So I bought a second one..

[Guest]

Aaaah... replied in the other thread... pop the fuel cap next time it happens. If the breather vent is blocked it will starve your carbs of fuel...

 

[jfman]

Thanks for the advice.

Here`s the kicker... The fuel cap wont come off. The lock is messed up, the key turns but I cant remove the cap.

After draining it, I had to lay the tank upside down and fill it thru the petcock hole.

 

[Guest]

Thanks for the advice.

Here`s the kicker... The fuel cap wont come off. The lock is messed up, the key turns but I cant remove the cap.

After draining it, I had to lay the tank upside down and fill it thru the petcock hole.

In that case I reckon there's a good chance you found the source of your problem

 

[jfman]

removing the fuel cap had no effect...

I pulled the carbs and the pilot jets were clogged. The bike ran on choke because the choke enriches the mictures but whit the choke off the bike was getting no fuel at all unless I gave it throttle.


Update: after it was all cleaned and I had purchased my new pilot jet plugs (old ones were dry-rotten) I pout the carbs back in and they bike doesnt seem to run much better.

So I started comparing parts between the 1983 and the 1980. The 1980 runs like a freakin dream so I figured it was worth a shot.

The 1980 carbs dont seem to be as clean from the outside but then I look at the intake boots. They look like they are new while on the 1983 they are ver dryrot looking.(thank you PO of the 1980) So I crank the bike up and I spray a little bit of startiong fuel around the boots = bike start revving very very high like 5k.

This means = new intake boots are needed.

Went to an online vendor to buy the boots and seals - ended up buying 175$ worth of stuff... ouch!

 

[brad020]

On my 1980 I just pull the choke knob and it stays on choke until I push it back in..

On my bike, the enrichener rail has a spring-loaded ball in each carb that provides enough friction to hold the knob wherever you set it. Except that both of these tiny steel balls fell out of my twin and now I have the problem of needing to hold the knob to keep it enriched.

 

[jfman]

New boots and seals today...


I can tell a big difference between the old boots and the news ones. Old ones were like plastic they were so hard.


But sadly the bike doesnt run any better. The right side seems to be the good side.

When I crank it up, the right pipe becomes warm right away while the left side stays cool. After 2-3 minutes I can still grab the left head pipe with my bare hands. Fuel does get to the left carb because if I lift the slide I can feel the fuel come right away from the the main jet. It's a pilot jet / idle screw issue...

Carbs are coming off for the second time...

 

[jfman]

Carbs are off once again.

This time it has to be the good one because I got complaints about the noise from the bike idling as I was fiddling with the bike.

The neighbors are ****ed, I live in a city and I tinker with the bike at my apt complex.


They were not confrontational about it but yeah I have to cool things down.

 

[jfman]

She finaly runs decent! Both cylinders warm up well and seem even. It doesnt bog down anymore as well.

I rode her around for on 15 minutes but she seems fine except for maybe a slight hang and hunt in the idle.

Gonna tag her and go for a longer ride this week to see how it all settles.

She defenetly feels stronger than my 1980 gs400.

 

[Guest]

Nice one! Glad to hear she's gettin' there

Bugger on the neighbours but what can you do hey?

 

[jfman]

Man down man down! I started riding it to work this week. Got 100 miles on her so far and it ran well.

Today I was coming home from work on it. When I first started it the throttle response was boggy so I reved it high and it cleared up and was running fine.

After 2-3 minutes on the road it started bogging down quite a bit. I had to stay on the throttle at lights to make sure it would run. I could hear some "droning"(you know the sound a V8 car with loud exhaust makes when you decelerate) in the right exhaust. Also the right exhaust was not as warm as the left.

I sat at a red light for 3 minutes keeping the revs high then when I took off it was boggy and when it started accelerating correctly at full throttle there was a huge dark cloud of smoke behind me. Think nasty black smoke like a diesel.

After that I had open roads ahead and I was running the bike in the high revs and it and it slowly started bogging down more and more and more until it quit running. It wont start back up.

I think some crap got into the carb again.

I am not happy...

Parked it on a side street and hitched a ride home.

 

[Guest]

Float needle probably has some crap in it. I've seen and felt the same thing on mine when the needles stuck open. It works great up top but dies when you wind down.

Was it leaking at all when you stopped ?


You can take the bowls off and the floats and needles and seats... while its on the bike on the side of the road in pitch black with only the light coming from your blinkers to see what your doing with cars wizing by. Changing the screws to alen bolts does help.

 

[jfman]

Float needle probably has some crap in it. I've seen and felt the same thing on mine when the needles stuck open. It works great up top but dies when you wind down.

Was it leaking at all when you stopped ?


You can take the bowls off and the floats and needles and seats... while its on the bike on the side of the road in pitch black with only the light coming from your blinkers to see what your doing with cars wizing by. Changing the screws to alen bolts does help.

Not leaking and no smell of gas afaik. I think I'm going to buy new needles because I did not replace them before. They do have a ridge in the rubber part of them.

But I think the problem could come from crap that was in the tank making its way into the carbs again.

 

[Guest]

Not leaking and no smell of gas afaik. I think I'm going to buy new needles because I did not replace them before. They do have a ridge in the rubber part of them.

But I think the problem could come from crap that was in the tank making its way into the carbs again.

I sandblasted my tank and got allot of grit coming through the petcock filter.

Instead of installing another filter I used a long piece of tubing from the petcock around the back carb boot and then to the middle of the carbs.

That let all the grit and sediment settle in the loop on the bottom instead of making it to the carbs and didn't restrict flow.

Might help to try something similar until you get the crap out.


I wonder what finally caused it to stop, when will you get back to it ?

 

[jfman]

It quit as I was riding it. It died on the throttle... very odd. I was still going like 20mph so I used compression to get her started again. It caught back up only to bog again to a complete stop.

To be honest I am not sure if the issue is flooding or starving..... I really dont know. I'll have to inspect the plugs when I get to it...



The fuel line loop is a good idea, I'll have to try that.


If it's flooded on the right side I will have to think about the petcock vaccum line as well.

 

[jfman]

I checked on this bike the other day and the fuell has leaked into the bottom end...

New petock has been bought(40$ ebay) and will have to drain the oil, pull the plugs before i can ride it again.

 

[Guest]

Sounds like you found the problem

These bikes definitely do bog out when they flood even at WOT.