Delkevic xj650 seca exhaust on Maxim?

I searched haven’t found much information on this but I was wanting to try this exhaust on my Maxim 650. I know for the most part it will mount up but curious about the stops for the center and side stands.
Anyone have experience with this?
TIA!

 

What do Delkevic say about fitment? The Seca and Maxim engines are the same l believe.

 

Basically, yes, but the frames on the Maxim and Seca are significantly different. Now, I haven't tried fitting an aftermarket system (be it Delkevic or others) on both models, but the stock pipes certainly won't interchange.

 

Yes I did see one on YouTube with the delkevic exhaust he only really recorded the sound while riding no close up pictures. I truly hoped he was in this forum.

I found a new old stock Mac system for sale but they want the mint for it.

 

You could try Marving. They make new stuff. Not cheap, but you have to keep your expectations realistic.

 

Oh I know that it’s not going to do much for the power of the bike or be perfect by any means. My factory system has some pretty good rust on it in the crossover and the pipes joining the muffler on each side.

 

I will say while the Marving exhaust looks very nice I don’t think I can spend 670 dollars for it. I paid 1000 for the bike and then another 450 to get it running properly. It’s all complete and never been hacked on it’s pretty nice and original. Just aged some. Has 25000 miles on it. So it should go on for quite a bit more miles as is. The intent to buying it was originally going to be to build something custom with it but it’s a shame to cut up on a complete and nice bike. I see it being more valuable left alone. Just didn’t like the rusty exhaust and the right muffler has some dents on it.

 

Harley sportster mufflers might fit. Some XJ owners have them. Clean the headers up might work. Can you post some pictures of the exhaust system?

 

It’s not much to look at. It’s been touched up by the previous owner with silver paint on the header tubes, and there is rust on most of it. I am pretty sure a replacement is in order if I want to make it nice again.

I did get a response from Delkevic about their system. They said the pipes won’t be an issue and will fit to the bike but the muffler bracket won’t line up. I would need to make a small piece so it would attach. That’s an easy fix.

 

That's right the seca one just needs the rear bracket made up to suit the maxim frame.

 

I may pull the trigger on that delkevic exhaust if I do so I will post up how it goes and any shortcomings it may have. I suspect I may loose a slight bit of ground clearance but it shouldn’t be of too much concern since the loss is going to be near the frame and not hanging out the side of the bike. So if I go log jumping I might get stuck lol.

 

Do you need to change jets? I have a Motad system on my 900f.

 

They say no and I have installed a similar system from them on a cb550 had no issues with stock jetting but I did decide to go up on the main jets anyway cause they also wanted pod filters on the bike. It runs like a scalded dog. But those are regular slide carbs not cv carbs.

I already have gone up on the jets I have 122 mains and 38 pilot jets in my bike. It runs good but a bit rich. That’s with stock airbox and exhaust. I have the ability to go to pods and exhaust and it would likely be spot on. Right now I am awaiting the correct spark plugs and new plug caps as someone has swapped the plugs for resistor type and the original spark plug caps will shock you if your grounded and touch them.

I am probably going to do it all but first I want to install fresh “correct” spark plugs and see how it runs. Then if that works out I will go to pod filters. Then check the mixture to make sure it’s good and see how she runs and responds. I am pretty sure it will be good with the pods but I like to take it a step at a time.

 

Lol, you hope. Experience says different.

 

What’s your experience? Have you done the pods on your bike? What’s your setup or opinion? I mean don’t hold out.

I am just going by the way my bike runs. Checking the plugs etc. I spent a lot of time on the carbs and getting the fuel levels correct and so on.

 

Correction on the pilot jet size. 40 is what is currently in there. It’s possibly too small but I am going to see where I am once the filters go on. Little changes big differences.

 

Well, I run xj600 Mikunis on my 650 non yics. I tried them without filters, they worked "great". I ran them with cheap Chinese pods, ran the same, but the pods were poor, and I was too mean to buy a set of K&Ns. So I fitted an xj600 air box. Now this is a complicated thing, with built in helmholtz resonator, and somehow it demands that the No2 carb needle is very different to the others. I also found that the needle circuit was slow coming on - like 8000 rpm. So I've done some comparisons between Mikunis and the Hitachis - one of the big differences is the slide springs, the Hitachi ones are way weaker, and I believe this makes them more sensitive to upstream pressure, the upshot being they lift sooner, lowering the vacuum at the main jet - instant weak mix..
All theory and conjecture I have to add, but based on the theory of operation of these things.

 

I'dsuggest that #122 mains are way too large for the 650 engine (stock size is #110) and #38's are too small (especially if you start adding more airflow capability)....stock size is #40.

Normally, when adding pods AND a 4-into-1 exhaust you'd go up to #114 or maybe even #116 on the mains, and up to #42 on the pilots.

I'd wager that the #122's are causing the rich condition (fouled plugs).

 

I actually have the 40’s in there now. I forgot that the kit I received was for the 650 or 750 it came with sets for either model.
I will agree it seems that the idle jets could stand to be a 42 or so. I may depending on my mood drill them out as I have two sets of everything. Worst case I go too large and have to fill them and redrill them. Done it before with great success.
It was a pain to get fuel levels corrected and that has shown itself in too rich a mix on the enrichment circuit. It still works but you have to judiciously use the choke or it will end up too rich.
I want to get it right straight away and will probably be throwing the 4into1 exhaust in as well. So I will start at the idle jets get those correct first then take it a step at a time to get it just right. It’s going to require multiple times of me pulling the carbs. No doubt.

 

Delkevic advised we offer a system for the 1980 750 maxim, but I cannot see anywhere on our system that confirms fitment for the 650 maxim unfortunately.

 

The 650 system should fit the 750 as well.

I just got my new spark plugs and went back thru synchronizing the engine once more it’s running nicely. It’s on the razors edge of being rich on the mains and a tad lean on the pilots I will be changing out the pilot jets as I feel that the mix screws are too far out. They are about 3.25 turns out per carb they differ slightly from one to the other as well in a perfect world nothing is perfect. I will be going up on the pilot jets just to bring in a finer adjustment. Ideally would like them to be between 2-3 turns out no more than 3 for sure.

It’s snappy though runs smooth and holds a nice steady idle at about 1050-1100rpm on my digital tach. Which surprisingly matches the factory tachometer pretty close. I am just a sucker for getting it exact.

Shout out to @chacal for getting me the plug caps and spark plugs quickly! A noticeable difference in the way it runs now.

 

Still at work on this I got some filters today but they were not going to work correctly. They covered the air bleed ports and would have wreaked all sorts of havoc. So I found a different set it appears these have no lip inside them to cause blockage of any ports. They arrive tomorrow.
I will probably have to go richer on the pilots but I am going to leave the mains alone till I can get a good run down the road on them.
I need to figure out the way the enricher pulls fuel and air and make some adjustments there. It’s odd cause it worked fine with the fuel level below the spec but now with the fuel level up properly it seems too rich but as far as I can tell there isn’t much I can do about it. All that was done with airbox in place.
Any thoughts or have I missed something about the enrichment circuit?

 

Well as previously mentioned the main jets are too large. The idle jets seem good. It pulls away nicely but starting around half throttle it’s really flat. It still pulls and has no issue going well more than the posted speed limits but the overall acceleration has suffered some. Not huge but still some.

 

Well correction I pulled the spark plugs it’s still too lean! After a 40 mile ride they are all between white and just the slightest hint of tan on the ceramic around the electrode so either the jets I got with the kit are junk or they just need to be bigger.

 

Well I figured out what they did. They have a set of 750 carbs on the bike. So.. even with 120 mains it’s too lean cause the main air jet is larger. So I need the air jets to correct it.

 

Air jets, ever wondered why they are there?
On the face of it, you have air flowing through the carb, sucking fuel from the main jet, sucked by the vacuum created under the slide. So why need an air jet, the jet under the needle has an emulsion tube, which has holes in its side, which should let air in to "emulsify" this fuel?
Well the thing is you need to meter this air as well - too much and the fuel level in the tube will drop, too little and it rises to provide neat fuel at the jet...
So, the poor little, rarely given attention air jet has an important job to do, in the balance of things, as has the emulsion tube itself (holes, number of, top orifice diameter), as well as the needle and spring.
So when I hear people saying "this mod needs x and y mains, x and y idles" I do have a giggle to myself and wonder if that might actually be somewhere near right?

 

I understand how they work just ponder the consequences of leaving the 750 air jets and replacing the pilot and main fuel jet to compensate for the difference. I know they have a direct impact on the fuel delivery curve that’s the part that makes me most curious. So I would imagine the air jets make up a larger difference than any of the fuel jets and quite possibly even the needle taper profile. I have far too much time and effort into them to swap them with anything else.