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Discussion Starter #1
I just picked up a 1989 VTR250, it had been sitting on the side of the road in brooklyn, uncovered, for TWO year. but the deal was to sweet to say no. so i picked it up midday saturday, and spent the day working on it, and brought it back to life.
She idols, I got it up to 50 in second gear before i hit a red light. the joys of city living.

However before it gets there is had tremendous trouble getting off the line. I would compare it to riding a moped. I am literally pulling the throttle all the way back, and from a complete stop it will crawl for a good 30-50 yards, before it starts to pick up speed.

I must admit though, I haven't cleaned the carbs. though a few folks around the garage don't believe it be a carb issue, as there aren't any other issues that would suggest something to be wrong with them. (even still they are going to get a strong cleaning by the weeks end) One thing I have noticed is that the temp gauge is not registering anything, the gauge needle works, so i believe it to be the actual 'thermometer' to be busted. Not sure if that would have anything to do with my issue.

Anyone experience anything like this? any ideas of what it might be?

I cant wait to get this 'beast' fully functional, when its actually moving, its pretty fun and really seems like like it wants to corner and just live on twisty roads.
 

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I was at the garage and said it was carbs,....think ghetto said so too.
There was a smell of fuel but that could have been a lot of the bikes there...lol

Im willing to bet that the 250 runs a "CV" type carb and im more willing to bet that the diaphragm is stuck or ripped.
The bike was only idling on one cylinder. didn't really hear if the other was picking up at higher RPM
Carbs aren't that bad to take off on that bike
take you time and make sure that ALL of the passages are clear...there are a few that are hard to check....
Get a factory manual and find our the specs for the needles

good way to tell how the motor is running is to get new plugs and read them after some riding or a plug chop
Also try pulling the wires off each cylinder and see how the motor reacts. if its idling on one then when you pull one wire nothing will happen and the bike will stall when you pull the other
 

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For the record, I asked if they were CV carbs and did you check the vacuum passages and carb diaphrams. I reved it and it reved fine on the stand but under a load the slide may not have been popping up. then someone said something else and we forgot about the carb issue.

also check the timing, specifically the advance mechanism. If it were out of time slightly, it would dog off the line and then pick up as the revs increased.
 

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Think about what makes and engine work and then think about what would happen if you let it sit...

Motor works like this...
Suck Squeeze Bang Blow.....4 strokes.....
The suck and the blow are kind of easy to check, is the motor turning over? Yes? well then the piston is sucking and blowing air....
Well how well is the motor doing this? thats also easy to check, by measuring the squeeze, this would be your standard compression test.
now we get to the fun part, the Bang
This is a two part section. Part one you need fuel and part to you need spark. Yes all of this friday night fun needs to happen as very specific times but always start at the basics and work your way through the system.

Best to start with easy stuff.
Do a cylinder drop test like i told you by pulling the spark plug wires off and see what happens.
This will narrow your issue down to one cylinder
Then run a compression test and see if both numbers are with in spec
Then get a "spark tester" its a light that you put in line with the spark plug wires and the cylinders, IF the plugs are getting spark then the bulb in the tester will light up.

IF you have good compression and good spark on both cylinders then its our good friend fuel.
Fuel goes bad VERY quickly in a motorcycle tank so its a good place to start....
shake the crap out of the bike and then pull a few OZ of fuel from the petcock and put it in something clear.....sit and wait a few minutes.....if it looks like oil and water your fuel is bad and you need to remove all of it and start fresh....NO NONE of those additives will reverse this.....just pour out all of the $5 fuel and get fresh.
If the fuel is alright......its time to clean the carbs....ready GO.

More likely then not the carbs need some attention from sitting anyway
Then after you have gone through the bike its time to tune/time everything
new plugs and sit with the manual and time the bike.
 

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quote:Originally posted by jaguar

Suck Squeeze Bang Blow.....
Didn't one of the chopper shops in Hell's Kitchen used to offer t-shirts with this printed on it? I always regretted not getting one to wear to church or something....

Jim
 

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Discussion Starter #6
I disagree on it running on one cylinder. As it has power, just not right off the line. pretty much after it passes the intersection, it builds up speed and then is fine. Like i side earlier I got it to 50 in second gear, I don't think if it was running on one cylinder it would be able to do that at all.

Even though I disagree I'll start with a spark plug check, then ill do a compression test, move to timing, and I'll end with a hugh carb cleaning, and look for any pin hole/rips in the diaphragm.

I am also looking in to the thermoswitch, as the temp gauge wasn't working at all.
 

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Always start with the basics

It can be idling on one and the other can pick up as REVs increase causing a slow get away but ultimately getting to a OK speed.

Get larry and the guys to invest into a soda blaster....its my new favorite thing....
 

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What that says is that the pilot jet circuit is blocked on one cylinder but teh main jets are not.

Strip and clean both carbs and check all the tiny holes. If that doesn't fix it, start to check more serious things like compression.
 
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