New member with an old XJ

Hello all. I'm new to the site and want to introduce myself. I have an 81 Maxim 550 that I bought 15 years ago when I was 17 from a friend. The carbs were in pieces from him botching the carb cleaning. I put it back together and luckily it started & I rode it for about 3 years until it went south on me. After it started running a little rough, one day a mixture of oil and gas came flooding out the airbox. So I took the carbs off and dunked (all 4 still assembled, haha) into some cleaner. Needless to say I didn't get it going again, I was making good money so I bought a new bike and stored the Maxim for "one day".

After college, a friend of mine was interested in the Maxim. I told him if he could get it running it was his for cheap. I think he stripped the carbs down but I don't know what all he tried. He couldn't get it going so I stored it away again back in Illinois.

Well, it is "one day" now and the Maxim has sat all of this time. I sold my Intruder (awesome bike!) a few years ago cause I didn't ride it much and needed some Jeep parts and a new tv. I've got the bike bug again! I'm gonna get this Maxim goin'. I always loved the way this bike ran but have never cared for the style. So, I'm gonna make it my own with a little cafe styling (ditch the big ass seat, the tear shaped gas tank), but that will be part of Phase 2.

While researching getting the bike going, I came across xjbikes. What a great site you all have created! Tons of great information for such a small segment of motorcycles. I never thought there would be this much information on these Yamahas. I've been lurking on here for a few weeks, gathering information and I feel I have a great plan of attack to get this Maxim going (once I get it from back in Illinois to out here in mid Missouri). Here's my list to get it going:

Phase 1- Get the Bike Running
I want to make sure it will run before putting much time and money into it.
1. Purchase a battery
2. Mystery oil the cylinders and change the oil.
3. Clean & gap the plugs
4. Pull the carbs and do a full disassembly
A. Fully clean all parts
B. Polish the bores
C. Reassemble, greasing all gaskets
D. Bench sync the carbs
E. Make sure it passes the "clunk" test
F. Return the carbs to factory settings
5. While carbs are off, do compression test

Hopefully, after this I can get it to fire and at least idle roughly. I'm not looking to run it at this point but have better peace of mind about my plans for it. More about Phase 2 later...

Look forward to getting to know this YICS motor better.

 

How's that mid-Mo summer treating ya? I don't miss it! Originally from Columbia.

1. Good, you're gonna need it.
2. Changing the oil is good...but should have been done periodically while it was stored...especially if it wasn't instilled with fresh oil before being stored. But worse things have been done.
3. Get new plugs...it's worth the $12. Get new plug caps too. Also well worth the cost.
4. If you plan to completely disassemble the carbs, make sure you have new throttle shaft seals along with all the other gaskets. Unless you want to do it twice, of course. If you had gas in your oil you have 2 problems concurrently. The petcock is leaking gasoline, so you will have to rebuild the petcock, and the float valve needles are leaking (or sticking open), and you will need to replace those and reset the float heights.
5. You'll want to compression test the engine with the carbs on the bike, throttle completely open. The airbox to intake flow will have an effect on the compression that you will want to know about.

6. Check your brake shoes for delamination. In general, while ensuring it can GO...make sure it can STOP.
7. You probably need to check the valve clearances too.
8. Try turning your mixture screws 3 rather than 2.5 turns out to start with. Fuel has changed since 1981. Especially Missouri fuel.

 

The first thing you want to do after getting a good battery is to CHECK THE VALVES! This should be number one. Then start messing with the carb etc. If your valves are off, it isn't going to do you any good cleaning, adjusting the floats and doing a sync on the carbs. You also want to do a colortune after you get those carbs cleaned. BigFitz is the guy to ask if you need help with any of these things.

 

WELCOME from TN and GOOD LUCK!!!

skillet

 

Do you really what to strip the engine and rebuild it? Will be a heavy job and I can not really see it needing it as XJ engines are pritty much bullet proof unless badly neglected for a long piriod of time.

 

I'm pretty sure he meant "pull the carbs and do a full dissassembly on the carbs

 

Thanks all. I will definitely be checking the valve clearances. Depending on what happens after I clean the carbs will determine when I check the clearances. I know that I will for sure be in the carbs at least twice, so setting the floats & sync twice is a guarantee. I will be installing pods and probably a 4 into 1 exhaust, so rejeting will be in the future at the end of Phase 2.
At the end of Phase 1 I will not be riding the bike. Phase 1 will only be about firing the bike up but not tuning it at all (or at least as little as possible)
Heres a quick overview of Phase 2.

1. Purchase carb kits, valve clearance tool, YICS tool, head gasket, pods, fuse panel, clutch arm spring
2. Check valve clearances & purchase new spacers where needed
3. Pull the head & re-seat the valves
4. I know the outer clutch arm return spring broke off of the side case. I'll replace that.
5. Go through the carbs again again with the carb kits. Bench sync. Vacuum sync.
6. Check brakes (rebuild what is necessary)
7. Clean electronic connections
8. New tires

Preliminary Phase 3

1. Remove factory air box & battery tray, fuse panel
2. Check salvage yards for a different gas tank
3. Retrofit new tank
4. Cut off rear frame and decide on a design for the tail (which will house the battery and electronics
5. Simply the wiring loom
6. Drop the front forks a bit
7. Install clubmans or clip-ons (depending on tank)

 

That is correct Day. Just going to disassemble the carbs for a thorough cleaning. Though I may pull the head and reseat the valves. If I remember correctly, the bike has around 27,000 miles on it so a valve job may need to be done.

Since this was my first street bike, I wasn't very easy on it. Luckily I've learned alot about engines since my younger days. I have a much better idea to get it going again.

Thanks all.