2nd Gear Help Needed

My '83 XJ750 Maxim jumps out of 2nd gear. I am aware that this is not a rare problem.

I intend to fix it.

The engine must be removed, I'm sure.

Do I have to remove the cylinder head, cam chain, cylinders etc to get at the changing forks & changing drum?

Can I remove the bottom case & access the gear change mechanism without removing all of the above?

All help will be gratefully received

I have a 1 month time limit to do this...is that realistic?

OG

 

Old Goat, you don't need to pull the top end off to do the tranny. I would guess you can get the engine/transmission out of the frame without pulling the top end off. I can't imagine Yamaha finished assembling their engines in the frame.

Here is a link showing how to do 2nd gear without pulling the engine by turning the bike upside down.

http://www.xs11.com/forum/showthread.php?s=ff19c5da70d9fa072fd43717eb0d0cad&threadid=5090

 

MiCarl

You are my saviour.

What a truely helpful link.

Upside down the bike will go!

OG

 

Old Goat,

Something to think about. I'm not sure if you can get to the alternator chain guide or starter clutch through the bottom.

 

I've read the article & he does not mention that & his pics do not show it.

Remove shift mechanism from lhs
Remove clutch basket
Remove a cover or 2 that are exposed & the shift rod & gears can be removed sideways.

We will see!

 

starter clutch : yes
alternator chain guide : ?

 

My '83 XJ750 engine is constructed differently to the one pictured in the link.

My clutch basket has a large gear wheel riveted to the back of it. This gear wheel extends into the crankshaft area preventing the basket from pulling off the shaft.

I guess I'll have to remove the engine then the lower engine case to get access to the transmission.

Not even sure if the lower case comes off without removing the head, barrels etc. I will find out!

 

I took the engine out, turned it upside down, removed the oil pah.

Then discovered I did not need to have removed it. Could have turned the bike upside down after all :roll:

The gear shaft bearing was then tapped out from the inside. The one in the link had a flange on it & you could pull it out by its ears after removing the 3 bolts.

Ah well, you live & learn!

 

Sounds like you're making good progress. And by my count you still have 29 days left to work on it.

Do the primary chain guide and starter clutch while you're in there.

Polock, I was under the impression that calling this guide the primary chain drive was incorrect. I thought a primary chain was the chain driving the transmission which our bikes do using a gear. I see in the parts fiche that it is called GUIDE, UPPER, and the chain driving the alternator is indeed called CHAIN, PRIMARY. Sorry for the confusion.

 

I've got the first gear of the shaft. (called the 5th gear)

So far I have been unable to remove the shaft in order to get the rest of the gears off it.

Any ideas?

 

I don't think the transmissions on XJ Series Bikes come out without lifting them out as a unit after the cases are split.

I have never heard of anyone doind a gear job without having to split cases.

 

That's the answer I came to after sitting over it & puzzling for an hour.

Is it a big deal to remove the lower case?

I have the engine out of the bike & upside down

Do you think I have to just remove the bolts holding it to the upper case & gently tap it off?

 

If I remember correctly there are bolts on the bottom, on the top, and behind the oil filter cover that need to come out before the casing will split. You don't need to remove the cylinders.
Get a piece of cardboard and label all the bolts as you remove them as they are different lengths. If you look beside each bolt you will find a number to identify the tightening sequence.
There are two bolt sizes. 8mm bolt torque to 17.5 ft-lbs. 6mm bolt torque to 8.7 ft-lbs
16 bolts on the top case
21 bolts on the bottom case

 

Thanks Nick

 

If you have it torn down as far as you say Goat, splitting the case won't take but another dozen or so minutes. Remember, you DON'T have to yank the head do split the case. I took a sheet of cardboard and made a cutout of the top case and one of the lower case, punched holes in the templates and inserted the bolts into the corresponding location when I removed them. Saved a lot of grief later.

 

Robert, I wish I had thought of that. I ended up putting a piece of masking tape on each individual bolt and numbering it... it was a hassel.

 

Thanks all. I put the bolts in sandwich bags with the hole # written on them.

Cases apart, output shaft with its gear set out. Replacement input & output shaft purchased on ebay & on its way. Hope the dogs on 5th & 2nd are better than on the ones I have taken out.

I could not get the Allen headed bolt out of the LHS of the crankshaft, it holds the timing disc. Removed the 2 firing coils & the 2 small bolts that hold the gold coloured backplate on.

I had to force the lower case off at that point by deflecting that backplate as much as I could.

That black coloured Allen headed bolt sure is in there tight (I'm assuming it is a regular thread & not a left handed one). No idea how to get it out or wether I should even try :evil: It will make installing the lower case more difficult though.

Oh well, these things are sent to try us!

Can rest my bruised hands until the replacement gears arrive

 

You'll have a decision to make upon joining the cases once the transmission difficulty is taken care of.
You need to select a Sealant for those cases when rejoining them.
Although its messy and a bit of a pain to work with I have always bought a tube of Yamabond-4.
The gray stuff is oil tight and flexible. Makes a good, solid oil-tight bond.

Follow the instructions and get the Mating Surfaces nice and clean.
I have always taken the time to prepare the edges by razor blading off the residue and wiping them down with Alcohol to make them clean and dry for the application of Sealant.

I place Sealant on BOTH sides and let it "Marry" when the two sections are rejoined. The whole idea is to make it a permanent bond and get it sealed-up tight the first time around.

After the Cases are rejoined, I spend additional time torquing the bolts in incremental application of Torque.
I always clean the Bolt Threads by touching then to a spinning wire wheel to get them clean and shining.

I use Permatex Thread Locker and start tightening the pattern with low torque gradually increasing the torque until I reach specs.'
Using a Sears Craftsman Torque sensing wrench; I apply full Torque and seen to have to wait forever before feeling the tell-tale "Click-release" that the wrench provides upon reaching the dialed-in load.

In my view, the extra time spent joining the Cases is worth it for a No-Leak situation after the job is done.

 

Thanks Rick.

Not sure which sealant I will use yet but will definitely clean the mating areas thoroughly & lastly with alcohol.

I have an assortment of SnapOn torque wrenches. Most of them are the ones with a dial & cover a wide range of torque. I have one click type.

I have several types of sealant:

Permatex 1, form-a-gasket. Hard setting, quick drying. Resists oil
Permatex 2, form-a-gasket. Non hardening, remains flexible. Resists oil
Permatex ultra black, high temp RTV gasket maker. Not gas resistant
Permatex Adhesive Sealant. Black RTV silicone. Not this one I think.

Any suggestions? Or should I get the Yamabond-4?

OG

 

I don't know about anything other than the YamaBond.

I never used anything else.

 

My not being able to remove the 8mm bolt in the LHS end of the crankshaft that secured the timing plate & the plate that the firing coils are screwed to has been really bothering me.

I knew that when I came to replacing the lower crankcase I would have to force it past the coils securing plate & prevent me from cleanly just dropping the lower case on.

I had already deformed a 6mm Allen socket & the head of the bolt so I decided to bang a #45 Torx socket into the bolt head. This Torx socket did not slip in the bolt head but snapped in two when I tried to remove the bolt!!

There was still 1/2" of its hexagonal body protruding from the bolt head so I clamped a "huge" pipe wrench with a 24" handle extension onto the Torx stub & pulled & held my breath. They was a loud crack & the bolt came loose .

Hopefully that will be the end of my miseries but I'm sure there will be some more lurking around the corner. Like the replacement transmission gears being no better than the ones I removed.

 

Permatex markets a grey gasket sealant. I've used it as a Yama-bond replacement with great success. I'll post the numbers later.

 

Those stuck fasteners can set the job back for hours. Glad you managed to muscle it out.

You'll need to procure a replacement. I'd give the Dealership a heads-up if you need parts. Sometimes they have them ... sometimes they have to order.

It's when they have to order stuff that major delays happen.

 

what ever sealant you use, squirt what you think you'll need in the corner of a baggie then twist it a few times and snip the corner off and squeeze it out like a cake decoration

 

Thanks Rick, but I have boxes of all sizes of metric fasteners in several tensile strengths.

 

Neat idea, I'll give it a try

 

I have no earthly idea how they do the application of Sealant at the Factory to have it come-out so even and pretty.

But, I have always made sure that the two surfaces got a healthy bead of Sealant by squeezing it right on to the edges ... straight from the tube ... and getting a little messy by dabbing and spreading it even with my finger.

I'd rather have an overlap of Sealant "Show" than risk not having put enough on and having a leak.

 

http://tinyurl.com/49apa6

 

I'm getting ready to put my case back together (parts are coming tomorrow) and I'm scared about getting Yamabond inside the case. How bad would it be if a little got on the inside?

 

if some squeezes out between the cases, thats ok it'll setup there and stay just don't drip any blobs
when you come to a bolt hole go all the way around it
wipe the edges with a rag and some lacquer thinner
i only do one side of the case, i guess some people do both, either way clean is the word

 

Sorry Goat, here is the stuff I used.
Permatex® Ultra Grey® Rigid High-Torque RTV Silicone Gasket Maker.
Best of luck on your efforts.
I smear a light film on both sides of the cases and then just close up the assembly. With a light film, there shouldn't be enough to make a blobs big enough to worry about.

 

Thanks for the info Robert.

I have already bought some:

Permatex MotoSeal 1, Ultimate Gasket Maker, Grey.

Says it's for use on motorcycle crankcase halves & transmission case halves.

Sometimes they call the same thing by a different name in Canada, even though made by the same manufacturer.

 

I'd place my trust in Permatex.

I use quite a lot of their stuff. I'm sure it's going to Seal-it-up and not leak.

 

It's all back together again & running great.

I bought a used transmission from an ebay dealer (input shaft & gears, output shaft & gears, selector drum, selector forks & shift mechanism) for $25. He would not sell it to me as I live in Canada. Got a US friend to buy it (it was a "buy it now" item. Got it on Thursday.

The 2nd & 5th gears were light years better than mine. I installed the entire output shaft with its gears and his selector drum & shift forks.

Got it all back together last night. Even got the engine in by myself with the aid of 2 jacks. Not that difficult really. Had to remove it again partially as I had forgotten to put the driveshaft flange onto the driveshaft. I did have the other half on the rear of the engine.

Put the carbs & all the other fiddly bits on today & it started right up.

A trip round the block (it's not registered!) & the gear box worked beautifully. No popping out of 2nd gear

I did have one scare after I had installed the external gear shift lever. All the gears were backwards. Up for 1st & down for 2, 3, 4,& 5 :evil: :evil:
Minor panic. I rotated the coupling on the splined shaft 180° & all was well.

I had taken pics before I dismantled it all & should have consulted them before installing the shifter.

The neutral light did not work at first but did after a while.

I have never had a bike engine apart so completely before so it was all rather scary.

I believe I could now do it by turning the bike upside down or onto its right side as the transmission output shaft comes out of the sump after removing the end bearing & 2nd gear. It would certainly be a lot easier as you would not have to remove the engine or split the cases.

I've now sold the bike.

Thanks for all your input

OG

 

Sorry to hear it has found another home after all of your effort. I hope you directed the new owners here. Good job on the repair. I'll bet you had a grin a mile wide on that trip around the block.

 

Sold the bike???
Holy Cow!

After that job and a half ... I would have at least expected you to ride it for a little bit.

Hope you got your money's worth. I'm sure the new owner has!

 

I bought it as a winter project. I'm retired & enjoy working on bikes.

I put it up for sale 3 weeks ago & sold it to the 1st person to come & see it. Could have sold it 10 times over.

I had never actually ridden it on the road. Only had it running in the driveway. Went up & down through the gears just fine.

After the guy bought ( he couldn'it try it as it was not registered, was snowy & he had not yet passed his test) he asked to leave it in my garage for a week or so until the weather improved. I took it round the block later that week. It jumped out of 2nd gear.

Phoned the guy & told him I would refund his purchase price. He said he liked the bike & would it cost a lot to have a mechanic fix it. Told him it would cost more than he paid for it ($750)

He asked if I could fix it & said he would pay me. Told him I would fix it free as it was my fault. He said he would pay for the parts but I said we could go 50/50 on the parts.

Upshot of it all: it's fixed but I've aged quite a bit in doing it. He will pick it up this coming week sometime. A real gentleman of a buyer

I don't think I will buy another fixer upper for the winter. Too many intangibles.

 

You are a gentleman old goat. Not too many folks would worry themselves over a as-is-where-is sale. Your buyer sounds like a rare gem, I'm glad you treated him well. Did you pass along our site address to him?