Help?? Won't Stay Running After New Gaskets!

[Anonymous]

Ok, here's the story. I have an 82 GS650G with 13,595 miles on it that was pouring oil out of the sump and head. It sat in a garage for about ten years (long before I got a hold if it) and the gaskets dried out on it, so far as I can tell. I bought a Vesrah gasket set, pulled the engine, put in all new gaskets, gave it a cleaning and slapped it back in. It started up with full choke, but was only idling at about 1200 RPM and it was running really rough, sounded like bad misfiring. I checked all the plugs after this, they were black, covered in powder, not oil. I checked them against the valve cover and they all sparked. Compression across all 4 cylinders is 152, same as it was before the tear down. At this point the bike will start on full choke but runs really rough and at a low idle. I can move the choke off if I throttle it, but if I let go it dies. Here are some questions, any help is appreciated.

First off, what is a starting point for the air/fuel screws? Mine had plugs in them, I drilled out the plugs and got the screws unfrozen (barely, they're still really tight to turn) but I don't know what a good starting point is.

Next, the bike always ran rich. After high way riding (75mph) or about 600 miles, the plugs would be fouled with carbon powder (not oil). I used to just carry an extra set of plugs and change 'em when needed, but this seems almost like a fuel starvation issue. Any thoughts?

Finally, I cleaned and synched the carbs last year right before I stored it for the winter (no signs of corrosion in tank or bowls), and I rode the bike from April through three days ago, so I don't think this is an issue. I think I covered most of it, please hit me with some advice!!!

 

[moto_dan]

Re: Help?? Won't Stay Running After New Gaskets!

First off, what is a starting point for the air/fuel screws? Mine had plugs in them, I drilled out the plugs and got the screws unfrozen (barely, they're still really tight to turn) but I don't know what a good starting point is.

Next, the bike always ran rich. After high way riding (75mph) or about 600 miles, the plugs would be fouled with carbon powder (not oil). I used to just carry an extra set of plugs and change 'em when needed, but this seems almost like a fuel starvation issue. Any thoughts?

A few random comments.
1.5 - 3 turns from gentle seating will get you in the ball park. Have you had your carbs totally apart and cleaned per the Carb cleaning pages? Improper float level can cause a rich or lean condition. What condition is your air cleaner? Plug type(NGK?) and heat range? Do the plugs all look the same or is #2 different? Fuel starvation would produce a lean condition rather than the rich condition you described.

 

[Anonymous]

Carbs cleaned

Carbs cleaned

Hey Dan,

I cleaned them at the end of last season and only rode it lightly for a few months this year, oil leak was too bad. The air cleaner was also new last season, it's still in good shape. It's an UNI cone filter. The plugs are NGK D8EA, I don't know what the heat range is, but they're the plugs that the Clymer manual calls for.

So, just so I get this straight, running the air/fuel screws in (clockwise) will lean out the mixture, backing them out (counterclockwise) will make it richer? So, as you've said, run them in and back them out about 2 turns and go from there?

#3 plug has always seemed the blackest when I've pulled them. In the past, it has always been running rich. Now though, the bike barely starts, and only with full choke, so I'm wondering if it's a fuel starvation issue now, or I guess it could be flooding???

 

[Anonymous]

Check those rubber intake manifolds (see the post about "help me idle").

Check the fuel petcock vacuum hose. This should go to the #2 carb.

The starting point for the air/fuel mixture screws for my 81 GS750E is 1 1/4 turns open. Probably close for yours. I noticed the plugs on two of mine were drilled, but not fully pulled out of the threads. When I cleaned the threads, the screws turned a lot easier. If they are stuck though, I'd suspect that they may be good and gummed up down below aroung the spring and o-rings there to.

Lift the sliders and let them fall. If they hang up at all, pull them and polish the needles. These must move smoothly.

Check the float levels, make sure they are correct and that the floats actually do float. I pulled mine and let them all float together overnight to see if they all were still at the same level in the morning.

Check the o-rings around the float needle and seat to make sure the floats can actually do their job. Maybe time to rebuild in the old dunk tank.

Clean all the connectors in the ignition circuit. I found my ignitor wires had loosened up a lot, making for very poor ignition strength.

Put a fuel filter in (for sure).

Cheers,

Roger Moore (been there, done that).

 

[moto_dan]

NGK's are good and the heat range #8 is correct for normal riding conditions. Could your choke(enrichening) mechanism be stuck? Is your Uni filter the kind that needs to be oiled? If oiled too much this could cause the rich condition but would not explain the necessity to use the choke. Roger has several other ideas. Stay tuned.

 

[Anonymous]

Still No Go

Still No Go

All right, I pulled the carbs and opened up, they were all clean & floats adjusted properly. I can only move my 1 & 2 air screws, three and four are totally frozen and starting to strip. Can I drill out the actual air needles and buy new ones? Checked the vacuum line & gas line, they're fine. As far as I know, the intake boots are ok, but I can't even get it running long enough to check at this point. After putting the carbs back in, the bike won't start at all. With the choke full on, it kicks over for about 2 seconds then just dies again. Help!

 

[moto_dan]

Re: Still No Go....Response kind of long!

Re: Still No Go....Response kind of long!

All right, I pulled the carbs and opened up, they were all clean & floats adjusted properly. I can only move my 1 & 2 air screws, three and four are totally frozen and starting to strip. Can I drill out the actual air needles and buy new ones? Checked the vacuum line & gas line, they're fine. As far as I know, the intake boots are ok, but I can't even get it running long enough to check at this point. After putting the carbs back in, the bike won't start at all. With the choke full on, it kicks over for about 2 seconds then just dies again. Help!

Drilling out the stuck screws would be risky. Try soaking the screws in WD40 or other solvent a day or two and see if they loosen up. If these screws are stuck this tight then I would suspect the internal components of the carbs need a thorough cleaning, even though you cleaned and synced them last year. If it were my bike here's what I would do to eliminate the fuel side of the equation of a non/poorly running engine.

1. Check the fuel petcock for proper operation.
2. Insure the lines are connected properly. Vacuum from #2 intake to petcock, Largest line(fuel line)from between #2 and #3 to large nipple on petcock. The two smaller lines are vent tubes connect between carbs 1-3 and 2-4 are run above the air cleaner.
3. Go one more time through my carbs using the Carb cleaning series as my guide. Paying close attention to condition of o-rings, and other internal parts. Some solvents are harmful to o-rings and if you used the wrong cleaner last year possibly it harmed the o-rings.
Sorry I haven't been any help, maybe others will come to your rescue, but don't give up on it.

 

[Anonymous]

Timing Was Off

Timing Was Off

Hey,

Thanks for your replies, I just took it back apart and rechecked my timing, the cam was off by 1 tooth. Damn. It got late and dark by the time I was done, so I only gave it few tries. Still didn't start, but hopefully this weekend I can work something out. What are the reprecussions of running the engine briefly with the timing off? Hopefully nothing too bad :?