1982 XJ550 Maxim rebuild

Welp, looks like new rings all around now. The hose clamp failed me on a couple more jug reseats, including the new rings on #4.

This is turning into a damn money pit. I may have to part it out if any more major costs pop up. Best I can find is a set on Partzilla for OE STD at around 140.

 

Project is on hold. Will update when money allows.

 

Sorry to hear that. When you say they failed you, I am a little confuse. Did the rings get damaged as they were going into the sleeves? Did you oil down the inside of the sleeves before putting the pistons and rings in? Using a wide adjustable hose clamp seems to work great for most. I have also heard of folks using PVC pipe that is cut to size and split down one side.

 

Yes, they grabbed the lip of the sleeve when going in. The clamp did not compress the ring fully due to the bevel on the sleeve. Part of it poked out as it cleared the clamp and shifted to the side and moved out the land. I have to save up to get a full set of rings and 4 compressors to do it all again. I just ordered a new case gasket due to the new one getting torn during re-disassembly. The head gasket seems OK but I'm questioning the plastic coating on the bore seals and thinking maybe it was causing #3 to leak. I don't really want to spend another $160 on a head gasket either.

 

3 of 4 back together. Looks like I ended up with 3 right and one left bowl somehow. gotta paint that one now. Engine work has to wait until I can get rings and cylinder O-rings.

 

BTW, how do you get the top air jet out of the body? There's no way to push them up (the hole is tiny in the bore) and the inlet hole on the top of the carb is so small you can't even get a pick in it. I have new ones in the carb kits but can't figure out how to replace them. Drill them out and pull with pliers?

 

I'm not sure, but it might be covered here: mikuni carb cleaning.pdf

 

main air jet in throat of carb facing the airbox is non removable.
Pilot air jet under diaphragm unscrews
buy the correct screwdriver or a set of bits or grind down a screwdriver (you would have had to do this for the pilot jet)

why would you want to replace the pilot air jet or main air jet anyways?

 

the pilot mixture screw is under a plug with a hole in it. one has no plug, one has a plug that is about 4mm below flush and the other two are flush. why would the kit come with new ones if I was not supposed the clean/adjust those screws and replace the o-rings? I just did not know if there was a trick to popping out the plugs.

 

for the pilot mixture screw plug (not an air jet) use a small drill bit to put a hole in the plug . be careful it is not that thick then use a drywall screw . screw it into the plug and pull it out.

 

Just reread the thread, did you verity all the jets on the carbs are the same. If someone drilled out one pilot screw and not the others, the jets might now match. I see you cleaned them in supper clean and simple green but I didn't see anything about the jets. Sense you have them apart and broke down, with my eyes now days my readers and a magnifying glass to see them little numbers.

 

This is the plug and mixture jet I am talking about. The screw controls the jet mix on the outer port of the venturi. It is not on any of the diagrams and the only time I see that screw is when the plugs are missing from the body.

 

Yes, I pulled the air jet, main fuel jet and idle fuel jets from 2 sets of carbs for a soak. They are all 120 air and 112.5 fuel. Most of the idle fuel jets were clogged solid. Had to clean them with a 3D printer nozzle drill that would fit.

 

That is the idle mixture screw.
Remove the plugs, clean the passages, replace the -ring, reinstall at the baseline setting, and do not replace the plugs (the brass pucks in your kit), or replace with the rubber plugs that Chacal sells.

 

The screw trick worked great, thanks. The orings were flat plastic at this point so they needed to be replaced a while ago.

Some new shiny screws here and there will finish it off. It is ready for wet set and bench sync at this point.

 

So, since things are on hold I'm working on other projects (customers mostly). Car audio, small engine repair, electronic gadgets, repairing old games and stuff is the norm. I'll try to get some video of some of the stuff I'm working on now like the Humvee swing arm install on the limo for the M249 pintle adapter. Gotta fab up something to attach it to the light bar on the cab roof. Hopefully I'll be back on the Xj550 engine soon.

I dug up the 20mm Time-Sert shear test video I did on the rear sway bar adapters I designed for the Genesis Coupe. If you've ever wondered about strength of a Time-Sert in 6061 billet, here ya go:

 

The turn signal switch was acting up when I was testing the electrical re-install. I guess broken solder joints on the slider would cause problems. Went ahead and refreshed the wire contact joints on all the parts. Have to do the other half next and then toss some paint on the housing.

 

Just for reference, crimp connections are far less problematic than solder on parts that take a lot of vibration. The slider contact rivets might be copper that will accept a tin solder bond but as you can see the bonding is minimal. 18k miles and the solder came off cleanly leaving nothing on the rivet. Avoid soldering anything on a bike unless it is wire-to-wire for stranded wire.

 

very common problem Yamaha did not do very well soldering those wires from the start.. even though it says no clean clean the solder joint

 

I typically don't since it's not an acidic flux residue but due to the age of the board chunks I will.