95 Yamaha Blaster idles but stalls when throttle is engaged

[flyersfan72]

Hello everyone. This is my first post and I'm hoping someone can point me in the right direction. I'm a novice when it comes to engines so please bear with me.

I have a 1995 Yamaha Blaster that will start up and idle but everytime I touch the throttle - whether it be a little or a lot - the RPM's drop rapidly and it will stall. If I release the throttle before it stalls the RPM's will return to idle speed. Everything on it is stock.

It's got a new plug in it and after running it this way for a little while for troubleshooting the plug looks a nice tan/brown color which I think indicates a good air/fuel mixture? I've also had the carb apart and cleaned it as best as I could...soaked in carb cleaner - ran small wire through holes and blown w/air.

I'm not sure what the float setting is supposed to be but the flat part of the float is pretty much parallel with the bowl. If anyone knows what I'm supposed to set it to I'd appreciate hearing from you so I can make sure it's set correctly. I've got a new bowl gasket and new needle valve.

I've played with the idle and mixture screws and it doesn't seem to make any difference - same exact symptom. I've taken the reeds out and looked at them - they have no cracks and seem to be ok but like I said I'm a novice and I really don't know what they're supposed to look/feel like!

It's got new gas in it. I don't have a new air filter on it but I cleaned the existing one pretty thoroughly and doused it with oil. Also tried running it briefly without the filter which didn't seem to make a difference either.

Also, just to make sure - I did a compression test and it came in consistently at around 125.

That's all the info I can think of to give you guys. If anyone has suggestions please let me know and if you need more info let me know.

Thanks in advance.

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[the_privateer]

it sounds like it is starving for fuel, check the petcock for clogs, check for air leaks, or it could be the float level, though i do not know what it should be set at.

an easy way to check the reeds if you're not sure about them, is to take them out and test them with your lungs i.e. blow into them to make sure they open, and suck in to make sure they seal (of course, set them out for a while to dry the gas and vent the fumes first)

125 psi isn't great but should be plenty to make it run, your choice of verb for oiling the air filter sounds a little much, they just need a light but thorough coat of air filter specific oil, but if it doesn't run any better without the filter on then thats not it.

[flyersfan72]

thanks for the response Privateer. Hopefully I'll have time tonight to check into the things you mentioned and I'll let you know the results.

[the_privateer]

forgot to mention the gas cap vent also, which you can easily check by taking off the cap to see if it works better, the problem is defenitely a lack of fuel, it sounds like just enough is dripping through the carb to idle and thats it. if there is no clog in the line, petcock or gas cap, and no air leak, it is most likely the float

[flyersfan72]

Alright, I finally got to work on my Blaster yesterday. Here's what I did:

Petcock not clogged.

Didn't notice any air leaks.

Checked the reeds like you said to do - they seem to be ok.

Took the carb apart again and adjusted the float level slightly to allow more gas.

As I was putting the carb back together - for what seemed like the 100th time - I looked at the two wires going into the top cover of the carb where the throttle cable comes in. Through this whole process I've wondered what those electrical wires were doing going into a carb but again - novice here so I ignored them. However, this time I decided to trace them and low and behold - they were cut! They're supposed to go all the way up to the throttle housing on the handlebar but about 6 inches from the throttle housing they were snipped in hald - clean as if done for a reason not just chewed by mice or something.

So I took a set of aligator clips and connected the two ends that go to the carb. I started it up this time and it's a least a lot closer than before - I get some response when hitting the throttle. I disconnected the aligator clips and not response from the throttle (other than a slow stall like before). So those wires server some purpose. I took the top of the carb apart where the wires lead but I couldn't figure out how exactly it works. When the throlle is disengaged, the arm that pivots makes contact right where the wires lead into so maybe it somehow senses when the throttle is engaged? Not sure.

But now what happens it it will idle fine. If if let it idle for about 10 seconds then hit the throttle about half way the rpms race up like expected then begin to drop and it kind of sputters. If I let go of the throttle and then hit it again immediately it doesn't respond well at all. If I let go of the throttle for about 10 seconds again, I can get the high rpms but then they drop away again. Is this still possibly a float problem? Am I not getting enough gas consistenly?

[flyersfan72]

sorry - forgot to mention that I did check the gas cap vent as well - didn't make a difference

[fivepointnine]

its your TORS unit, I gaurantee it, its purpose is to cut fuel flow in the event of a stuck throttle so you dont blow your engine. it is the cause of 90% of headaches for banshee/blaster owners, they sell a removal kit (not sure where, my old blaster already had it removed) but do yourself a favor and remove it however you have to, then step 2 is get rid of the oil injection, a block off kit is less than $50 and saves you the pain of your oil injection pump crapping out on you.

125 PSI is excellent compression for a stock blaster



PM me if you want more blaster/blaster mod info. I just got rid of a full race blaster so I know those things inside and out.

[flyersfan72]

Thanks fivepointnine. I think the carb cleaning was needed as well but it sure sounds like this TORS thing might be what's causing me grief now. Anyone out there know how to disable it? The local Yamaha dealer was more than willing to sell me a new part for something like $95. No thanks.

[Easy Rider]

Anyone out there know how to disable it? The local Yamaha dealer was more than willing to sell me a new part for something like $95. No thanks.

Sure, you cut the wires! (Sorry, couldn't resist.)

Ya think maybe that the disabled/removed part needs to be REPLACED by something for the bike to actually RUN ?

"No thanks." ????? You want the thing to GO or not ?

If that part replaces/disables what is causing the trouble, you may not have any choice in the matter.

I wish you luck in getting the answer you WANT to hear but I suspect it's not going to happen.

[fivepointnine]

actually to get rid of the TORS, you just have to find a carb cap and a new throttle cable and unhook the control connector under the front "hood" you will also need to drill/tap a idle control screw in your carb...mine was already done when I bought it.....try these websites for more info...........Everything2Stroke or www.blasterforum.com or planet blaster............trinity racing, duncan racing.....lots of blaster stuff.

this is a really good one too
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this was my old blaster

[marauder800]

we had the same problem on my son in laws blaster, all we did was follow the wires that come from the throttle lever, they go down under that front hood to a plug, we unplugged the thing, then cut the plug off the wires that run to the engine and spliced them together..FIXED! Just take that front hood off the machine, find where they plug together, unplug it and just get rid of the part that comes from the throttle lever, and cut the plug end off the part thats attached to the 4-wheeler and splice the wires together.

[jacob morgan]

my 01 blaster wont idle