Tuning and Jetting '80 GS1100L 16v

[Guest]

I've been going at this for a few weeks now and I am turning to you all for help. Initially, my bike would run well, but was slightly lean. This was with the stock airbox and a supertrapp exhaust. I decided I would upgrade to pod filters and buy a dynojet kit. After doing so, my bike is running like trash.

I am using 138 mains, new needles on the 3rd clip from the top. The WOT section of the power band seems to be okay. At idle however, when I blip the throttle, the carbs pop and backfire. This tells me that the idle circuit is lean, but would I need to change the pilot jet if it wasn't included in the kit? It feels like I wasted $120 on a piece of **** kit that didn't even include everything I needed.

Also, I can't start from a standstill, the engine can't produce enough torque to move without stalling.

Please advise.

[posplayr]

I've been going at this for a few weeks now and I am turning to you all for help. Initially, my bike would run well, but was slightly lean. This was with the stock airbox and a supertrapp exhaust. I decided I would upgrade to pod filters and buy a dynojet kit. After doing so, my bike is running like trash.

I am using 138 mains, new needles on the 3rd clip from the top. The WOT section of the power band seems to be okay. At idle however, when I blip the throttle, the carbs pop and backfire. This tells me that the idle circuit is lean, but would I need to change the pilot jet if it wasn't included in the kit? It feels like I wasted $120 on a piece of **** kit that didn't even include everything I needed.

Also, I can't start from a standstill, the engine can't produce enough torque to move without stalling.

Please advise.

You did good, but you might have something else going on.

The only thing that sounds like you are missing is the 47.5 pilots which don't come with the dyno jet kit. It does sound worse than it should be; how do your plugs look? Also did you dip and clean out all the passages in the carbs. Maybe Chef1366 has some other recommendations.

[yoshisakan]

Yeah, I broke down the carbs and soaked them in pinesol. They are free of corrosion and deposits now. Before doing so, i was leaking fuel from the intake. I figured out it was the needle valve o-rings covered in corrosion. So I fixed that and replaced the fuel petcock.

I'm still not sure my float height is correct. I've changed them a few times with the same results. I'm going to readjust them to 20mm above gasket level.

I pulled the plug on cylinder one, it was brown.

Also, do you know the thread size of the pilot air adjustment screws? I need to do some repair work to one of those.

[yoshisakan]

You did good, but you might have something else going on.

The only thing that sounds like you are missing is the 47.5 pilots which don't come with the dyno jet kit. It does sound worse than it should be; how do your plugs look? Also did you dip and clean out all the passages in the carbs. Maybe Chef1366 has some other recommendations.

Thanks for the advice. I just switched out the 40 pilots with some 45s that I found in the garage. It is running beautifully now. I am using the 160 idle air jets too. The bike pulled so hard that the clutch was slipping. I should probably change the oil, since theres probably fuel in it now. I just changed the clutch springs last year. I also adjusted my float height back to 22mm

[posplayr]

Thanks for the advice. I just switched out the 40 pilots with some 45s that I found in the garage. It is running beautifully now. I am using the 160 idle air jets too. The bike pulled so hard that the clutch was slipping. I should probably change the oil, since theres probably fuel in it now. I just changed the clutch springs last year. I also adjusted my float height back to 22mm

good news, you should order those 47.5's and get some barnet HD springs. 6 in a pack and you can start by alternating 3 HD BArnett and 3 stock. As mods continue and HP climbs you will need all 6.

Also Get a HD clutch nut (you can search for references to it) while you are in there else it will start knocking and giving more worries. You can also check and see how bad your clutch is, might need some shimming or go all out and find a HD gorilla hub. Used to be able to find them for about $100-$125 but prices have likely gone up now.

Remember that bike is going to be fast but has definite limitation in the cornering department.

[chef1366]

I have the three Barnett clutch springs if you decide to go that route.
These carbs came stock with the 45 pilots and 160 pilot air jet. I would go up to the 47.5 if you have popping on decal.
With the 45 pilots you will have the idle mixture screws out at least 3.5-4 turns out just for a nice idle.

[yoshisakan]

I read in a thread that they came with 40s. Mine were rebuilt by the previous owner so who knows why he was runnin them with an exhaust. I'll ordered some 47.5s because it is popping under deceleration.

As far as the handing, this is gonna be for another thread, but would swapping a more modern gsxr fork and swing arm help a lot in this area? My bike is really wobbly in the turns, so something my just be loose.