82 gs400tz wont rev or run without choke

[ta2ooz]

first time post here guys
i have an 82 gs400tz it was parked for 16 years in a shed,has 30000kms on it(canadian eh!)here is the trouble,they previous owner had tried a carb rebuild,and then it sat for another 8 yrs.after he did the carbs it was running the same as it is now,i have gone through the carbs about 6 times now and can not find the elusive problem so here it is. full choke it fires up,if you even touch the throttle it bogs a little and tries to die,if you try to take the choke off it dies. If you time a shot of carb cleaner down the throat of either carb i can get it to rev.so i think it is definatly fuel related or air related(as opposed to electrical). Here is the question__ if the plunger diaphragms are good and do not leak,and there is fresh fuel in the tank,and the petcock has been bypassed,the main air bleeds have been re and re'd and cleaned thouroghly(i think) what the heck is going on,why can i get no fuel into the engine,float height is at .85 in.
here is hoping someone has run into this and found a fix.
thanks for your time guys and gals

 

[Dave8338]

My guess is that the carbs are still dirty. Also...do you have an air filter in the bike? Stock exhaust? These bikes are VERY lean from the factory setting and IF there is any additional air getting to the engine that is not being pulled through the filter, then you WILL have problems. Are all clamps tight? Carb boots soft? Battery FULLY charged (this does make a difference) and everything up to speed with the electricals?

Welcome to the fourm...

 

[ta2ooz]

i mangled the air box getting it out,all rubber appears to be in good condition,i have a couple of pod filter for it but it was running this way with the stock airbox and no filter.any ideas on where the hidden port is?

 

[Dave8338]

i mangled the air box getting it out,all rubber appears to be in good condition,i have a couple of pod filter for it but it was running this way with the stock airbox and no filter.any ideas on where the hidden port is?

These bikes need a filter. If you put the pods on, you'll be looking at a rejet to get it to run right. I would reinstall the stock air box (mangled parts either fixed or taped over) with the STOCK filter and retest. You won't get it to run right without a filter. I know when I was working on mine..just the smallest amount of air restriction (through the filter) made a huge change in overall performance.

 

[ta2ooz]

Thanks alot for your time,I think for testing purposes i will try and tape up the pods and see if i can restrict it that way,maybe hog out the jets as well for now.

 

[ta2ooz]

got home and re assy'd carbs,got a pin vise and drilled out the mains a bit larger,revvs up but pukes fuel out the air bleeds,am ordering some jets tomorrow. thnx again,was starting to pull my hair out

 

[BassCliff]

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[AOD]

Usually if only runs on the choke, the pilot jets are clogged.

 

[ta2ooz]

down to a last couple of hairs

down to a last couple of hairs

ok here is the new turn of events,i put a set of 118's in,because i had them first,no change,got some more jets today,put in 2 127.5's,still no change,thought i needed differnt pods,put on a set of actual k&n ones,still no change,there is no fuel coming out of the air bleeds now but,while idling with the choke on full the engine will rev up to what sounds like 3500 rpm after it warms up a bit,just slightly crack the throttle and it boggs out and dies. like i said before with the carb clean timed with a throttle crack it will rev up,also when it is reving 3500 and i choke the engine out by palming the carb inlet to almost stall,it will briefly rev up and have throttle response,, just to qualify myself i have been an automotive tech for about 18 years,had lots of experience back in the day with carbs etc,this is a real head scratcher for me,,also shimmed the needles up 2 washers. anyone got any ideas??

 

[fallous]

Did you actually disassemble the carbs and put them in carb dip for a day or two? Trust me, these things will NOT clean up by just blowing spray can carb cleaner on them.

 

[Big T]

Putting larger main jets in it is futile.

It doesn't start or idle on the mains

You need clean pilot jets and clean carbs

A bike that has sat for over 8 years needs a complete disassembly and dip, new O rings, new intake boots and proper air flow.

You'll get no results with what you are doing.

 

[ta2ooz]

i am starting to realize i came to the right place,carbs will be dipped tomorrow,thanks guys

 

[ta2ooz]

ok gottem dipped and the turned out pretty good,have not put them back on yet but here is a thought i had, I think in my ignorance of motorcycle carbs accidentally may have plugged off the vent hose????.do ya guys think this could hav a bearing of my issues.oops

 

[donimo]

not sure if there IS a vent hose, mine doesnt have one.

one fuel hose, one vacuum hose to activate the petcock, and yes that would make a huge difference. if it was pinched off it might have pulled enough vacuum to idle a bit with choke (high vaccum) but normal idle would have died, revving might have died too, could be your issue right there?

 

[ta2ooz]

well we live and we learn

well we live and we learn

IT RUNS
and i will bet dollars to doghnuts that it was that stupid vent tube,makes perfect sense now.hindsight and all.thanks to everyone for all the help,i just took her for its maiden voyage 5 min romp through the back streets
went pretty good,better than expected for a 400,pleasantly suprised
thanks again all,will be talkin to yall soon:clap:

 

[briyenkieth]

IT RUNS
and i will bet dollars to doghnuts that it was that stupid vent tube,makes perfect sense now.hindsight and all.thanks to everyone for all the help,i just took her for its maiden voyage 5 min romp through the back streets
went pretty good,better than expected for a 400,pleasantly suprised
thanks again all,will be talkin to yall soon:clap:

Nice! Congrats and yes the 400 is a surprising ride. The more I tune mine the smoother and more powerful it becomes. Good enuf to keep up with traffic on the freeways here in los angeles. That floored me doing 70+ and passing folks.