[paraord]

Hey Guys,

Long time lurker first time poster. I have an 87 TW200 i got from a buddy who left it to rot under a tarp in his garage. I got it running by cleaning the carb up and the tank. It ran great for me as I bombed around the snow and mud.

Now the other week I finally went thru the DMV hoops to get a lost/no titled bike, retitled and registered(In NYS those are some fun hoops to jump thru).

When on the road at higher speeds ( and by higher i mean like 30) and higher RPMS its like someone is hittin the kill switch super fast so its going baaa ba ba ba ba ba. Thats about as best as I can describe it.

This doesnt happen when Im goofin around the woods or anything because I rarely go over 20mph, just when Im on the road and trying to go 40mph or more. I have cleaned the carb, main jet, pilot jet, checked the needle its nice clean and shiny. I checked the fuel diaphragm and its in great shape. The tank is good, little to no junk in there. Im pretty handy with a wrench and i know my way around cleaning a carb.



So, what do you guys think it is? Maybe needing a rejet to a 118 or 120? By the way tonight i spent the last 2 hours fiddling with the mixture screw. 2 turns out im getting the least amount of this surging or whatever you want to call it. Its still alot and 50mph is the top end of what it will do. Im running a stock front sprocket and I think a 50tooth in the rear.

Thanks in advance everyone!

-Andrew

 

[ezman671]

Mine was also brought back from years of storage. Got it running by cleaning like you did but it still missed at higher speed.



Put lotza Seafoam in with the gas ( as in 2 or 3 times what they say to do ) and run it easy for a few miles then run it hard so it skips and misses for a mile or so.



I did that and all of a sudden while going up a slope at WOT it stopped missing and has not missed a beat since.



Good luck.

 

[Rainman]

I'd check all of your electrical connections. My 1990 did the same thing, but mine would skip and miss on washboard roads or when I hit a sudden bump. Make sure you unplug each connector and look underneath. Everything looked fine on mine until I physically unplugged each connector. I found a couple that were bad, so I cut them off and put on new weather proof connectors. All is fine now.

 

[qwerty]

Since tweeking the pilot screw makes a difference I'd suspect a fuel flow issue. Maybe clean the petcock, check the little screen above the float needle seat, check float height. In fact, when I resurrect a bike after a long period of not being used, first thing I do is a complete fuel system disassembly, clean, and reassembly. Saves a lot of aggravation fixing things that aren't causing problems.

 

[paraord]

Thanks for the replies everyone!

EZman-Im going to pick up a can of seafoam tonight and run that thru

rainman-all connections are checked and tight/no corrosion and no worn thru wires

qwerty-it is fuel delivery as i figured too but its in the carb



so last night i was looking at my spare carb that i have just letting my wheels turn. and i happened to notice a HUGE difference in jet sizes between the two. were talking it looks like jet that was on the bike was half as big as the spare carb (side note the spare carb became the working carb because someone decided to use kreem to line the gas tank. long story short the kreem decided it wanted to go where the gas went and literally plugged the carb up to no return and i washed the inside of the tank with acetone and ball bearings for what seemed forever). So someone did a little jet job and had no idea what they were doing, or knew they were not going to get over 20mph!



I switched the two jets and voila! it made it to 50-55! And there were far less of these misses. I didnt have time to tweak it with the air/mix screw last night but as it sits it is 2 and 1/4 out.



So now my question is Which way should i go to further lessen these surge things?

 

[qwerty]

Main jet first. What size jet are you running now? Needle height second. Pilot jet third.



If there is still a surge, raise the needle a bit and see if that helps. Simply remove the needle, go to a hardware store or hobby shop, and buy a washer that will fit over the needle but not the circlip. With the washer between the slide and circlip, the needle will sit higher in the main nozzle at mid throttle and allow a richer mixture.



Leave the pilot at 2 1/4 turns until the high and mid throttle jetting is sorted.