Cyoool!!!
I’d love to see video of your road test.
I’d love to see video of your road test.
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XS 850 Re Model
- Thread starter Signal
- Start date
Eugene, thats looking good. The black with red speed blocks is one of my favourite colour combos. You also have nice brakes, and it looks like a Yoshi pipe and I think I can almost make out that you have some Mikuni RS carbs.
Also like the single face dual dial speedo /tach unit.
Let us know how it goes. and thanks for the encouragement.
Back to my current problem.
As you can see in the photo the pin had been well and truly rogered. So after reading on the interweb a thread that you may be familiar with Eugene my plan is to drill a hole 180 opposite the old one and cut another slot in the advance unit.
First I dug up a XS 750 crank and got the pin out, luckily it was still proud of the surface. Long nose pliers skidded off so I used some heat (about 1 minute of mapp gas) and magnets and it slid out easily.
With a small dremel grinder I cleaned up the area of the snapped pin and blued it so I can see the remains of the old pin .
I have now started to make a drill guide for the new hole, it has a slot to locate over the old hole and will have a hole to drill through 180 degrees opposite.
The crank material is reasonably hard so I will get some carbide drills to give me the best chance of succeeding.
Then I need to cut a slot 180 degrees opposite the existing one in the ATU. I will epoxy the old slot so I can't install it in the wrong position.
Then need to check the timing marks and move the TDC pointer if needed.
Before all this started I had finished thw number plate mount and stripped the bike down to a frame and motor ready for cleanup .
I will then do a leak down test, and check that the 750 inlet cam will fit. I found some info on the 750 cams that makes me hopeful but want to try it before I strip the motor.
I also need to make a puller to get the driveshaft out of the swing arm. This bike just keeps giving.
Also like the single face dual dial speedo /tach unit.
Let us know how it goes. and thanks for the encouragement.
Back to my current problem.
As you can see in the photo the pin had been well and truly rogered. So after reading on the interweb a thread that you may be familiar with Eugene my plan is to drill a hole 180 opposite the old one and cut another slot in the advance unit.
First I dug up a XS 750 crank and got the pin out, luckily it was still proud of the surface. Long nose pliers skidded off so I used some heat (about 1 minute of mapp gas) and magnets and it slid out easily.
With a small dremel grinder I cleaned up the area of the snapped pin and blued it so I can see the remains of the old pin .
I have now started to make a drill guide for the new hole, it has a slot to locate over the old hole and will have a hole to drill through 180 degrees opposite.
The crank material is reasonably hard so I will get some carbide drills to give me the best chance of succeeding.
Then I need to cut a slot 180 degrees opposite the existing one in the ATU. I will epoxy the old slot so I can't install it in the wrong position.
Then need to check the timing marks and move the TDC pointer if needed.
Before all this started I had finished thw number plate mount and stripped the bike down to a frame and motor ready for cleanup .
I will then do a leak down test, and check that the 750 inlet cam will fit. I found some info on the 750 cams that makes me hopeful but want to try it before I strip the motor.
I also need to make a puller to get the driveshaft out of the swing arm. This bike just keeps giving.
Spark erosion is often a good, if slow solution to removing hard difficult to access parts. Sometimes it's the only viable solution. Not something you can do at home. Just a thought passing through my head.
She’s keeping you busy.
I looked at that option of the 180 swop. If the dremmel grinding hadn’t worked that’s where I was heading. My engineering skills aren’t in your league so the easiest solutions are usually my go to options.
Drive shaft shouldn’t get stuck in swing arm. Is it off the rear drive?
I looked at that option of the 180 swop. If the dremmel grinding hadn’t worked that’s where I was heading. My engineering skills aren’t in your league so the easiest solutions are usually my go to options.
Drive shaft shouldn’t get stuck in swing arm. Is it off the rear drive?
someone’s certainly had a right old go at it and buggered it up good and proper. It’s hard to even see the old pin.
The drill guide worked and the dowel is now 180 degrees opposite.
I was able to drill the crank without buying carbide drills however recutting the slot in the advance unit was more difficult.
The material was very hard so had to grind the slot but it all worked. Just need to recheck the timing pointer is still correct but will do this when the motor is painted and reassembled.
I have done a leakdown test and as far as I can tell its good with results well into the green sector and little variation between cylinders.
I may not go ahead with the 896 plan.
Had time to set the 750 inlet cam up in the mill and remark the timing dot 180 degrees from the inlet mark timing mark. Interestingly the 750 cam sprocket has 3 dowel holes spaced 1 tooth apart whereas the 850 cam has one dowel hole.
I also made an adaptor so I can put my degree wheel on the alternator rotor , not sure if it will be needed but I will then be able to check the timing marks are accurate and i feel better about turning the crank with the alternator securing bolt.
After dinner started to watch this again for info.
Found another small job to do- make a crankcase breather filter holder. No a biggy will mount it off a crankcase bolt.
Need to get some zip lock bags and plastic boxes to hold the motor internals during the motor strip.
I was able to drill the crank without buying carbide drills however recutting the slot in the advance unit was more difficult.
The material was very hard so had to grind the slot but it all worked. Just need to recheck the timing pointer is still correct but will do this when the motor is painted and reassembled.
I have done a leakdown test and as far as I can tell its good with results well into the green sector and little variation between cylinders.
I may not go ahead with the 896 plan.
Had time to set the 750 inlet cam up in the mill and remark the timing dot 180 degrees from the inlet mark timing mark. Interestingly the 750 cam sprocket has 3 dowel holes spaced 1 tooth apart whereas the 850 cam has one dowel hole.
I also made an adaptor so I can put my degree wheel on the alternator rotor , not sure if it will be needed but I will then be able to check the timing marks are accurate and i feel better about turning the crank with the alternator securing bolt.
After dinner started to watch this again for info.
Found another small job to do- make a crankcase breather filter holder. No a biggy will mount it off a crankcase bolt.
Need to get some zip lock bags and plastic boxes to hold the motor internals during the motor strip.
The motor is now apart, it was quite a job. Found a few unpleasant surprises nothing that money and time cant fix though.
I bought some plastic storage boxes and some wire cages that fit inside and a ton of zip lock bags. All the internals are now mostly stacked away.
The 850 is good to work on as you can take the top end off with the the motor in the frame which is good because the motor is a porker.
When taking off the sump the strainer was clogged so at least that works.
Also in the sump found the head of a sheared bolt and could not find where it came from.
The rods are pretty shot almost all of the copper has worn off the inside of the little ends, new ones are available but very expensive. The bore is on its first oversize . Still ruminating on the 896 kit.
Also found the starter bendix gear was worn (et tu 850).
When taking the transmission out the manual reads something like remove the bolt and take of the gear to withdraw the shaft. I could not see a nut to undo and the manual is in places a bit vague. I found the rest of the bolt sheared off flush in the shaft.
I don't think the gear could become jammed in use but if it did it would lock the back wheel the thought of it sent a shiver through me.
I have another starter gear and transmission shaft if my plan to get the sheared bolt out fails so apart from time no real cost except the rods which will more than make up for it.
The next little while will be spent cleaning and prep for painting the motor and plating stuff also going to build a platen for the head to fit on the flow bench.
A little bit of welding to finish on the frame and that can also be blasted and painted.
I bought some plastic storage boxes and some wire cages that fit inside and a ton of zip lock bags. All the internals are now mostly stacked away.
The 850 is good to work on as you can take the top end off with the the motor in the frame which is good because the motor is a porker.
When taking off the sump the strainer was clogged so at least that works.
Also in the sump found the head of a sheared bolt and could not find where it came from.
The rods are pretty shot almost all of the copper has worn off the inside of the little ends, new ones are available but very expensive. The bore is on its first oversize . Still ruminating on the 896 kit.
Also found the starter bendix gear was worn (et tu 850).
When taking the transmission out the manual reads something like remove the bolt and take of the gear to withdraw the shaft. I could not see a nut to undo and the manual is in places a bit vague. I found the rest of the bolt sheared off flush in the shaft.
I don't think the gear could become jammed in use but if it did it would lock the back wheel the thought of it sent a shiver through me.
I have another starter gear and transmission shaft if my plan to get the sheared bolt out fails so apart from time no real cost except the rods which will more than make up for it.
The next little while will be spent cleaning and prep for painting the motor and plating stuff also going to build a platen for the head to fit on the flow bench.
A little bit of welding to finish on the frame and that can also be blasted and painted.
