Removing starter chain guide

So I want to replace the starter chain guide, I understand that the crank has to come out but is there a way to do it without removing the timing chain? 1982 Maxim 750.

 

You can split the crankcases (leave timing chain where it is) without stripping the top end of the engine to replace the starter chain guide. If you wanted to replace the starter chain that would involve a complete engine strip. Here is a good guide from another member of the forum showing the cases split.


https://xjbikes.com/forums/threads/xj750-engine-removal-and-split-pictures.38545/

 

Correct me if I'm wrong but the timing chain is wrapped around the crankshaft so I won't be able to lift the crank without removing the timing chain thus I can't remove the starter chain guide

 

Yes the timing chain goes round the crankshaft sprocket and the starter chain goes round the crankshaft on an adjacent sprocket. You do not have to move the crankshaft at all to replace the starter chain guide as I stated the crankshaft only has to be moved if you are replacing an endless cam chain and or the starter chain. You strip out the engine covers, clutch, pickup coils and timing plate on the end of the crankshaft and the gear selector mechanism. There are four peened over bolts inside the driveshaft housing be careful removing those. Also heat the small bolts that hold the starter chain guide to the crankcase to soften the locktite as these bolts are easily damaged. If you don't have one get a workshop manual for your bike. You turn the engine upside down and take the bottom case off the top one. Some of the crankcase bolts are inside the oil pan and there is one inside the oil filter opening in the crankcase. Some of the components will remain in the upper case when you remove it. You need to remove the gearbox mainshaft if I remember correctly and the starter clutch and replace the starter clutch springs, plungers and dowels too when you are in there as it is a lot of work to do again if it fails.

 

Alright well I tried to get the guide out without removing the crank and it will not budge it gets caught on the chain and won't come out.

 

I have the 900 f hopefully you will be able to get it without removing the crank that's unfortunate.

 

Agreed. I always see it recommended when splitting the cases so I figured it wouldn't require a full engine teardown.

 

Let us know how you get on with the guide replacement good luck.

 

If replacing the guide means tearing the engine all the way down I'm not replacing it. I don't see any cracks in it and can't feel any on the ribs underneath. A full engine teardown is farther than I want to take it with this bike.

 

They break up and small bits of the guide get into the selector drum and prevent gear changes usually after approx 25 to 30 years. They fail due to age not miles.

If there is no signs of deterioration l wonder if it's the original guide? No way of knowing for sure.

 

Well I guess let me ask this...what is involved if the Pistons have to come out, any honing of the bores? How hard is it to get the timing back correct? This is the first time I've ever been this deep In an engine and I have to admit I'm a little intimidated. I've also never owned a motorcycle so I must admit that my itch to get it going so I can ride is there as well.

 

You should not need to hone the bores and the timing is not difficult. If you have a workshop manual that explains the timing and there are many people on this forum who will help you. It is a bit intimidating if you have not done it but you have already split the crankcases so with a manual and help from us you will be able to do it.

 

Thanks for the encouragement, unless someone else replies with a way to remove it without tearing the whole thing down then I'll have to get a workshop manual and I guess I'll attempt it!

 

You need a workshop manual. Crankcase and other bolts have to be torqued down in the correct sequence you need those specs and a torque wrench. Your braver than me l wouldn't take an engine apart without a manual.

 

Well I've been using a Haynes manual and it's been pretty good to get me this far. I've bagged and tagged everything and taken lots of pictures of how things are supposed to be assembled. For the torque values I would prefer to have that workshop manual just bc I know it's not uncommon for their to be mistakes in the Haynes.

 

I misunderstood l didn't realize you had a Haynes manual. I have a Haynes for my 900 and it explains how to set the timing marks on the crankshaft T mark and camshaft marks.

 

I had an idea, I wonder if I could remove the cam chain auto tensioner which might give me enough play in the chain to slip it off the crank sprocket. I could then remove the crankshaft and lift it just a little bit and slide the guide out.

For reference, here is what I see...

 

Don't move the cam chain off the sprocket that's keeping your valve timing. Leave the tensioner on the engine now your picture explains it. You need to remove the alternator shaft as the chain is round the starter clutch sprocket. Once you remove that you should be able to access the guide bolt under the chain.

 

Your crankshaft journals are in great condition.

 

That was an old picture, I just wanted to show you the timing chain situation. Here is some pictures I just took now...



I've already taken the guide bolts out, the problem is I can get the guide to almost come out but it seems to not be enough of a gap between the chain and the guide that will let it slide out. Sorry top picture isn't new, thought it was.