First Bike - 81 Suzuki GS250T Issue

[Guest]

I recently picked up a nice clean 81 Suzuki GS250T with 8k miles for $400. It's my first bike and I thought it would be perfect to learn how to work on Motorcycles (I am a noob) and to learn to ride on (never ridden a motorcycle before)
I bought the bike not running, The previous owner stated that it had a bad starter but didn't have the time or interest to replace it.
I figured it would be a pretty straight forward fix so I decided to purchase the bike.
I jumped the solenoid with my car and the engine rolled right over right away, so I was able to determine that the starter was not the issue.
I took the battery to Farm & Fleet and they stated that the battery was no longer any good and that even if it was good; it was not the right battery for this model bike. I obviously purchased a new battery that matched original specs.
I also ran a new starter cable from the battery to the solenoid and a new ground wire. (all connections are tight)
The bike now turns over just fine and everything was looking good so I put some gas/seafoam in the tank and tried to start it.. The engine didn't fire.
I determined that the carbs must be gunked up so I took them apart. Carbs were pretty clean and the floats did not appear to be stuck.. Regardless, I cleaned the **** out of them and found that the jets were plugged. I cleaned them out with a guitar string and got the carbs damn near spotless and put them back on the bike.
I checked for spark and we have sharp blue sparks firing on each cylinder. So that's looking good.
I was pumped to finally get Suzi up and running so I threw the battery back on, sprayed some starter fluid in the carbs and pushed the start... Bike fired right up! I was ****ing stoked after all the time I'd put into it!
Problem is.. As soon as I let go of the Starter button the engine dies.. When I try to start it, it will start just fine and as long as I hold the button I can rev it up but when I let off the button, it dies.
I don't want to continue running the starter while the bike is running because I am scared to burn up the starter. I have looked online and I also have a original service manual but cannot seem to find anything addressing this issue.
Any thoughts?

[tom203]

"...As soon as I let go of the Starter button the engine dies.. When I try to start it, it will start just fine and as long as I hold the button I can rev it up but when I let off ..."

Might be bad wiring in starter button and "run/off" switch area- maybe miswired by creative PO. Go here and scroll to end for a wiring diagram to check stuff. Best to NOT let starter staying engaged with engine reving!

A multimeter is a must-have suzuki accessory

http://www.mtsac.edu/~cliff/storage/gs/GSX400_GS450_wiring.pdf

[Gorminrider]

I wonder if it's a compression issue? Seems like the engine firing hasn't enough guts to keep itself spinning. So it's something I would check just to get it off the list of possibles.

Valves stuck or plain wrong? I think your valves are easy ones to check/adjust...no shims just lock-nut adjusters. Ring problems seem less likely but...

maybe have a look at the timing too....got a timing light? It's not adjustable but centrifigal advance mechanism might be stuck in full advance mode though I think it's pretty rare as it's so simple a mechanism.

[Larry D]

Welcome !!

Adjust the valves. Hard or difficult starting is a telltale sign of valves out of spec.

[850 Combat]

First, clean the carbs per the instructions in Bile Cliff's site. Poking the crap out of the jets is helpful, but does not complete the work. Second, determine if it loses spark without the starter button pressed. You shouldn't, of course.

[Dallasabx]

Thank you for your advice. Is their a complete carb cleaning walkthrough on Bile Cliff's site?

Also, do you have the URL?

[Dallasabx]

Regarding ajustment of the valves.. Should I take it to a shop considering that im a noob or is this something I could do myself?

[JTGS850GL]

You can do them yourself. It's a piece of cake. Just follow the instructions here:

Valve adjustment for 16V engine

You only have 8 valves but the concept is the same since it's still a 2 valve per cylinder engine.

Here's a link to the factory service manual that will help you as well:

FSM for GS250T

[robertbarr]

My vote is also for an examination of the wiring. Remove the tank, put a voltmeter on the + side of the coil and switch the ignition on. Volts? Yes, no? Press the starter for a few seconds. Volts now? Yes, no?

An analog meter would actually be better for this, or a decent digital with the pseudo-analog bar graph.