XJ700 Engine swap

Due to excessive oil consumption and increasing running problems, I decided to swap the 53.000 miles engine to a (reportedly) 5000 miles one.

The "patient":



Exhaust, gonna see if I can give it a proper clean (was disassembled in 2007, so shouldn´t be to hard to get apart):



carbs off, ready for the Jack:



"new" engine installed:



header pipes soaking in phosphoric acid, will check valves and alternator brushes before start-up.


Only 2 caveats so far: Wiring from old stator was made with three seperate connections as opposed to the original 3-pole plug + a puzzling extra earth connection was made from frame to battery case bracket; according to Tony/"xHondaHack" and others not original, so I´ll leave it out.

 

Checked alternator brushes, like new

(on a side note: tried a modified Bosch brush once, not a good idea! Looked like this after around 6000 miles:



Top of, ready for valve check, looking like new in here with a good, tight camchain :



Gonna paint up the rusty spots on the frame and paint the Dynacoils black.



No valves were tight, 4 shims needed changing, all original Yamaha shims in there.

 

Not its first valve-check, one of the ignition cover bolts in pretty bad shape:



On the 900 the bolts are plain, changeable with normal allenheads (Len, you make replacements like you do with the carb drain screws ?



Valve cover gasket fine but on 4 of the bolts somebody installed a washer. Didn´t pay attention to where they were located, so gonna clean up the old ones and see how it goes, and if leaking, get new "donuts".

 

Spend a dollar and get 4 more washers ,
That DYNA coil looks older than the bike !! I'd paint em too

 

Right..

Yeah, that coil is always facing the sunny side when parked

 

So, a little update - days are getting shorter and colder rapidly, near zero degrees C last night, luckily no salt on the roads (yet).

1.st step electrical, turning the generator connections back to original (old system had an over charging issue, making regular battery-checks necessary - and, obviously, a bad connection from one of the phases)):



Trying to prolong Clutch cable-life with 2 x heatshrink:




Frame spot-painted, Dynacoils sprayed and aftermarket horns mounted to the lower holes of the coils´ core (the original horn-bracket has always annoyed me when removing valve-cover..). Sound of the new horns pathetic but so were the originals..

 

Carbs were a lot harder to mount on the "new" intake rubbers - the wood prevents back-sliding, a lot of pull force on the other side ´till that side popped in - and then alternating wood/pull-side:





Exhaust disassembled, pipes (partly) de-rusted in phosporic acid and polished, mounted with new gaskets and anti-seize paste. Assembled pipes and collector first ´cause I was afraid I wouldnt be able to push the pipes in if I mounted the parts on the bike seperately. Had to pull the pipes out a little bit to get the collector to line up with it´s mounting hole but thanks to the paste, I think, I could wiggle and push each pipe back in to place.

Gettin´ somewhere





After the exhaust: A beer and small parts (footpegs, brake+shifter lever, tank etc.)

A deep breath, a final thinking, petcock on "pri" for a moment, choke on and she started right up

Test ride postponed because the sidestand switch had seized, a little WD-40 brought it back to function and of I went. 1st stop after a few miles to adjust the idle revealed valve cover leaking from the right side (to be expected from the washers on some of the bolts I chose not to use). Will attend to it when I hopefully get to make a carb-sync and oilchange before riding season ends.

In the sunset during 1st test-ride enjoying a (well-deserved, I think coffee and the years last outdoor-icecream break



Summing up: The "new" engine seems fresher, more torque, despite staying below 6000 rpm ´cause of low ambient temp and relatively short ride. Gear-shifting is worlds apart from the old one; same "clunk" into 1st, the others much more precise/easy/refined. Hoping for a few more sunny days before winter

 

Cool, I just finished an engine swap on an XJ700, need to tweak the carbs but I heard it run this afternoon.

 

It´s one of those defining moments, right ?

 

What size/model is the donor engine from?

 

Looks like he put another 700 engine in. I THINK the reason the 900 pic was there was just as a reference for the four cap screws he asked about.......

dave

 

Right, Dave. The bike is an ´85 XJ700N Maxim and the donor engine is from an ´86 XJ700S Maxim - and yes, the XJ900 ignition cover is held with 4 regular bolts, easyli replacable with Allen-head bolts.

For the 700 however the ignition-cover bolts looks like this so alternatives has to be made (that´s why I thought of you, Len
(The rubber "donut", similar to that on the valve-cover bolts, might pose a bigger problem though - haven´t tried if it´s removable without breaking it)

 

I would like to know if such a replacement bolt was available, as well. For the 700 (non-x).

 

Yes, we do have this special bolt available for both the 1985 and 1986 models (1985 are bright finish, 1986 versions are black), and they do come with the rubber sleeve:

HCP1005 OEM oil pump covers MOUNTING SCREW, pan-headed phillips drive, bright finish. Uses 4 per cover, 8 per bike. Fits all 1985 XJ700 non-X, all XJ700-X, and all XJ750-X models. NOTE: N and NC models used 4 of these screws per cover, 8 total on the bike. XN and XNC models used only 7 of these per bike: 4 on the left side cover, and only 3 on the right side cover. Comes with the rubber washer. The one additional bolt for the right side cover, which is very unique and specialized, we do not have available anymore.

HCP1004 OEM oil pump covers MOUNTING SCREW, pan-headed phillips drive, special design, black finish. Uses 4 per cover, 8 per bike. Fits all 1986 XJ700 models. NOTE: S and SC models used 4 of these screws per cover, 8 total on the bike. XS and XSC models used only 7 of these per bike: 4 on the left side cover, and only 3 on the right side cover. Comes with the rubber washer. The one additional bolt for the right side cover, which is very unique and specialized, we do not have available anymore.