I feel like I’m writing this every time I post here, and if I take a look back and check, it’s probably the case! But anyways, it has been a very long time since my last post, and a lot of things happened since then.

First of all, I broke the Mikuni RS carburettors which I had some problems with. I had to be a smart-ass and turn the pilot screws with a screw-driver when I had the carbs off the bike, and that way had no feeling whatsoever with the amount of torque given to the pilot screw nozzle in the carburettor housing. So, the tip of the pilot screws got penetrated into the carburettor housing and broke off from the screws. The hole in the housing are even larger now, so there are no way to make these run perfect.

So, I decided to buy a new set of Mikuni RS34’s, and so I did. Just $ 1000 out the window, sometimes getting experience turn out rather expensive, when you have to learn the hard way.

Anyways, I got the new set of carburettors, and a new set of jet needles. The bike runs much stronger in midrange and low-end now, with the engine sounding much more satisfied with fuel. For the record, the needles I am using are 9DZH04 (measures Ø 2.48mm). I will make a diagram with the jetting parts some time.

I have gotten a new stainless 4-1 Cobra exhaust system (the one with upswept middle pipe) with stainless cannister. I was really amazed by this system, and I think that this is by far the best looking exhaust system you can find for reasonable money for these bikes. I have no idea about the performance yet. This exhaust system came with a db-killer/silencer that are good for long road trips, I had a lot of trouble getting this thing out of
the cannister. It seemed that the trick was to unmount the cannister and press a waterpipe through the exhaust from the middle-pipe side, and BAM it was out the very instant, with no force needed.

I have discovered that my front light and instruments are making a lot of ratchet noises, not as much as the flatslide carburettors, but this is really annoying. This is nothing that new rubbermounts will be able to fix.

So, last night, I decided to buy a new set of instruments for my bike. I have chosen a set of Koso RX1N with white backlight, because of the posibilities, the looks and the low price compared to other instruments around.

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It has been a long time since last update, again. The project has been standing still for about a month now, wether I can blame lack of motivation or lack of funds, I don’t know. Probably both.

I have a major issue with the bike, that I have to sort out before I can “ride” it for real.
This is for all of you Mikuni geeks out there! my knowledge is very limited when it comes to carburettors,
which also scared me a bit when I were thinking about purchasing the Mikuni RS34 carbs. Team d’Or told me that it was pre jetted to a Honda CB900F with the 985cc Wiseco big bore kit, but it would most probably require some fine tuning to my specific application.
The problem is, that the fuel mixture is too lean in the midrange, 1/4 -> 3/4 throttle. First off I thought I could adjust my way out of it, by moving the needle clip a couple of positions downwards, trying with one at a time of course.
Now the needle clip is in the lowest position, and I’ve still got a lean running engine. I had my bike dyno’ed some weeks ago, and the guy told me that I would have to get a 20 percent thinner needle, (huh? I thought they went in smaller steps?).
I have tried to figure out the Sudco online catalogue to find out which needle I would need for replacement, but it seems that I’m already running the thinnest needle made for my carbs.

So, perhaps I can resolve this problem by changing the needle jet, by getting a set of needle jets with larger inner diameters. Any thoughts?

My carb setup are as follows:

It has been a long time since my last post, my server has been down and I have not been able to recieve e-mails at the address stated on this site. I have been up to a lot with my bike since my last post in January, basicly the engine is put together and running now.

I bought a set a Wiseco 985cc 10,25:1 compression, forged piston kit and had the cylinders rebored by 3mm Ø. The motor has been put together with the new main and big-end bearings. As goes for the top end, I have regrinded the valves against the valve seats with some “valve paste” to make them seal properly, all of the exhaust valves were covered in carbon.

I recieved a set of Mikuni RS34 Flatslides from Team d’Or, and bought four K&N Pod filters (RC-0981).

Last week I finally recieved my new Dynatek Dyna 2000 ignition with Dynatek 2.2 Ohm coils and 8mm suppression core ignition wires, I bought it from Z1 Enterprises in the U.S., best price I could find on a new Dyna ignition with coils, and impressive fast shipping.

Okay, finally picked the engine up from glass blasting. So finally I can get started on the slow boring process of unwrapping duct tape from the casing and cleaning up the horrible mess, I’d rather spend too much time cleaning up the casing than too little - this is where it pays to be patient and do your best, if not the glass/aluminum grit will kill the engine, once started.

Okay, I usually don’t shoot pictuers without flash, but I just couldn’t bring out the details on this picture without it. So bear with me. I have taken the liberty of removing some of the duct tape already, to see wether the gasket surfaces were hurt or not. No problems found yet, so it all looks good.

Hurray! I called the company that was supposed to glass bead my engine casing and it seemed that it has been ready for a while, although they never called me? - Hmm no big deal, I’m going to pick it up in the morning, as soon as I find someone that can help me with the transportation, the alternative could be a taxi.
I’ll post some pictures of the result as soon as I get home. I can’t wait to get started on this.

Hey, I’ve got some good news this time. I have been wondering a lot on how to figure out the connecting rod bearing color codes, because I really couldn’t make up the indications on the crank shaft. Anyways, I opened the rods to look at the bearing conditions, the half shell bearings for connecting rod #1 and #4 looked OK, with no scratches whatsoever. But number #2 and #3 both had some minor scratches, they didn’t look as bad as the main bearings but I’m glad I took them apart to check them anyways.

I tried measuring the current con rod bearings with plastigauge to find out if the oil clearence was out of spec, just as I did with the crank shaft main bearings. To my luck, all of the bearings were still into spec, dispite the wear on #2 and #3. When reading the original workshop manual, just one more time. I noticed a little picture that indicated the bearing color codes on the bearing itself. Those color codes were gone on the main bearings, but I gave it a shot on the big end bearings. And thankfully, there was still a thin layer of brown color, on the side of each bearing.

So, I hurried in to my computer and placed an order on 8 big end bearings at David Silver Spares. Delivery time was 7-14 days, gees. The thing I’ve come to know about David Silver Spares, is that they always tend to exadurate delivery times, so, I might be lucky having the new bearings next week.

No updates on the project, I’m still waiting for the engine block to return from the glass blasting process. I thought it was something you just delivered and they’d prepare it to the next day or something.

I guess I was wrong.

I promised to do a writeup on main bearings, including a scheme on how to determine the correct replacement bearings. So here goes.

To find the correct replacement bearing color code, you have to read the color codes on the rear right end of the upper crank case half. There should be a reading of five color codes - mine was “B B B B B”, then you’ll have your case inner diameter code no.
The main journal outer diameter code no. is located on each crank weight. They can be pretty hard to spot as they go easily off from wear inside the engine. I took a high resolution picture with my camera and post processed it to highlight the almost worn off color code. My crank main journal outer diameter color codes were as follows, from left to right seen from the above - “A B B B A”. And as all the bearings were still into specs, I could directly find the replacement main bearing from the above scheme. Which made me end up with “C B B B C”.

I hope somebody out there could use this small guide, if you have questions or any corrections to the above method, please post a comment and I’ll see what I can do.

A couple of days ago I received a set of Honda genuine spare parts that I ordered. The package contained new main bearings with the color codes I determined in my last blog entry, I’ll post some schemes later on how to determine the correct main bearing color codes. I also got a new primary and cam chain, and a set of oil seals that I need to assemble the engine block.

I have prepared the engine case, cylinder and cylinder head for glass blasting, so I’ll have a completely clean engine casing before applying the new engine paint. I’ve used duct tape to cover the parts of the engine casing that I did not want to get blasted, and used some “dummy” screws to cover up exposed threads.

And of course, merry christmas!

It has been a while since last post now, so I’ll just bring some updates on what progress I’ve made so far. I got the crank case open after spending one and a half an hour with a wooden plank and a hammer, trying to pry the engine cases from eachother with the plank. After opening the engine, I started tearing it down from the inside. I started out by removing the primary shaft, primary chain, cam chain, crankshaft and then the rest of the gearbox.

So I decided just to head on to measuring the old bearings, which I was adviced not to reuse. This was the part of the engine rebuild that frightened me the most. I had bought some plastigauges some days before, which I used to determine the main journal oil clearance with. By putting a bit of plastigague on each crank journal, putting the crankcase back together and tighten it up. Then off again, and you can go right ahead measure the compressed plastigauges. As in the picture. My bearings were far from out of spec, so I’ve ordered an identical new set. You will have to determine which bearings that the engine came from, by comparing the color codes on the top rear on the case, and the color codes on the crank shaft.