What Is Missing Or Is It Worth The Build?

It’s funny how things go... I’ll bet if you do some searching you’ll find more 750 seca’s for sale and find a crashed one or a left for dead one for cheap and have all the missing parts you need.

 

Yeah there are always options and thats one thing I have really been hoping to find lately. Even being able to find someone on here who has extra or spare parts would be awesome. But it reeky could go either way. Personally, I would love to try and build this the way I have it imagined. I just don't want to end up in a bind with it and then it turn into a money pit to become something that will never be completed. So I guess it will just come down to whether or not I want to put in the effort and money. Like @hogfiddles said, I could just not worry about the $ and enjoy the build.

 

Yup... if you go about it the right way, you'll become one of us. I started with one bike to fix up... got 2nd place trophy after several years. Now I have 8 more trophies for a different bike.... and a whole herd of bikes. So does ' Toomanybikes '. Just buy all the ones anywhere near you and you'll eventually have one running, and a gazillion parts. Heck, you might even become the Southern Parts Hoarder!

Dave F
Northeast Parts Hoarder

 

Starting to sound more and more like a plan! I really have wanted to get more into motorcycles lately and it has become a strong interest of mine now. So I guess the path I will take now is to see what I can do with this one and work from there. Finding the parts will be the first step, but my main priority will be to have it running. All the while taking it slow and doing it correctly. One day I may end up with a nice collection of old, restored motorcycles, who knows...

 

Or, you may end up like some of us.......a few running bikes, a couple really nice ones, and a collection of many more

 

I can write from experience that the big issue for a newby is that there are so many variants of xj (fj even), and breakers sell stuff as xj with no referance to seca/maxim/engine size, and ver often just quoting one of these for effect. So you buy the wrong stuff, but you learn fast!
Good luck, don't rush, get there eventually.

 

and that's why guys like us are here

 

all relays can be bypassed the soleinoid is the only one you need.

 

"Just buy all the ones anywhere near you".
And by that Dave means somewhere on this planet. Although I bet he is in negotiating with Sir Richard Branson for off planet shipping. Just in case you know.
John

 

I found this website called MRC Cycle and they have tons of XJ parts but parts for other bikes as well. I have even found the majority of what I believe I need to get mine going. I would recommend checking it out if anyone hasn't already.

https://www.mrccycle.com

 

Watch the prices and be careful. Some of what they sell is priced good, but they are asking $16.50 for a used air filter, plus almost that much for shipping. A new one costs under $17 with shipping charges included.

 

Yeah for many of the parts I have searched for I have been comparing the new to used prices before I get deep into something that turns out to be worthless.

 

So you need some carbs off a 650, a cdi and a battery, I think you can ignore the rectifier/regulator? Someone please confirm? If you have 12v at the coils and a cranking engine it should run. Make up a fuel can on a flexibleto feed the carbs.

 

I've never had any issue with them

 

Just tried the bypass system and the motor turned over. For me, thats a great sign since I wasn't too sure of the condition of it so now I know it isn't locked up. But I still have to by the ignition coils for it to fire up.

 

The regulator and rectifier have to be in the system, or he'll get raw A/C into the TCI. That will turn out badly.

 

Surely without rectifier there is no connection to the dc side = battery voltage only?

 

The alternator feeds the R/R. The alternator is three-phase AC.
As long as he's only hooking up to the battery, and keeps the alternator out of the loop (entirely disconnected from the harness), then he'll be fine; total-loss DC.

 

I think that's what I said kmoe?

 

On the home page go to the For Sale/Trade , you may find someone on the forum selling items you need. One thing you should try now that bike turns over , put a little oil down plug hole , and put a compression gauge on see what the cylinder reads . As long as it is more than 100 psi your probably ok , the valves need checked and adjusted (Clearance adjusted =shim change) I know you want to see if it will run , but this is all items that at some point will need checked . Tight valve clearance can effect compression and is usually the exhaust side .

 

Great! Thanks @Jetfixer for the advice. I definitely have been searching all over the sale/trade page and I eventually found a post that I was looking for. So now we working out an agreement now to get the parts that I need. Also, is there a section on the home page or under the How-To’s that will show me how to either rebuild the engine or replace the valves if needed?

 

I wouldn't even think that far ahead until you've checked the compression, if you're able.

The manuals give a blow-by-blow, and this link would get you started, if you find you need a full rebuild:
https://www.xjbikes.com/forums/threads/xj750-engine-removal-and-split-pictures.38545/

 

Well the thing is I don’t have the ignition coils or most of the wiring harness, such as the CDI, to be able to check the compression just yet.

 

Great! Thanks for the link. I believe it will be helpful in the very near future.

 

Now think about that - why would you need a cdi or coils to check the compression ratio?
Crank the thing over - you need a battery, see if you have compression. If you do, see if you can measure it. And in the meantime order some coils and find a tci, then you might be able to run it

 

Still kind of new at this lol learning from it as I go really.

 

Honda CB750 Coils will slot into stock mounting point and still can be bought new , these have replaceable plug wires as well . Cycle Recyle Part 2 carries these 44$ each and they also sell plug wires and spark plug caps as well. Be cautious buying used coils if the housing is cracked , they can be filled with epoxy , but you won't know if they are good or not ..

 

Yeahh it’s always a gamble with used parts and that’s what I’m trying to steer clear of unless I know for sure it was coming off of a running bike.

 

Yeahh it’s always a gamble with used parts and that’s what I’m trying to steer clear of unless I know for sure it was coming off of a running bike.

 

On a side note... if/when you're able to crank the engine and check compression like @Minimutly described, just remember your compression numbers might be a little bit low. That's normal, because you're testing a cold engine.

 

Just make sure you clean the plug recesses in the head of any detritus before removing the plugs, then drop 5 ccs or so of oil in there before you crank it over.

 

Okay, I'll try that as soon as I can get a chance to. Thank you for the help. So the compression should read above 100, right?

 

Higher. If it's below 115 on a cold engine, I'd be pretty concerned. I think you want over 120 and under 170. Closer you are to the middle of those two numbers, the bettter.

Going off memory, though.

 

Okay, I'll check it out and then I will let you all know. If it's below 115 that would possibly mean it needs a rebuild? Or what else could it be?

 

Hold on as engine has not ran for awhile as I mentioned valve clearance could be off and an engine that is running tends to have better compression. First take all the plugs out , ensure you have a fully charged battery this is important a slow turning engine can give lower readings .

 

Alright, thank you for the help.

 

Okay, I did my compression test yesterday and here are the results. I took the advice of putting a little oil down the plug head as well. Keep in mind too that these numbers are for an engine that has not ran in a while.

cylinder 1: 125
cylinder 2: 150
cylinder 3: 90
cylinder 4:118

The 90 is what concerns me, but it could possibly just be due to it just sitting for so long. Any thoughts?

 

Even at 90 psi it should run , really should check valve clearance on that cylinder , I doubt rings are fully behind lower reading , if valves don't seat fully .

 

So how would I check the valve clearance? Would I need to take the top covering on the Cams off? Or what would you suggest @Jetfixer? Do you know of any how-to videos on how to check the valve clearance.

 

Grab a good feeler gauge, a pen and paper. On youtube, just type "How to adjust motorcycle valves -- Shim style" There's a video by MrMaxStorey that pretty much covers it.

There are probably a few others out there.

Not the same model, but the general steps are the same on all these bikes, I think. I would suggest something better than a zip-tie because they can break too easy. There are quite a few forum posts on here about it.

Easy enough

 

Yes the cam cover has to be removed , held down with several Allen bolts , take a piece of cardboard draw an outline mark where bolts go to keep in proper location. Pull all 4 spark plugs, remove the crank cover on right side of engine , a large zip tie bend end 90 degrees . Look in spark plug hole , you will see the valve tip , use a wrench turn the engine clockwise till the cam is lobe is opposite face of shim . Take your feeler gauge measure clearance , write down all readings , front is exhaust rear is intake . If using chart in manual if any are out of clearance, this where zip tie is used move can lobe to where valve is fully open. Insert zip tie thru the spark plug hole to where top of tie is under valve tip rotate engine over with wrench till cam lobe is 180 out from shim if zip tie is positioned right should be snug , you can now remove shim , a pick or small screw driver gently pry shim out. On the bottom of the shim is thickness write down number and use chart to figure what needs replaced. If you have a 280 you might need a 275 , caution do not turn engine over without a shim in place . It is best to pull shims one at a time write down readings and you might get lucky by moving shims around. When I did mine I needed 3 shims local dealer had them 9.00$ each . I usually start at the intake and then exhaust on one cylinder . This sounds complicated but is actually easy , after you do this it might scare you clappy valves are happy valves. There are some more detailed posts on the forum , sure I left something out but hope this helps . Go to the the how to section big fitz has a post with pictures on how to adjust valves.

 

Alright. It’s a lot, but I think I can get it done. Thanks for the advice and I’ll check it as soon as I get the next chance to do so. I’ll post my findings on here as well.

 

[QUOTE="hogfiddles, post: 604096, member: 1387"I'm building a couple MaximX's from scratch and parts......one is where every part is either new, refinished, or detailed. Here's when one started when it arrived in the mail last week.
View attachment 31371

It's only missing a few more parts than yours....

Dave[/QUOTE]
You should do a build thread.

Gary H.

 

You should do a build thread.

Gary H.[/QUOTE]
I've thought about it, but before I can start a build thread I think there are a few more things I still need to learn and know about. I'm still a little new at getting into motorcycles and its individual parts. But once I become more familiar, I definitely will be making a thread for it!

 

@Aisaakh99: Apologies. I wasn't trying to Jack your thread. I was actually talking to Dave regarding the X with the Virago front end. Your on track with the 750 tho. I believe the help you'll need to make your bike a solid runner is here. As jet said...the compression #'s are ok for now. These bikes were well built. The parts bike will immensely cut cost. As long as the structural integrity of a component or assembly is intact and or within spec and re-build parts/kits are available it can be re-built and will function as intended. Welcome aboard, your labor of love
journey has begun. Hope this helps.

Gary H.

P.S. - This is your build thread.

 

Don't need to do a build thread.... The parts are all the same except:
1. the lower triple clamp has a small hole on either side for the emblem
2. the headlight mount is different because the emblem is different ( the original Xj 700 headlight mount and emblem can still be used instead)

The WHOLE reason for doing this really simple---I like the virago fork emblem better. The ironic thing is-- the virago emblem will fit right over the xj700 emblem. The only issue there is you'd have to either drill the holes, fill the sides with RTV to glue the emblem on.

I can do a thread, though, if you prefer.

 

Oh its no problem. I have had a ton of help from the people on here and am so far on the right track because of all of that help. Next thing you know, she'll be running like a champ on the highway.

 

Thanks tho.

Gary H.

 

Gary, it's a super-simple swap-fit, I'll take pics for ya.....but you'll see what I mean when ai show you. I'll work on that in the next days or two

Dave

 

So here is how my project is coming so far. Thanks to @joe elliff for being a big help with getting me a whole new harness, CDI, regulator, carb rack, and etc. one I stripped off the old harness I proceeded to put the new one in. Even put the ignition coils on as well. As far as the headlight, I am still working on wiring it all up correctly. I did an electrical test, and everything has worked so far (minus the headlight because of the wiring). Once I have all of the wiring set up, I’m on to the carbs next. Are there suggestions or things I need to change around before I continue?