque arm a little for clearance but it bolted right up after that. Unfortunately, removal of the rear wheel now requires removal of the caliper as well, not sure if that is the same with the underslung, if not then I may switch to the underslung after all.

I went out for a test ride and at first it felt great. Tire heated up very fast, quite sticky, feedback and compliance felt good. On low speed turns the bike felt like it wanted to fall into them and you had to turn the bars the other way to keep the bike up, but it wasn't crazy bad given I don't do Motogymkhana. Once you got to 20-25mph the handling feels absolutely perfect. However, at high speeds (55mph+) the handling is incredibly stiff, takes your whole body weight to switch lanes quickly. This problem was present with the old wheels too and is the main reason I switched, though it feels a little bit worse now. I am hopeful that switching to a late model front wheel and raising the forks will fix this.

The biggest two new problems come in the braking department. I tried to trailbrake a little bit and the bike violently shot upright, much more than it has ever done before. It used to be fairly accepting of trail braking but now it is barely possible to turn and brake at the same time, this is using the front brake. I don't know if this is because of the wider rear, 0.3" lower rear ride height, or switch to radial tires. Has anyone had this and found a fix? It is bad enough that I would go back to the 16"s which I really don't want to do. The other issue is that this rear brake is barely a suggestion. It is functional, but even if I stand on it with my heel it can't lock up the rear and barely slows the bike down. If that is somewhat normal I will switch to sintered pads but don't want to throw money when the caliper is simply not up to the task...

Thank you!

So FZR 1000 87/88 front wheel fits 86/87 forks set up?
I have 86 with progressive springs, just rebuild and anti-dice plate and wondering if I can put FZR rim straight on it.

Thanks 

I am in the middle of de-rusting and repainting the silver portion (front) of the frame on my 1985 FJ-1100 and I am planning the next phase of the project, which is cleaning and repainting the engine.  From the earlier posted photos you can see that the only solid black areas that have survived on the engine are the valve cover, the area beneath the fins, and the area around the gearbox, and those are very weathered.

While I appreciate the visual aesthetics of black painted fins and bare aluminum edges, does painting the fins adversely affect air cooling on the early FJ's?  I am inclined to do whatever is best for the longevity of the engine.

What are the alternatives to re-painting the fins black?

Can the exterior engine be successfully restored while it is in the frame, or is it necessary/best to remove the engine before repainting it?  The bike has been largely disassembled, but I have not removed the engine up to now.

Thanks for sharing your experiences and suggestions!

Steve

     

Quote from: RPM - Robert on Yesterday at 10:35:03 AMCorrect on the 86/87 model it should not flow any fuel until vacuum is applied. If it is flowing fuel the petcock is bad.

The 84-85 has a prime function which will flow fuel when the selector switch is in the prime position but in the on position it should not flow fuel until vacuum is applied.

Thank you Robert.