1986 vs750 intruder rebuild

General questions not related to any bike specifically.
Every day questions, batteries, oil, spark plugs, etc. etc!
Think if it as the, Motorcycle Chit Chat Channel.
Kdp89
Tricycles are Cool
Posts: 16
Joined: Sun May 14, 2017 6:57 pm
My Bike: 1986 vs750

Re: 1986 vs750 intruder rebuild

Post by Kdp89 »

Ok, I'm slowly working my way through this after being on vacation last week.
I installed the new solenoid and all is good with the ignition circuit now. Push the start button and the bike turns over.
Next problem! That's all is does. The bike turns over and will occasionally give me a firy backfire since I don't have the muffler back on yet. It occasionally sounds like it might try to start but it never actually kicks.
I tested the coils and they are good. I also replaced the spark plugs and checked the spark and they will jump a good half inch gap. So spark isn't the issue.
Anything else to look into before I start tearing the carbs apart? I'm really not looking forward to that. But the bike has been sitting for quite some time.

Lechy
Joined a 1000cc Club
Posts: 3955
Joined: Tue Dec 09, 2014 9:58 pm
My Bike: VS800 Honda Phantom 200

Re: 1986 vs750 intruder rebuild

Post by Lechy »

Check to make sure your fuel pump is working, drain the float bowls (you might have to poke a bit of wire in the hole) if the pump is working and the bowls are empty the float valves will be stuck, a couple of taps with a hammer handle should free them. Next pull the air filters and check them over.
Then pull the carbs for cleaning.
[emoji41]
Grow old disgracefully young man.

Kdp89
Tricycles are Cool
Posts: 16
Joined: Sun May 14, 2017 6:57 pm
My Bike: 1986 vs750

Re: 1986 vs750 intruder rebuild

Post by Kdp89 »

Ok, well I am getting fuel to the carbs. Pump is working well. Turn it over for a bit and the bowls are full to drain. I pulled the air filter and they look ok. No build up or anything. Even still I am not getting any gas into the cylinders. I can crank it over then pull the plugs and they are bone dry. What do you think?

Kdp89
Tricycles are Cool
Posts: 16
Joined: Sun May 14, 2017 6:57 pm
My Bike: 1986 vs750

Re: 1986 vs750 intruder rebuild

Post by Kdp89 »

I also just tried a shot of ether into both carbs and got nothing. I'm starting to get frustrated with this one. It may be time to call in the mobile mechanic.

Lechy
Joined a 1000cc Club
Posts: 3955
Joined: Tue Dec 09, 2014 9:58 pm
My Bike: VS800 Honda Phantom 200

Re: 1986 vs750 intruder rebuild

Post by Lechy »

Rear carb, RH side, black knob. Turn it out until it is not touching the plate then screw it back in 3 turns. Do not twist the grip when trying to start, if it starts adjust the knob for the best idle then do a carb synch, information and vids here: http://intruders-alert.com/viewtopic.php?f=32&t=4139


[emoji41]
Grow old disgracefully young man.

Kdp89
Tricycles are Cool
Posts: 16
Joined: Sun May 14, 2017 6:57 pm
My Bike: 1986 vs750

Re: 1986 vs750 intruder rebuild

Post by Kdp89 »

Well, I tried the above advice and got nothing. So in a last ditch before calling the mechanic I went out and bought a compression tester (which admittedly should have been one of the first things I did). The results aren't good. The front cylinder is at about 25 psi and the rear is getting maybe 5 psi. Now to decide whether I want to pull the motor or call this a lost cause and sell it as a parts bike.

Lechy
Joined a 1000cc Club
Posts: 3955
Joined: Tue Dec 09, 2014 9:58 pm
My Bike: VS800 Honda Phantom 200

Re: 1986 vs750 intruder rebuild

Post by Lechy »

How did you do the compression test? If you didn't have wide open throttle whilst cranking you will get this kind of result. Have you checked the valve lash? You may find that some of the valves are stuck in a partially open position due to it having been stood idle for a long time.
Here is a write up:
Background:

If valve clearances are too tight, the valves can be seriously damaged by warping or burning and compression will eventually suffer from lack of proper valve seating. Valves are cooled by resting against the valve seat if they're open too long, they have insufficient time to rest against their seats and transfer their heat to the cylinder head. On the other hand, if the clearance is too loose, the result will be rough running, loss of power, and excessive wear of the valve train components. Therefore, if you must choose, remember that a little looser is better than tighter.

Before you adjust the valves the engine must be dead cold. In other words, the engine must have been left to cool overnight. The cold clearance is .003 .005 of an inch on all valves. I ended up setting them at .004 all around. However, if you have a bike that tends to overheat, you can set the exhaust to .005 You can also do the opposite, set your intake valves to .005 for better breathing.

Procedure:

If you have a stand or lift, raise the bike; if not, place a 2X4 block of wood under the side stand to prop it up, but make absolutely sure it is firm to avoid having it fall down.

Remove seats and gas tank.

Remove the front cylinder right hand chrome head cover and take the spark plug out (or just loosen). Remove the rear cylinder left hand chrome head cover and also take the spark plug out (this makes it easier to turn the engine over by hand ). You will be working on the front cylinder valves from the right side of the bike and working on the rear cylinder valves from the left side of the bike.

On the top front and top rear of each cylinder head are the valve covers (four in total). Remove them ([six] 8 mm & [two]10 mm nuts). Make sure you note exactly where and how each cover is placed since they have a thick and thin side. It's a cumbersome process and you will have to loosen the wiring straps (and other stuff) and move around the wiring harness (and other stuff) that runs along the top of the frame to get better access. If your fingers are not so nimble you might have to take out the front carb. The valve covers have rubber O-rings which must be cleaned before reinstall (if the O-rings are flattened or in bad condition, buy new ones). Also, clean the valve covers well and make sure you place the O-ring back in correctly, since it fits in a certain manner. Coat the O-rings with a little oil before reinstall.

On the left engine case cover is a large slotted plug, remove; be very careful since the plug is chrome and sometimes very tight, therefore you can mess it up real easy. This plug has a rubber O-ring which you must cleaned (replace if damaged); smear a little oil before reinstalling. Under that plug is a nut (17 mm) you use to turn the engine crankshaft counter-clockwise. Just in front of this large plug is a smaller plug on the front side of the left engine cover. Remove the smaller plug with an Allen wrench. This is the sight glass used to align your valve timing marks. There is an alignment arrow (a triangle) stamped on the case on the left side of the sight glass looking at it from the front.

Turn the crankshaft counter-clockwise (if you look carefully, the direction arrow is stamped on the flywheel) {also, I turn the engine over a couple of times to take up any slack} until you see on the flywheel (very close to each other) one F/F and one F/T mark (meaning that the front cylinder piston is at top dead center and its exhaust and intake valves are either fully closed or open ). If you keep turning you will reach the R/F and R/T marks (meaning that the rear cylinder piston is at top dead center and its exhaust and intake valves are either fully closed or open). If for some reason you go past the marks, do not turn back, just keep on turning counter-clockwise until you reach them again. Remember that you might have to go several turns because what you are trying to achieve is place the piston at TDC with the valves in the fully closed position, ie: "relaxed". The F/F and R/F marks are for ignition timing (yes, although the ignition is digital, it is timed at the factory). The F/T and R/T marks are for adjusting the valves. Adjust valves at these marks. You will work on the front cylinder first, so get to the F/T mark first. Once the F/T mark is in the center of the sight glass and aligned with the alignment arrow, you must check to see if there is free play at both the intake (on the rear part of the cylinder) and exhaust (on the front part of the cylinder) valve rocker arms by jiggling them up and down. The movement is slight. If not, rotate the crankshaft 360 degrees (counter-clockwise) and check again until the valves reach what I call the "relaxed" position.

Loosen the valve adjuster lock nut (10 mm). It is tight, so be careful not to scrape your knuckles. After the lock nut is loose, hold it with a wrench and work the adjusting bolt back and forth to get the threads in a little easier adjusting shape. You need a special adjuster wrench since the top of the adjuster nut is square. I used needle nose pliers because that's all I had at the time, but buy the wrench.

Insert a feeler gauge between the exhaust valve rocker arm adjuster bolt and the end of the valve. The fit is really tight and you've got to struggle, bend and move the feeler to get it right. Turn the adjuster until you feel a slight drag on the feeler gauge when it is inserted and withdrawn. Close your eyes and feel the slide of the feeler blade to become acquainted with the sensation. If you have a friend who knows how to work a feeler gauge ask him to check it. You should hear and feel a particular rubbing sound as the feeler slides between the metal surfaces. Once you've got it, press the opposite end of the rocker (opposite to where the feeler is) to make sure it's down and you are not getting a false reading (you can also lift the rocker for the same effect). If everything is OK, carefully place a wrench on the adjuster lock nut and on top of that wrench place the special adjuster bolt wrench and tighten the lock nut while holding the adjuster bolt to keep it from moving. Tighten partially, recheck the clearance and if it's right, tighten the lock nut all the way. Recheck clearance. Repeat for the remaining exhaust valve and do the same for the intake valves. (800's have four valves per cylinder).

Now turn the crankshaft counter-clockwise until you reach the R/T mark and repeat the above for the rear cylinder. Make sure you do not go past the mark as the turn will be about 285 degrees. Make sure the valves are in the "relaxed" position.

The biggest hassle when adjusting is being able to slide that straight feeler gauge into a most restricted space, but curving the blade and a few McGyver style moves should do it. If you have never adjusted valves get ready to spend a good while, some cussin' and adjusting several times 'till you get it down pat. Once you have some practice it's faster and easier.

Install the valve, timing and crankshaft covers. Organize your wiring, straps and "other stuff"; Remember to tighten the spark plugs! Replace the cylinder head chrome covers, tank and seats.
Finally, because you moved the throttle cables around a carb synch will be a good idea.
Grow old disgracefully young man.

ladislio
Tricycles are Cool
Posts: 1
Joined: Mon Aug 14, 2017 3:46 pm
My Bike: 1987 suzuki intruder vs700

Re: 1986 vs750 intruder rebuild

Post by ladislio »

I have the same motorcycle and I am having trouble putonghua the swing arm on and installing the drive shaft? I just got the bike and it came with the swing arm rear wheel and drive shaft all off. And I am having a problem outing it back together. Because I know what to do but don't know what order to do it in. Any help would be greatly appreciated. Thank you.

Post Reply