Trying to remove Nighthawk 700 engine

[SmokinFast]

Hi. My alternator chain broke, so I'm trying to remove my Nighthawk 700 engine. I followed the Shop Manual procedure until the last part where it talks about the swingarm. It says to pry it back, but its very vague and doesnt say anything about the 4 allen bolts on the swingarm case. I think they left something out of the instructions. How do you get the engine separated from the swingarm?

Here's a photo showing where I'm at. The only thing left to remove are the frame bolts holding the engine on and the swingarm, but I'm not sure how to do the latter?

[gammer]

Don't touch those 4 allen bolts.
You actually need to pull that rubber boot back where the swing arm meets the engine. Get a long flat head screw driver and pry back the cv joint under that rubber boot. The cv joint is spring loaded. Once you have it back, stick a screw driver in the hole in the middle of the swing arm bolt that you can see in this pic. The screw driver in the bolt will hold the cv joint back in its place, out of the way.

[Brittles]

Good information that I need to know.

[Munkey]

Unfortunately, I may need this information soon also.

[SmokinFast]

Thanks Gammer, that helped. The final drive gear just slid right off of the shaft after I rotated the engine out through the right side of the frame. I have the engine resting upside down on styrofoam now and will split the cases tomorrow. (photo below)

Questions:
1) To replace the alternator chain, do I need to remove the transmission or just the crankshaft?
2) How hard is it to get the alternator chain onto the gear on the alternator shaft?

Thanks,
Brett

[gammer]

1) To replace the alternator chain, do I need to remove the transmission or just the crankshaft?

You do not need to remove the gearshift drum or the casing where the oil filler hole is; leave it attached to the bottom case. You will have to remove the cross shaft casing.

Tips: There are a pile of 10mm bolts around the outside of the bottom case that need to come off (as well as the larger 12mm bolts in the middle of the case). But there is also about three 10mm on the top of the case that need to come off. So flip the engine upright and look on the clutch side, and you should see a couple there, and there is 1 hidden 10mm bolt on the gear shift side that is in a recessed area.

Another Tip: The rubber mallet is your friend. I used a rubber mallet to free the cross shaft casing and I *really* used the rubber mallet to get the cases separated.

Once the bottom case is off, you will have to pull out the transmission (gears). It comes out easy, but just take your time and be careful. You don't want to have any of the gears slide off. I remember there was some washers on the ends of the shafts that can fall off easily.

2) How hard is it to get the alternator chain onto the gear on the alternator shaft?

Once the transmission is out of the way, you will see quite clearly what you need to do to get at the chain.
On the crankshaft side, you will need to un-bolt the rods from the crank shaft. This will allow you to lift the crankshaft up a little so you can slide your new alt chain into the gearing on the crankshaft.
On the Alt shaft end, you will need to remove the bolt on the inside end of the alt shaft.
Do you have the manual? It outlines this process in there.
I remember that my release rod for the alt chain was broken clean off, so I used a flat had screwdriver to press the chain tensioner down and I slid the chain on with the tensioner out of the way.

p.s. Be sure to get all the broken pieces out of the crankcase...like the broken chain bits (if any) and the release rod.
Be sure to grease anything and everything before re-assembly...all the bearings, crankshaft...etc. Be as liberal as possible.

What are you going to use as 'goop' when putting the cases back together?
I used a product called Hondabond 4. Its made specifically for cases that don't have gaskets.

[SmokinFast]

Those tips will be a tremendous help -- thanks again gammer.

I have the Shop Manual. It got me through most of the engine removal, but it is not nearly as good as hearing tips from someone who's actually done it.

I was going to start splitting the cases today, but I'm leaving for a short vacation on Monday. I don't want to be part through it and stop, so I'll start this on Friday.

I'll take photos in case anyone else has to do this.

[gammer]

I'll take photos in case anyone else has to do this.

Good idea...trust me, there will be others who will need to do this. That alt chain breaking is a common failure on these engines with higher millage.

On another note...I am kind of paralleling you. I am rebuilding one of my spare 750s engines that has very low millage on it. I suspect it needs new shift forks as the PO got it "stuck in gear" after abusing the transmission from lack of knowledge of shifting properly.
Anyway, I am just about to split the case on my rebuild too. Probably going to get it split in a day or so...as time permits. I'm toying with the idea of getting rid of the alt chain tensioner release rod, so I don't have to worry about it breaking off in the future.

It sure is nice to work on something without pressure of having to get it back together for the sake of having something to ride. While my current engine might have high millage and is tired. At least it runs fine and I can enjoy two of my favorite things: riding motorcycles and tinkering with their engines.  

[Munkey]

Don't touch those 4 allen bolts.
You actually need to pull that rubber boot back where the swing arm meets the engine. Get a long flat head screw driver and pry back the cv joint under that rubber boot. The cv joint is spring loaded. Once you have it back, stick a screw driver in the hole in the middle of the swing arm bolt that you can see in this pic. The screw driver in the bolt will hold the cv joint back in its place, out of the way.

How far back does the cv joint have to slide? I've only been able to get mine to go back about a half an inch before the scredriver slips off. I am able to get the one in the hole to hold it at that point, but not sure if that's enough.

[SmokinFast]

...
On another note...I am kind of paralleling you. I am rebuilding one of my spare 750s engines that has very low millage on it. ...

Two more to add -- HappyCommuter and Munkey. Let engine fixing season begin!

How far back does the cv joint have to slide? I've only been able to get mine to go back about a half an inch before the scredriver slips off. I am able to get the one in the hole to hold it at that point, but not sure if that's enough.

That should be good enough.

After I found out that the drive gear just slides out, my engine removal was relatively easy.

Heres how I did it:
1) Remove the cylinder head if you want to make it lighter.
2) Support the engine on a jack with a wooden block.
3) After removing all the engine mounting bolts, take off all the frame brackets too. They will get in the way if you don't.
4) Place a cushion on the right side of the bike to let the engine roll onto when its coming out. I used a big block of styrofoam. An old mattress, packing material, or a couple of pillows would work too.
5) Raise the engine with the floor jack an inch or two. Rotate the engine to the right about 20 degrees (clockwise as viewed from above). If the final drive gear gets hung up on the universal joint, a pry bar will set it free.
6) With the final drive gear separated, roll the engine (bottom over top) out of the frame and onto the cushion.

[hppants]

Canuck spray.jpg?   

Fishmeister - you are nothing if not entertaining.

That notwithstanding, great information on this thread.  When my time comes, I hope I have enough courage to use it.

[SmokinFast]

Canuck spray.jpg?   

Fishmeister - you are nothing if not entertaining.

That notwithstanding, great information on this thread.  When my time comes, I hope I have enough courage to use it.

I admit I'm a bit slow sometimes, but I don't get it? Maybe someone deleted their post here?

... My engine (complete with a good alternator chain) should be ready to go back in this weekend. So I'll be attempting this procedure in reverse.

I've heard that its difficult to line up the engine with the drive shaft spline. I'm thinking that if I turn the rear wheel it should pop into place, no?

[Munkey]

I've heard that its difficult to line up the engine with the drive shaft spline. I'm thinking that if I turn the rear wheel it should pop into place, no?

I got mine back in. It was a small struggle to get the splines lined up right but I did what you said. I turned the wheel back and forth while pushing on the joint with a screwdriver for a few minutes until it finally dropped onto the shaft. Wasn't easy but wasn't too hard either.

[gammer]

I've heard that its difficult to line up the engine with the drive shaft spline. I'm thinking that if I turn the rear wheel it should pop into place, no?

I got mine back in. It was a small struggle to get the splines lined up right but I did what you said. I turned the wheel back and forth while pushing on the joint with a screwdriver for a few minutes until it finally dropped onto the shaft. Wasn't easy but wasn't too hard either.

+1
Basically thats it.

Update on my 85 engine rebuild:
I have all my parts in stock...got the cyl and head back from the machinist. I'll be putting the bottom end back together this week/weekend. I hope maybe I'll have the new engine in the bike next week...hopefully.

[OhCrap]

Awesome thread this is becoming, I'm bookmarking this for future reference.

Please keep us updated along the way & good luck getting the job done!

[vinimack720]

Hey guys I am in the process of removing my 86 engine and installing a working 84.  The manual says i need to completely remove the clutch slave cylinder, is this true?  Or can I just disconnect the hydraulic lines?

[gammer]

Hi vinimack720 and  

Got any pics of your bike   ??
Where are you located?

No, you don't need to remove the clutch slave cyl. Just disconnect the line going to it. Be sure to protect the engine parts from the brake fluid that will leak out of the line when you disconnect it. As you know that fluid will eat through any paint.
Are you sure the clutch slave cyl on the 84 engine is working correctly?
Also, what is wrong with the 86 engine?

Sorry for all the questions...it just gives us a better idea of whats going on.

[vinimack720]

well long story short:  My 86 with 50k on the clock started making top end noise that sounded like the timing chain.  It got really loud, so i tore it down with the goal of replacing the tensioner.  When i took the tensioner out i discovered that the tensioner looked perfectly fine, which lead me to believe that the chain had stretched.  And to replace that as you know would involve almost completely disassembling the engine, and I was unsure if any used chain I bought would be any better than what I have, and also the transmission was a little rough going into first and second.  So I bought an 84 parts bike with a claimed good engine for $150 and am currently swapping the engines. 

[gammer]

And to replace that as you know would involve almost completely disassembling the engine, and I was unsure if any used chain I bought would be any better than what I have

Just so you know, you can change the chain without taking the engine completely apart. I did it on mine last summer. Here is a link here that briefly describes that project: Click here

Also, you can purchase new cam chains. The same chains were used in the 91-02 Nighthawk 750's. Here is a link to a new after market cam chain: Click here

[vinimack720]

Yea i know that now after reading your threads.  But im so far into this i might as well commit to the engine swap because this engine was rebuilt 2k miles ago.  While it is in I may start a rebuild using your chain changing methods.  Question, what size is the allen bolt that holds the universal joint?  14mm?

[SmokinFast]

Yea i know that now after reading your threads.  But im so far into this i might as well commit to the engine swap because this engine was rebuilt 2k miles ago.  While it is in I may start a rebuild using your chain changing methods.  Question, what size is the allen bolt that holds the universal joint?  14mm?

I don't think you need to remove that 14mm allen bolt. After you remove all the engine mounting bolts, the engine just slides off the spline in the U-Joint.

Also, have you done a compression test on that '84 engine? Its real easy to test with the engine out of the bike. Just hook up a battery to the starter motor. I used a jumper cable from a car. The positive goes on the starter and the negative to the engine ground wire. After measuring around 150-160 PSI compression, I knew I was transplanting a good engine. But I decided to replace the cylinder jugs because the outside fins were broken off in a few places.

As for my engine, I got the pistons inside the cylinder jugs today and will be putting the engine in the bike tomorrow.  Once its mounted on the frame, I'll put the cylinder head on.

[vinimack720]

Yes i do not think it is necessary to remove the bolt, but it will make things easier because i will be able to put a screw driver through the hole to keep the spring loaded u joint held back further considering there is not a lot of room to move the engine around.  Is it a 14mm?

[SmokinFast]

Yes i do not think it is necessary to remove the bolt, but it will make things easier because i will be able to put a screw driver through the hole to keep the spring loaded u joint held back further considering there is not a lot of room to move the engine around.  Is it a 14mm?

There is a hole in the center of the allen bolt that is big enough for a screw driver to fit through.

The engine comes out (and goes back in easier) if you remove all the mounting brackets. Also, it was easier for me to take the engine out the right hand side of the bike.

... Well today I put my engine back in. I got the drive shaft spline lined up first and it went fairly well. I spent the most time with the engine mounts and getting the bolts in.  Tomorrow the cylinder head goes on.

[Munkey]

Tomorrow the cylinder head goes on.

Getting that back cam chain guide to go into place while you lower the head is a little tricky. I found that if you lift the guide up slightly and pull it towards the front of the engine an inch or so, it should drop back into place as the head goes down. Might take a couple of tries to get it right.

[Munkey]

The only thing that has me worried is whether or not the transmission is OK. Right now the shift lever is jammed, but I'm hoping it will cure itself when I get the engine turning over.

That's a little scary.