BigT

Try swapping the spark plug leads for each coil. Take 1 and swap it with 4. Swap 2 and 3. Does the problem now move so 1 and 2 aren't firing? Start it up in the dark and see if the spark plug caps are shorting out while its running Does your bike still have points?

All good advice so far,, but I have two suggestions on the carb boots: 1. There's no substitute for new, pliable boots. You will find this is the best money (other than new tires) you will spend on the bike. 2. Rather than heating, which is temporary and you're left with hard boots, I refurbish the rubber. There are several products on the market for this, but I bought a bottle of commercial wintergreen oil off the net for about $20. Mix it 1 part wintergreen oil/ 5 parts solvent. I use Xylene as recommended by others. Get a glass jar,measure in some product, drop in a boot and check it hourly until it is soft. you can then use it for all of the other rubber bits on the bike, except the carb O rings. Get those new from cycleorings.com* or a more local source. If you leave the part in the mix too long, it will expand. Just take it out and leave it on end for a day or so. It will off gas back to its original form. What we refer to as "rubber" on the bike is actually several different materials. Always check a part in the mix regularly to judge when it is soft. Some materials will actually melt if left in overnight or longer. Ask me how I know *If naming a supplier is not allowed, please let me know. The owner (not me) is a GS guy and has many satisfied customers around the world

The US got the G and the GL, which is what yours is. the yokes of the GL are different than standard. So, what JohnR said is correct on replacement units. Those units will function better, but will look about the same. Not sure what you mean by clean look.

If it fires right up and sounds good, I wouldn't worry too much Easy check - 4 soda straws, pull spark plugs and insert straws. Turn motor with a wrench to the TDC 1-4 mark. Mark straws 1-4 with a felt pen. Rotate motor back and forth a bit to confirm TDC. Repeat with 2-3

Johnr, I've never seen a standard G model with leading axle forks. I've got 2 850s and neither have them. GL models have a leading axle fork Micktodd, if you looking for an older front end, the best is an 84 GK (touring bike) which has 41 mm tubes. Straight swap Most newer forks will fit with minor modifications, 90s Katanas have the closest swap, the stem is the same. Bandit front ends need a stem swap

That should do the trick. If you leave them in too long, they swell up. They'll return to form in a few days

Supposedly, they do interchange. Or, soak the originals in mint oil

I've been contemplating your situation and I have a few insights: 1. The cracked pick up tubes are odd. Ed or one of the guys on the GSR wrote a tutorial on replacing them a while back. Sorry, no link 2. The choke system should not be supplying any extra fuel into the carb once the choke plungers are pushed back down. The plungers block the holes so no fuel can come through. Therefore, perhaps your issue is that the #1 and #4 choke lifter arms are installed upside down? They are asymmetrical and would therefore not close off the hole in the choke system and extra fuel would be coming in, causing the plugs to foul? 3. If moving the air screw doesn't create any changes, there's probably an air leak on top of the other issues. How are the head to boot O rings and the carb boots themselves? Also, did you check the pilot fuel screw holes to see if they are reamed wide from someone tightening the screws too tight/snapping off the tip? Are the fuel screws set around 7/8 turn out? 4. I didn't see your build specs, but if you used the later big port head, what carb boots are you using? CV carbs or VM carbs

Marzocchi is out of business. They made the Strada and the Symbol back in the 1980's Rebuild kits are still available

The motors will be the same, carbs may differ The Feds are pretty strict about the speedo lay out, or are you referring to the 80 mph speedo? 80 mph speedo was Feds attempt to slow down superbikes

I was here before, back in the day on that other site

a better pic of mt 78

The 78 I bought brand new , the blue one, with my mate Rob and his 78 at one of the best riding spots anywhere wish I could post my GPz or my Mark III D Ducati

Here's my ex racer coming home, It's changed a bit since then