1981 Virago 750

I can't stay away from project bikes and this winter is no different. I pick up a (lot) of bikes when I was only looking for one. Yes the seller talked me into the lot of five bikes, four with titles and one parts bike.

The first one I dove into was a 1985 Virago 700, more or less straight forward with all the refreshing on that bike. Carbs, ect...

The starter clutch gear, well parts in the mail.

So to the Virago 750.
DSCN0005 by Tim Brown, on Flickr
Seller said this was a parts bike, the PO said that it has dropped a chain off one of the OHV's. After pulling the plugs out and rotating the engine by hand, there was no compression to be found. Pistons were moving just fine and no binding. Had to pull the OHV timing covers off.
DSCN0014 by Tim Brown, on Flickr
So the engine is done, but that is not a bad thing, good carbs and lots of metric bolts to salvage. I wanted to see what this starter clutch gear looked like, so pulled the cover. I found some nasty stuff.
DSCN0012 by Tim Brown, on Flickr
DSCN0013 by Tim Brown, on Flickr
DSCN0016 by Tim Brown, on Flickr
Not only had the rear chain broken in two places, the front exhaust valve spring cover or washer had broken as well.
DSCN0017 by Tim Brown, on Flickr
I know this is a long first post but just wanted to show all the stuff you don't want to find in a engine and a bike refresh. Good news is I have a donor motor that I just have to pull out of a chopped frame and swap them out. You know it will not be that easy...come on. lol

 

What idiot touched that last?

 

It took some serious effort to blow one up that badly. I wonder if they were trying to test the rev limits? At least is it clean, broken but clean. Yes, sometimes we have to stretch to find the positives.....
John

 

For the price it still was a good deal. 2 Honda Magna 750's, 1 Virago 700 and 2 Viago 750's. Got all the bikes for the price of one running bike. He needed the room in his garage, so it was good timing for the both of us.

I just thought I would share the engine swap on this one with the board. Going to do some reading today and see if I need to support the frame in any special way to remove the engine. I have the ability to hang ratchet straps from the rafters in case I have to support frame.

 

Was able to take advantage of a warm day here in Wisconsin. Got two motors pulled and stopped at putting the good motor in titled frame. I didn't want to push my luck.

If anyone ever does this in the future the book is wrong. It tells you to take out the screws on the engine side of the driveshaft. It is wrong, that only holds a plate and has nothing to do with spline alignment on the driveshaft.
This is the donor bike, don't you love how someone cut the front end off the bike. I would guess it was a junk yard bike and from the right side pipe scrapes it has been in a crash. I would guess the front end was messed up and so they cut it off.
DSCN0018 by Tim Brown, on Flickr
The engine came out of the donor a little hard, getting it to away from the driveshaft. The titled bike, the junk engine came out nice. I thought it might have been just getting the used to it from the first one. It just seems like a much better taken care of bike with less rust and junk.
DSCN0020 by Tim Brown, on Flickr
I thought I had better call it a day with both engines out. I should take advantage of the donor motor being out and do the valves with the easy asses. I did test the donor engine before I pulled it. Turned it by hand and both pistons moved with good "feeling" compression. I didn't test the compression, just had plugs in lose.
DOA motor on left with side cover off, donor motor up front ready for some TLC.
DSCN0019 by Tim Brown, on Flickr

 

Another good weather day, so the engine went back it nicely, not one curse word was said. Put the rear sets on the bike (this holds the back frame to the engine and front of frame, and moved the bike back to a warm table.

Did the valves, 3 were out of tolerance, cleaned up the covers while I had them off. Checked timing all looks good. Plugged in all the connectors, put jumpers on the bike and turned the key. Hear a relay so that was good. Start button is frozen but was able to jump the solenoid and the starter works! For those that don't know about the starter clutch gear on these bikes, they are terrible. Engine turned over well, front compression was 120 back was not that. I am hoping that rings are frozen and will soak them a few days. I do have spark that is half the battle. On to the carbs today if I wand to drive on snow covered icy roads....hmm.

Got on the Virago forum finally and chatted about the starter gear. Seems most of the Virago people just use a SS hose clamp to put more force on clip #2 in the starer clutch diagram. They also take either a cutting wheel or a dremel and remove the rounded portions of the gear face that slams into thew fly wheel as the best fix. I have the new starter gear coming but for $200 is it really worth it on these older bikes?

 

Looking forward to your pics of this. A buddy rode this same bike back in the 80's and I always had a laugh when he pressed the starter. I'm curios to see what goes on there.

 

No pinched fingers? No scuffed knuckles? Wow, I am impressed but wondering what was forgotten. An engine in and not a single cussing, that isn't right. Good on you if you could do it though, I have heard of such things but never experienced it.
John

 

Here is the new superseded part that is offered. I have one coming of the VX700.

 

Here here is a pic of the old nasty starter gear on the left. It is very rounded compared to the one of the right. I tired to point out the new cuts to take the rounding off the front of the gears.
gear by Tim Brown, on Flickr
The plastic buffer was also party ground off or broken so that was filed off.

This is my attempt at patching a crack in the "custom" exhaust that is on the bike. The baffles is a large washer welded at a angle 5" from the end of each pipe. This bike will be loud.
20210205_123409 by Tim Brown, on Flickr
20210205_124618 by Tim Brown, on Flickr
Carbs parts are soaking and exhaust is working up in the shop. Would like to paint the exhaust and have it on when I try to start the old gal.

 

Worked on the carbs a bit, the donor engines carbs that is. Noting too nasty in them, just the normal varnish but the slide pin was so stuck in one, had to remover the emulation tube and soak them together. Chokes were really nasty, not used to seeking the choke ares so full of old gas and varnish, might be a Vtwin thing. The enrichment jet in the bottom of the bowls are also very plugged. They are still soaking as I had not luck with the bread tie wire and compressed air. I do have two other sets of the 750 carbs that came with the lot I purchased. I think I will see if the float bowls are any better.

 

Been cleaning and painting the exhaust, back on the bike. Removed the rear tire to inspect rear hub, looks good. Brakes are new on the back so that is one less thing. Cleaned the left side cover from all the RTV that was used. It is strange all the RTV with a new good gasket on the cover too. Engine is still oily from PO, not too sure but I think it was coming from the valve covers and leaking down.

Got the superseded starter gear in hand, will post some pics of the new and the old before I put it in the bike. That is going in the 700 as the 750 seems to have a good OEM starter gear.

 

Does that operate the same way as a Bendix setup of a car?

 

Yes but with more moving parts.
DSCN0021 by Tim Brown, on Flickr
This is the part and number...
DSCN0022 by Tim Brown, on Flickr
Old left new right.
DSCN0023 by Tim Brown, on Flickr
Well I am not too sure that this is the right part for this bike. I thought I looked it up and it will fit a 1985 700, well I tired for a while and had to wold away from the project for a bit. The cover would not go on with the new part.
After switching back to the old gear but with the shaved mod and the one coil of the spring cut, the starter worked just find. I hit the starter with and the bike not only turned over right away, but started right up. I didn't have oil in it so had to kill it right away. So, the mod fix works just don't know for how long.

 

The damage to the pinion I have the same problem on a car at the moment when the engine fires the pinion is not retracting fast enough and grinding on the flywheel ring gear. A bit of difference in the angle of the splines on your new parts hopefully that will fix it.

 

Having some issues getting the 9mm hex bolt out of the bottom of the forks. Any advice? If I remember, taking a long wood broom handle and wedging it down there might work. I think in the past I have had to drill many out and just replace the 9mm hex after the rebuild. What have you guys and gals done to remove the bottom fork bolt?

 

The real Bendix system (which the rest of the world got from the beginning) requires parts from the US XV1000 or 1100. Notably the case cover as well as the gears.

 

Patience and rage
Put the fork back together, and then loosen (but do not remove) the lower bolt. The spring pressure will make a huge difference.

 

Thanks k=moe already tried that, put them back together but the inside lower is still spinning. I will try the wood dowel jam trick. If that does not work I have a good drill bit collection and will just drill them out. You got to love the smell of 40 yrs old fork oil. Good think nit was very cold today so the scent was lower. Have them upside down draining all night, will give them a try again tomorrow.

I think I have some of the metric keys that would work if the lower portion was cast with a bolt or what ever mm hex key was needed. I don't think the older ones had any factory key size on them. So jamming a wood handle down there with pressure and try. I also so one vid, they cut the wood handle the same size as the internals to the cap. The cap was screwed back on tight and it provided the pressure to hold the internals. Might give them both a try.

 

Does the Virago have fork internals similar to the XJ650? I used a bolt on the end of a socket to hold the lower internals in position. Let me know if you want bolt size.

 

Brent,
I hope it does, I could not see the shape of the top yesterday. I have a tool made for doing other forks so I will try that today and see what happens. Nice out this morning -14, ya, I will hold off going to the shop for a while.

 

Just found a good article for the fork tubes... the top of the inside is a 19mm pitting that a 19mm bolt should fit.
https://www.viragohelp.com/virago-suspension-systems/

 

Mother nature has won today. I attempted to get the lowers separated today. Between how stubborn the bottom bolt is being and just how cold it was to work with those solid steel forks, I had to give it up. I tried finding a nut to fit down inside to stop from turning. I ran out of size at 24mm and that didn't work. I tired the handle down the inside trick, I broke 2" of the wood inside the lower from the impact hammer. Next I guess I will have to drill it out, but that had to wait on another day, too cold out.

 

I seem to remember doing a set of forks, maybe the Seca 750 and using a spark plug socket to remove the damper rod. The spark plug socket has to be 1 with the hex on the top. Fit the 3/8" drive extensions from the spark plug side so that the hex can fit into the damper in the bottom of the fork slider. If you have enough extensions you can get your breaker bar on the top and allen key on the bolt in the bottom, add a little heat to the bottom if possible and you should have enough leverage the get it apart. Of course in your neighborhood any heat is just going to be sucked away so quickly it won't matter right now.
Good Luck!
John

 

Nice weather again today, but chose to get this fork thing done. Ended up having to drill both of the bottom bolts out. Not hard once you just go for it. Once I got the first one apart I measured the top of the internal fork and it looks to be a 26mm.
20210213_131950 by Tim Brown, on Flickr
As mentioned by Fuller56 above ^, one of my old motorcycle tool kit wrenches did fix okay. Not a perfect fit, but for future reference I might try it once before I drill the bolts out again.
20210213_132021 by Tim Brown, on Flickr
This is how I had to hold the inside so it would not spin as I drilled. I think this wold work better as a two person job. I did use the vise the second time around to hold the stick and work my way up to a 9mm drill bit.
20210213_121517 by Tim Brown, on Flickr
If you chose to drill out the bottom bolt on these older bikes. Take it slow, work your way up on the drill bit size and use a center punch once you are down 1/4" or so. You do the measuring yourself on another bolt but not that far. Breaking the bolt off at the end with a center punch will make sure you don't damage the fork lower. You will have to drill over an inch to get to the internal lower part.
This worked on this fork.
20210213_132339 by Tim Brown, on Flickr
Good luck if you are rebuilding the forks and for those of use in the cold snap, stay out of the wind and stay safe.

 

Yamaha (among others) used Threebond to secure the damper rod bolt in place. They don't always come out easily, even with the proper tool to hold the damper rod.

Also, if you need to drill the head off, use a left-twist drill. The damper rod is less likely to spin on you, and sometimes you get lucky and the bolt twists itself out.

 

Worked on the lowers on the forks. Got all the old stuff off them and have them put back together with new seals. End bolts in the mail to finish the job. Installed the newly painted exhaust on the 750. Inspected the rear break shoes and put back tire on. Carb gaskets came in the mail so once the temps get above 0, head back to the shop. Hope to hear the 750 run today. Need to hope the shop doors for that so need some warmer temps. Next will be getting to the bar switches, starter button, headlight and gauge reinstall.

 

Have the gas tank sitting with evaoprust i it just to make sure. I have ordered the on/off/res non vacuum petcocks and will have to do the mod on one of them. Removing the fuel nipple from the petcock, drilling through and then steal weld epoxy the original side. I like the full on and off type petcocks just to be sure.

 

Finished modding the new fuel petcocks. The 750 has two of them so had to remove the output fuel nipple, drill through the petcock fuel hole, steel epoxy the original end then reinstall fuel nipple on the other side. I found a link once but not right now, I would share it.

Got the 700 running but the front carb was not working right. I took the carbs back off and sure enough some fuel line rubber had blocked the bowel fill jet. That was a first for me. New fuel line, cleaned carbs again, nothing else found. Installed carbs and ready to put AUX fuel and start it again. Live is getting in the way again.

 

Front cylinder issue was the float level. Always remember the basics when you are trouble shooting. It will keep you from second guessing what you know and have tested. The compression on both cylinders was 150. They had spark and still the front cylinder would not run. Pulled the carb boots off and put my hand in front of the opening of the front cylinder and it started to fire and then run.

When I fixed that the carb gasket on one of the carbs broke. Back to waiting on the mail. I guess I will take the ignition out of the new project bike and make a key for it.

 

Are you member at
viragotechforums.com ?
The members there were very helpful when I was refurbishing a 920 for a friend and the 920 project that I had to sell before moving (still annoyed that I didn't have room to take it with me)
It's not as active a forum as we are, but there are tons of great articles and threads.

 

Yes I did get in over there. Thanks for the heads up. Once of the folks over there is active and tries to help out. Lots of links and data to sift through.

 

The 4 brush starter came in, need to take the time to put it in and see of this bike runs. Really hoping I can save the left side cover gasket.... Need to get this bike down the road and find it a good home. Spring is in the air and lots of folks looking for bikes.

 

If you can’t save the gasket cut one from a cereal box and spray it with gasket dressing.

 

Took me over an hr to get that side cover off! Wow was that thing more or less rusted on. The two dowels were more or less frozen in place. Took another hr to get the gasket off the cover, I am sure it was OEM.

New 4 brush starter in, shaved the teeth on the starter clutch gear with dremmel. Got her all buttoned back up and tried to start it....my jump start battery was not charged, so I will have to wait till morning.

Changing out the gasket on the 700 s well, have that sitting overnight with some gasket removal stuff on it. I don't know if that will really work but have to try. Going to put the new and improved starter clutch gear in the 700 and hope it work well.

 

The 750 has a bad rear head gasket, so she will not run. I did get the starter figured out and it wants to start but not enough compression on the rear cylinder. I will wait maybe till the end of summer to pull the motor our again. Oh well when you see bubbles coming out of the head that is not good....lol.

 

Bubbles?

 

Yes just as the fuel was being squeezed out of the cylinder head. I just say one, not like a bubble bath or anything going on. There was also a tell as it was oily or dirty in that area as well. Just never know on the rear cylinders as they always seem to be dirty. Once I catch up on other projects and move some of the winter bikes on down the road, I will get back to this bike and make her work.

 

Found a donor bike for cheap, going to pick it up tomorrow and hope to swap the engine out. The donor bike also has a nice back rest that looks nice. So this will be the second motor swap out to a title frame for this 750.

 

Pulled the donor engine this afternoon. Looks like the back cylinder is also low on compression. No gasket leaks and the engine only has 13K on it. Older engine was 26K. I am hoping it is a held up rings and will take care of it's self. If not, taking the engine out does not take the long. I will pull the engine out that has blown head and see what can be done to that one. I would hope I can pull the head off and replace the gasket. If nothing else, I can hone and see if the rings are still in tolerance.

 

Found a common issues with the heads so far. There seems to be a weak spot.
DSCN0096 by Tim Brown, on Flickr
DSCN0095 by Tim Brown, on Flickr
Two different engines both 750s and the rear head. Almost the same place for the deterioration of the head. This is what the head gasket does.
DSCN0090 by Tim Brown, on Flickr
I have one good head that has a valve issue. Will have to sort that out and then see if I can get it to work.
DSCN0094 by Tim Brown, on Flickr
I will take some 100 grip sand paper to it and see if I can get it a little better.

 

Can you o-ring the head with a piece of copper wire as the old hot rodders used to do?

 

If a person wanted to put the time and money into one of these bikes you can. Here is a good vid of what some folks are doing to save these bikes. I guess the gen 1 head gaskets were just nasty. When they failed the engine eat the top end.

When you buy a new head gasket it is made of different material. Once I get the other bikes I have for sale out of the shed, I will try to save at least one of the blown engines. Yesterday I put in the good donor engine in the bike. 150 psi on both cylinders. Today I hope to get it running. I moved the bike without the engine in it, that shifted the frame a little and I had a heck of a time getting the new motor in the titled frame.

 

All is going well with the motor swap. The engine is a beast 150 psi both cylinders. The starter is a 4 brush cleaned and working great. Starter clutch gear has been re-shaped and engages very well. Now the issues, this motor has so much compression that even with a 800 cca battery and 2 gauge jumper cables, there is no starting this bike. The starter just can't spin motor fast enough to get it to fire and run. She hit compression stroke and stops, throws off some smoke from firing and that is it.

If I wanted to keep the bike I would take the heads off and put some compression relieve valves in them. I think that would be the best option for these old Gen 1's. I think it is time to find a new home. I have a title with it and I would guess I can at least break even. I have asked for help with what I might be doing wrong, I guess it is just the way these bikes were.

 

Don't know much about the Virago but I've have had high compression engine starting issues before.
Just a thought...
Have you done a voltage drop test?...perhaps the ground wire (from engine to chassis) should be a larger gauge wire, or maybe there's corrosion along the path.

 

I did a newbie thing and am just laughing at myself. I had the coil wires swapped....yes that was it. Changed the coil wires hit the starter button and it fired right up. I felt so stupid...just looking too hard and not sticking with the basics.

As for the starting, from what I have read the starter on all the Virago's need to be gone through and cleaned up. Most of the OEM/2 starters are 4 brush and really help with turning the engine over. Making sure the valves are set and all the rest (coil wires for 1 and 2 in correct plug) and the engine should fire right up.

The marble sound can be fixed if you take it on. Easy it is not, until you get used to it. I have done three now and it gets easy. The face of the starter clutch gear get "rounded". Taking a dremel with the cut off disk you can "sharpen" them back up to look better. That will really help the "marble" sound and basically eliminate it. Will it go away for ever, no, it is a bad engineering issue that was not fixed until the 2nd Gen bikes.

The donor bikes all nice parts have been changed over to the bike with a title now. It is starting to look good. The new starter relay came in the mail today and I need to get a good battery for it. Will be time to get that $164.oo new title and go from there.

 

Out of nowhere I now have a electric gremlin. It is in the headlight bucket and it is a lose wire. I have a new Probe III that I picked up, time to use it to see what is up with the lose wire. The bike starts and runs well now, as you drive it the vibration from the road or revs will cause a open to one of the relays in the rear of the bike. This new Probe III tool should make it easy to trace. I am so used to the old school multi meter, but a friend of mine that owns a shop showed me the Probe. I hope it makes things easy to find.

 

I’m kinda new to this forum but I have a 1981 Yamaha xv750 virago and I’m looking for original y-23 and y-22 carb slide needles for my carbs if anyone has any please lmk