My Royal Star - year 2000 technical repairs

[Atslega]

Hello!

I am new member in this forum. This is my first topic, so I hope I will not make large mistakes  If anything, please correct me.

In May 2022 I decided to add in my garage "new" motorcycle Royal Star 1300 (2000y). So far I used Virago 535 (1987y), what is quite small for my body. But overall it is very reliable and comfortable bike.

So in market I found this "new" bike for a very good price. In time of buying I knew, that I will need to change all rubber parts in fuel system, parts in ignition and give carburetors to mechanic, so he changes and regulates everything, whats needed. As it is sometimes with very good and experienced mechanics, work takes long time. So in summer 2022 I did not drive with this bike. In Latvia, where I live normal bike season ends in october. Also for Royal Star 2000 year make some carburetor parts are very rare. In Yamaha they cost very much. From ebay and local after market sellers I needed to send parts three times (even knowing OEM numbers) only then I got almost all, what needed. Still chokes stayed the same (master said, that they will live some while). 

So, when putting all back together I drove back to workshop, so mechanic could switch engine to the engine diagnostic system with gas analyzer and regulate carburetors, when they are on engine. Only then it appeared, that engine is working on 3 cylinders. Firstly was checked ignition - all works fine. Carburetor also works fine. Needed to check somehow how valves looks from inside. If probe is put from spark plug hole, you will see piston. Then mechanic had an idea to put probe from exhaust pipe all the way to the valve. Since bike has 4 exhaust pipes - one for each cylinder, it worked. Now we had pictures, where it was seen, that valve seats has burned out. Exhaust valves all the time are little opened. That is why cylinder does not keeps compression and does not work properly. What to do - these all are only mechanic parts and bolts  I decided to take out engine, remove both cylinder heads and one, or both (if needed) will give to specialized workshop for repair. My brother manages professional classic car restoration workshop, so he will share contacts for some good partners, what works with such repairs.

In last Thursday I put bike on hand-made stands, so it is easier to work. This week I have much work to do, but I hope that during April I will manage to get engine out of frame. Some experience with technics I have, so all what I need is time   

[Atslega]

First picture was from online market, where I found selling offer for my bike.

The second is in the first day, when I owned it. Previous owner gave together some interesting bag for small things. I took it off. But maybe in some longer roads, where more luggage is taken, it will be useful

[Atslega]

The fist picture is from last summer, when I took off carburetors and replaced fuel lines, spark plugs and other small things. The last two pictures are from last Thursday, when I prepare everything for engine removal work.

I hope I will update this soon

[Marcarl]

Keep us posted, we are interested. If you have any thoughts don't be afraid to ask, better safe than sorry. Have a good time making that baby yours.

[Atslega]

Thanks Marcarl for the kind support

[Atslega]

Since the last post I found two evenings also for motircycle in garage. I hope, that next time I can remove engine

[Atslega]

In my opinion Royal Star is quite simple for repairs. So far everything was easy to unscrew and remove. I have a question - maybe somebody knows, how the propeller shaft can be removed from engine, when I will remove it? Is it just sliding out from gearbox, like for front wheel drive car, or there is some screws or rings to be removed?

[RDawson]

After removing the final drive you can just pull the drive shaft out. It can be tricky to line it up with the u-joint going back in. There is a rubber plug on top of the housing, pull the plug and use a piece of wire to line up the u-joint. 

[Atslega]

Thanks, RDawson, for advice. Will try it

[Atslega]

Today's progress. All went quite ok. Drive shaft just slided off, when I little pushed engine away from it, after all bolts from engine mounts were taken away.

[Atslega]

Engine in his way out

[Atslega]

Hello, 

It`s been some while since last update. So I will write, what has happened since that.

I pulled out engine. Idea was, that valve seats are damaged. After removing both heads and cleaning them, discovered, that seats are almost perfect. Also other parts are not much worn out. What I found - it looked, that old head gaskets were with some silicone covered. It looked like very cheap "repair" done.

I disassembled heads, changed valve gaskets, cleaned everything.

Next problem was, that I put in removed heads camshafts (yes, I know, that in manual is written - do not do that), and it seemed strange to me, that I could not move them. After longer time of thinking, I understood, that design of heads is made that middle part is connected only with some tight aluminium parts (where chain goes). And heads align and are straight, only when bolted to the engine block. Still do not know, if it should be so, but when I bolted them back to the block, I could move camshafts very easy.

I had not time to do this repair every day. I went to the bike few hours in month, so it took quite long to put heads and engine back together correctly. After few more months engine, carbs and all other was back in bike. Started it and.... again one cylinder did not work. Or even two. 

Took again off carbs and checked engine timing. Maybe there was some mistake... Manual for this bike is not the easiest what I have read. And especially timing marks are quite strange and do not match with written info in manual. So, I turned countless times the engine and finally went through all the engine timing with logic. All opening and closing intake / exhaust times looked correctly.

Checked and adjusted valve clearences.

Put back everything again, but now I decided to turn carbs by 180 degrees (so the front two carbs now were rear). It was not so difficult, just needed to make longer fuel hose and few more things. If problem were in engine, then nothing should change. If problem were in carbs, then there should not work other two cylinders. And, yes, I found, that problem were in carbs. But it seemed strange, because they were disassembled, cleaned and changed all rubber parts before one year.

I looked deeper in carbs and found, that at least two diaphragms were very loose (yes, I should check them earlier, but then I hadn't learned the construction of these carburetors yet). I decided, that it was time to disassemble them by myself. I also got many good advices from experienced carb mechanic. I disassembled them and found, that diaphragms were run off the seats, where middle of them is attached. Put them back and this time more accurately. It was most likely, because, when sitting on shelf, old fuel glued needles into seats. And when I started the bike, diaphragms run off the middle parts.

Also there were dirt in few of main jets and other parts. Cleaned everything and put back together.

Washed also fuel tank.

There were also few other smaller problems in the middle (like ventilator, what I damaged and repaired and few other).

In September 2025 bike again was running. I regulated idle with gas analyzer. Maybe engine is not perfect – when cold, on idle one cylinder still do some small coughing time to time, but I think it runs good. When hot, not any problems.

I gave myself a question - why carbs were clogged after one year sitting in shelf. And the answer was - in fuel tank there was some very old fuel left and it clogged everything, when I put carbs back after first cleaning in the very beginning. In Baltics, because of eco additives added by fuel retailers, gasoline is especially bio-active and makes many problems already after 6 months standing in tank. I do not know, how old was the fuel in tank, when I bought it. It was not much there and I added fresh fuel already in first ride to the garage. It was the largest mistake.

Only now I realize how powerful and well-handled this motorcycle is, despite its relatively high weight. There is no problem riding it also with two people. Aftermarket exhausts are a great value. They are not loud, but I really like the sound.

Hopefully I'll be able to go without major repairs for a while and slowly get it back to perfect condition.

[Atslega]