Harley Exhaust on 80 xj650 Maxim

I've just started installing a pair of mufflers off an 88-04 Sporster onto my Maxim. I'll post some of my thoughts and issues.

I'd be willing to do a sort of check sheet of things to do/not do/ look outs/ etc. but not sure where would be the best place to put this. Possibly one of the moderators could give me some advice.

I'll await some feedback.

 

I'll be doing the same thing in a couple weeks except my muffler was off a larger bike and has the catalysts built into them. I picked them up dirt cheap for my Suzuki GS850 project bike but I have since given up on that bike and now they've been dedicated to the '82 XJ650.

 

I installed some Harley pipes and they went on fine, not having to rejet.

 

how does it sound? louder?

 

Slightly, not much. It changed from the stock, but still does not sound like a Harley

 

I took my shorties off and put a pair of Harley mufflers on mine to see how they sound. They are actually a bit quieter than the shorties and sound like stock mufflers almost. Maybe a bit deeper sound then the stockers and looks nice. I'm probably running a bit rich with them on, but I like the sound they have. I can rev the crap out of it without it sounding so nasty and annoying.
Mine are stock Harley mufflers with the guts intact, so they are more restrictive than the shorties are. But for $20 at a swap meet, I couldn't pass them up and they are brand spankin' new.
Now I have 4 pairs of mufflers for my scoot. The Harleys are the quietest. The shorties have a nice rumble to them and bit louder at highway speeds.
The Jardines are louder and have a nice rap to them. The Screamin" Eagle mufflers are just plain loud and don't really belong on a 4 banger. Too annoying for me. I always have choices!! PD

 

Well I got the mufflers on and it is not a task for the faint of heart.

Overall the sportster mufflers from this era are a good fit in both diameter and length. The mufflers on the 80 xj650 are welded on so you have to cut them off and then use a 1.5" and 1.75 " adapter. The 1.5 end of the adpater is a sloppy fit but muffler cement helped seal it up. If you use mufler cement it sets up fairly quickly so don't use any until you have dry fitted the parts and are satisfied that everything fits OK. Otherwise you'll be cutting it off and starting over.

I cut mine just in front of the space before the muffler and the header assembly but behind the cross over pipe. Contrary to other posts I've read, it is important to leave the cross over pipe in the system. If you take it out it will affect the performance of the bike. If you cut it in this location the 1.5" adapter works OK. Put the new muffler up beside the old one and you'll see the point where you have to cut.

I cut the mounting hardware off the old mufflers and was able to use the one on the left side of the bike ( me sitting on the bike) but had to make one for the right side. They do take some modifying to make them work.

One of the issues on making this change is to recreate the side and center stand rubber stops. These were orginally welded on the left muffler. I solved this problem by just buiding up a weld on the actual stops for the side & center stand. Works great. You might have to grind a little bit to get them right.

If you are doing this switch do the hard side first, which is the left side with the rubber stops etc. Dry fit and put the new muffler beside the old one while it is still on the bike to get an idea of the proper length. The orginal mufflers tend to move out from the frame and you want to duplicate this with the new mufflers, otherwise you may have issues with clearance from rear wheel bolts etc. As the saying goes measure twice and cut once.

I used muffler cement at all the joints on the new install and then tack welding them in place. They sealed off fine and I have no leaks. The cement does make it difficult to weld as it is not a clean surface.

As for sound etc. I had just finished a bunch of painting on the tank etc so I put some gas in the bike today and took it for a ride. I had adjusted the carbs etc last year with the old pipes ( which were in poor shape) so didn't have any real issues as far as carb's are concerned. They are off slightly at idle but work well otherwise. The sound is a deeper tone than the old mufflers but still very much the yamaha 4 cyclinder sound. I liked the sound and it is not overly loud.

If you stay with the sporster series mufflers from 88-04 they work well and solve the problem of were to get a replacement. But this swap does require a fair amount of technical/tinkering ability and the more power tools, including welder you have the better. Or at least have some friends that have the equipment.

If you have any questions I'll try and help.

 

cycleman for recreating the rubber stops I am wondering where you built up the weld. Is it near where they pivot? I just made an exhaust and have not yet been able to figure out a good way to replace the stops. Do you have any pictures?
Thanks
Andrew

 

When I built my center stand stop, I just used a paice of flat stock, bolted to the left muffler bolt. I made it L-Shaped coming down from the muffler bolt so the center stands sits against it, instead of the muffler. I am going to glue a piece of rubber on the bottom so the center stand doesn't "BANG" when I flip it up. PD

 

I don't have any pictures but it is fairly easy to figure out.

To start put the bike on its center stand. Then put the side stand down and look under the bike.

For the side stand fix: You'll see a flat area directly below the pivot point. That's the spot where I welded a small piece of flat metal and then ground it down until I was happy with with the clearance below the muffler. If you have the muffler off on this side you could put some chaulk on the stop and then you'd see where they touch. This doesn't need much of a build up probably around 1/8" or so.

For the centre stand fix: When the bike is on the center stand you see that it comes to rest on two stops. The area you build up is at the other end. You'll see a small weld on the top of the center stand stop and that's where you build the area up with the welder. You have to be careful to not weld the center stand to the frame. Just weld on the one stop as there is no need to try and weld both of them. Do the welding in small stages and slowly build it up. Take the bike off and on the stand until you get the clearance you want.

That's it. I too thought of building a mount so that I could use the orginal rubber stops but as I'm a believer in the KISS principle, ( keep it simple stupid), I elected to go this route. Much simpler.

Took the bike for a ride yesterday, not having the rubber stops on the stands didn't create any weird vibrations. So far so good.

 

Yesterday I got around to checking the carbs as I found that it was running a little rich after I had put on the Harley mufflers.

Set all the idle mixture screws at 2.5 turns as a base line, hooked up the Carbtune. Had to make very minor adjustments to the linkage but this was about it. The initial setting was just about bang on.

I put a new set of NGK Iridium plugs in at the same time as I wanted to try them.

Took the bike for a ride and it ran really well. No hesitation at any stage of accleration. The only adjustment I had to make after it really warmed up was to slow the idle down a bit.

All in all a very worth while project if you need a new set of mufflers.

 

I think I will try this for a seca 750. Does anyone know if the diameter of the 650 = the 750? I see TONS of Harley exhausts but am not sure what the differences are between the sportsters, glides, fatboys, etc...

 

Yes, the 650 Maxim and 750 Seca outlet on the collector box outlet is the same on both. I think it's 1-3/4" if I'm not mistaken. Sportster mufflers will fit right onto the headers. They sound just a little bit louder than stock mufflers (maybe a bit deeper tone) but aren't loud by any means.

 

Thanks Painter!

 

OK I bought some Sportster exhaust off of EBay, let's see if we can make the Seca sound a little healthier! I have GSXR exhaust on there now.

 

Update. After a few short rides and keeping track of the plug colour, I've noticed that the plugs are too light in colour. I don't know if this is because of the type of plugs or fuel mixture. So I've opened up the pilot screws to 3 turns, used the Carbtune and will try that setting. Vacum readings didn't change. I don't worry about actual readings just that they are all the same or as close as possible.

First impressions are that the motor pulls better with this setting. Only been up to 7000/8000 rpm but no hesitation/miss. Definitely quicker off the mark. This seems to be the best setting for this bike.

If anything changes I'll post again.

 

Were you stock with the Pilots before?

 

I had used the Carbtune on the bike last year and I would have been in the 2.5 to 2.75 range, ( which is pretty stock on these bikes) but I was using the standard NGK 7BPES plug for this bike at that time. The Iridums I installed this year have a much smaller electrode tip so they are different. I also use 91 octane fuel.

I have since pulled the plugs and tweaked #1 open a bit ( still too light), #2 (closed a bit) and #4 (closed a bit -too rich). A tweak in this case is just a couple of degrees of turn. I didn't hook up the Carbtune for this as the adjustments are so slight that it would drive you nuts.

Went for a short ride on the weekend and bike seems to work fine. I know I'm in the right area so I'll check again in a few days and see if they need any further adjusting.

 

Well my Harley exhausts are here. Let the surgery on the seca begin!

 

iv cit the maxim X700 i want to change the exhaust to something with a nice note anyone got any pics please on or off your bikes
CHEERS MUCHLY