Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[albertinhouston]

Bought an 08 gt250r with a bad motor. It's a super clean bike. pulled the head off and no piston no connecting rod. Bike only sat one month. I cleaned the carbs anyway.
I'll try to keep it very brief.

Bike idles on choke ONLY that's it if remove choke it dies.
I give any gas it dies it bog's and dies.

below is brief recap of my weekend.

swapped the motor from the 07(motor tested good) to the 08.
- front cylinder not firing / gas.
--- did some swapping of parts (swapped carbs plugs cdi coils harness) got the front cylinder to get half hot. water wouldn't bubble off when sprayed on it.

did another motor swap from an 09( motor tested good ).
- front  header is not heating as it should.
--I took from the 09 the full harness, carbs(3), cdi(2), coils(2), rectifier, fuel pump, separate tank, another complete exhaust, new fuel petcock, and filter..
 I have literally tried 3 separate carbs on the bike.
 I was thinking there was a problem with the wiring harness
 maybe the fuel pump part clogged.
 maybe exhaust was clogged with parts of the piston and that was preventing flow issues.
 maybe tank was dirty.
 coils- because they always go out.
I didn't mention plugs or stator as those were changed when I did the motor swap.

So in short, I think I pretty much changed everything I can think of that would effect this.
I really thought it was going to be a harness issue after I swapped all of those parts.

And just to confirm the carbs were good I put them on another 250 and it fired right up and ran just fine.

Register and log in and the Ads below will be gone! :D

[Dojy_biker]

if the exhaust is the only common part then change it, or test run without it.

[albertinhouston]

that was swapped as well.
 I even swapped the battery just in case. I was really stretching at that point.

Those only things I didn't swap are. starter solenoid, battery cables, right/left hand controls

I even by passed the said stand and clutch safety switches. changed air boxes filters no air box.

If I partially covered the carbs with my hand, I could get a little RPM out of it but not much. Then it would die.

 I'm about to change the rear brake bulb to see if that's the issue.  Hell at this point it's worth a  shot!!!  (totally kidding by the way)

[umop-ǝpisdn]

May be worth matching the CDI and flywheel. Is the pickup coil correctly connected?

[albertinhouston]

When I did the 2nd motor swap, I used all the 2009 donor bike parts. motor, carb, CDI, stator, rect. relays, wiring.
That's why I'm so baffled right now.

 I'm going to change the all the battery cables and grounds next time I mess with it.

[umop-ǝpisdn]

Any chance that a manifold somewhere isn't quite sealed? A vacuum leak sounds plausible with those symptoms.

[Dojy_biker]

definately sure you have a carby rotor and carby cdi.?.. my understanding is that it wont work so well if you get them mixed up

[albertinhouston]

Any chance that a manifold somewhere isn't quite sealed? A vacuum leak sounds plausible with those symptoms.

I'll double check. But the current motor I have in there ran just fine in it's original frame and for the other good motor to have and cracked/ unsealed mani. on the same cylinder is a little unlikely. BUT! I did consider it and I checked by blowing air through it under water to see if any bubbles came up.

definately sure you have a carby rotor and carby cdi.?.. my understanding is that it wont work so well if you get them mixed up

Unfortunately I'm 100% positive these are the right combo.

 I spent most of my night thinking about possibilities... I didn't come up with much. So aggravating! lol

[albertinhouston]

OK!
THIS FREAKIN BIKE!....
So I pulled it out of the corner of the garage since I put it there a month ago.

so I hooked up a ninja 250 tank to the bike and the PHUKER started and rev'd up like it should. The back exhaust whats heating up(spit test) but I was running. pulled the carbs to check them. looked good.

Put the carbs, air box back on and same ninja tank. and back to square one.  FML!!!! like for real. lol

so the only different was the air box.  not being on the first time.
when I bought the bike it didn't have a filter in the box. I was thinking maybe the carbs are actually jetted to run this way.  so when I restrict it with an air filter it's flooding out(too rich) when I give it throttle.

I think really I'm just trying to document what if tried more than looking for answers. 
 I'll give it another go when I get home

[umop-ǝpisdn]

Stock jets and try again?