'01 Blaster bending my mind.

[Biff]

'01 blaster stopped running well. Compression test was 65. Replaced top end, fired up for a minute and started acting like it's not getting fuel. Tried to fire it a few more times and got one pop. Fired on starting fluid once or twice, then nothing. I've got good spark, the plug is wet, the stator key has not sheared, I tore the carb down and cleared the jets, the float is functioning properly, and new stock reeds. I am befuddled.

I think someone has messed with the tors but I am not sure to what extent. There is a small button/switch that is not connected to anything near the box on top of the carb and a hole in the top of the box also. Al the tors connectors are still connected. My understanding of the tors system is that it would cut off the spark if it was malfunctioning, correct?

Re-jet?

Help me out, I am about to roll this thing off the nearest cliff.

 

[brandoz28]

first of all, leakdown test, then remove your tors.

 

[Awk08]

/\/\/\ yeah, and then retest compression, and leave that starting fluid for the family stationwagon, if it doesnt have oil mixed with it when you spray it, your essentially running it with no oil, never use it on a 2 stroke, imo

 

[Biff]

Alright. I'll have to make/ acquire a leakdown tester. If I just disconnec tthe tors connector under the front fender will that give an indication as to whether it is part of the problem?

 

[Awk08]

yes eliminate all the tors, switches, brain under the hood, cut wires at carb and thumb throttle, but a tors removal cap and cable is best

 

[Biff]

Just went down and compression tested it again and I can't get it above 30!? This is far from my first top end. Standard (stock) piston came out, cylinder looked alright, honed, piston right direction, head gasket right side up. What else could be causing me low compression? Should I pull it down again?

 

[Kgibson]

Has to be an air leak, either base or head gasket. Are you sure all the nuts are torqued down? As previously stated....leak test

 

[Awk08]

we've (ken oconnor and i) have been seeing alot of base gaskets leaking lately,
hudak just had one also, mainly the green paper ones (vito's and the k&s ones from ebay), and have come to the conclusion that the stock metal/gasket covered ones are far superior to them, also have heard good things about a certain cometic gasket from supernoober

 

[Biff]

Well, for kicks I went out and slapped the old gasket back on the base to see if there was any improvement and there was, but still not what it should be (60-70). I'm confused and worn out for the night. I will disable the tors tomorrow and perhaps track down another gasket set and start fresh.

 

[Biff]

Upon reading the thread about the '07 Blasty, could I be having problems from not having the airbox lid installed? Will it change the air enough to result in a no start situation?

 

[super noober]

Upon reading the thread about the '07 Blasty, could I be having problems from not having the airbox lid installed? Will it change the air enough to result in a no start situation?

i wouldnt think so but if you have the lid put it on and see what happens. COMETIC EST gaskets FTW!!!!!

 

[royalt67]

Alright. I'll have to make/ acquire a leakdown tester. If I just disconnec tthe tors connector under the front fender will that give an indication as to whether it is part of the problem?

Eliminate all that crap when you get a chance, but yes, just unplugging the blk/wht wire on the TORS box will disable it just fine for troubleshooting purposes.

I wouldn't think having the lid off without being properly jetted would do anything but lean you out a bit, but if you aren't jetted for it, then put it back on. Certainly there is no way this should affect compression.

You sound experienced enough, but I have to ask. Are you holding the throttle open and kicking until the comp tester stops rising (up to 20 times)?

I started using only Yamaha base gaskets on the advice of a builder. 13 bucks at the dealership.

Low compression only has three possible causes. Rings, Head and Base gaskets.

 

[royalt67]

Just went down and compression tested it again and I can't get it above 30!? This is far from my first top end. Standard (stock) piston came out, cylinder looked alright, honed, piston right direction, head gasket right side up. What else could be causing me low compression? Should I pull it down again?

Just re-read this. You just honed and ringed it right?

Did you measure and make sure it was a standard piston? If you put standard rings on a bigger piston you would get excessive ring gap.

If you honed it, what is your piston to wall clearance now? A piston can look great and still be worn out, as can the cylinder.

 

[Biff]

The piston that came out was 66mm and the one I ordered was a standard piston. didn't measure it before I put it in. At this point I'm leaning towards the cylinder looking good but needing a bore.
I did hold the throttle open but didn't give it 20 kicks. I'll assess further.
I think I will take that advice and use some stock gaskets also. Thanks for the input fellas. I'll update when anything changes.