Rebuilding my 1980 GS250T here...

[Guest]

Much better than the torn up one that was on there!

What did you find with the jets? Or have you not gotten that far yet?

 

[isu2014]

The jets are the stock size that the manual states. I adjusted the floats a bit and am going to reclean everything. Hopefully it fixes the problem because it's pretty loud right now and the baffles sounded nice.

 

[Guest]

Good stuff, worth while checking the colour of the plugs too to work out if it's rich or lean.

 

[isu2014]

It was rich so that's why I thought it was rejetted. Now I'm baffled. I messed with the mixture screws and it always ran good without baffles but as soon as I put the baffles in it just runs like crap.

 

[Guest]

Now I'm baffled.

If you have stock jets, no baffles, and it runs well... that tells me something isn't right with the fuel and/or air intake circuit.

If you put baffles in with the stock setup and it runs rich and not right, that makes me think that even more.

I can't recall intake wise now but is the stock airbox on it etc.?

All I can suggest right now is to start working out if there's a restriction in the intake somewhere that is not letting enough air in, and to check the needle heights, float height, etc. and make sure it all should be ok.

 

[isu2014]

The stock airbox is on, but I think the PO put an aftermarket air filter in it. I'll have to mess with that when I'm tuning it too, just to experiment if that's an issue.

Right now I'm just going to go straight by the manual and see what happens after everything is done to Haynes spec.

 

[Guest]

Cool, sounds like a good plan to me!

 

[isu2014]

I checked the main air jet and it is one size smaller than factory. That would be part of my rich issue. Going to go back to factory with them for sure.

 

[Guest]

Aaah ok, that won't help!

 

[isu2014]

I finally think I figured out the issue of the running issues. My pilot jets were still a little dirty. Cleaned them and adjusted the float height. When I was putting on the carbs, I noticed the airbox rubber outlets weren't sealing around the carbs. They were hard as a rock. Ordered new ones. This should help maintain a proper air/fuel mixture and make it easier to tune.

 

[Guest]

Good find, those rubber boots make a world of difference if they don't seal properly!

 

[isu2014]

I finally got the bike running great now!
I put new outlets on the airbox, new air filter, and adjusted the carb float height and synched them. Pushed it outside and it fired right up and idled nicely WITH the baffles in the mufflers. It pulls hard to 55 in 3rd, but that's as fast as I went since it's about 20 degrees here. I'm excited since it will be 45 tomorrow. Now I can ride.

 

[Guest]

Mate that's great news! Very glad to hear it :clap:

Now time for a video

 

[isu2014]

I knew it was probably something pretty simple, so when I noticed the airbox didn't seal very well it made sense.

I'll work on a video tomorrow. The wind is blowing about 30 mph right now so my phone will have all kinds of wind noise in the background. The bike sounds good now with the baffles. I can run at high rpm without going deaf.

 

[isu2014]

She's a runner!
http://www.youtube.com/watch?v=Qp1I44E5zuo

 

[Guest]

Hey hey she sounds great! Idle's a little high thought

 

[isu2014]

Hey hey she sounds great! Idle's a little high thought

I was about to argue with you, but I got out the Haynes manual and you are correct. I thought it was supposed to be around 1750rpm, but that's only for tuning. I dropped it to around 1350 like the manual says.

 

[Guest]

Yeah the smaller ones do idle a little higher, the 450's 1100 from memory... just not as high as in your vid

 

[barnbiketom]

Congrats in the 2 banger!! ( i love 'em)

I've been following your story and wonder if you cleaned the carbs good enough? you really need to disassemble them including the emulsion tubes and DIP them in berrymans for a few hours. there's no way to really get the internal circuits clean any other say, and it sounds like it needs to get more fuel/air???
If you got to BassCliff's site you'll find a lot of tutorials on carb cleaning that will besimilar to yours!!

Well also i see there was TWO pages and I clicked on "REPLY" on the first page duoooohhhh..

but a lot of times previous owners change out jets thinking that is the problem when the Carbs are still dirty INSIDE. and o-rings are leaking air.

basically.. you never know what you got do you hahaha...

 

[isu2014]

It runs great now, so I think they're cleaned well. :?: I did what I do on every carb and always have good results, except right now I don't have an air compressor to blow out the jets and passages better. Is there a reason you think it needs more fuel/air? It pulls hard all the way to 70mph and doesn't hesitate. It idles at 1350ish rpm fine now too.

This is my first GS so I really don't know how it's supposed to run, but to me it compares to all the other old bikes I've worked on.