air idle screw question

[Arnold]

So after I crashed my blaster two Sundays ago, I drove it back to the truck just fine, but I was taking it easy cause of the broken rib. When it got back to my sisters house, after a long cool down period, I started it right up n drove it across the street to my house n it sounded like it had a really bad knock in the motor. So I parked it, built a leak down tester n did a leak test. Besides a very small leak from the seal in the intake boot most likely due to the adapter I used. I found no other leaks anywhere so I put it back together and started it and took it for an easy ride(cause I'm still in pain). No air leak found n I still can't have the air screw out more then a quarter turn. Why would this be so?what could cause this? It is stock, air box lid gone n a 250 main jet with the stock idle jet n needle. I just want to make sure I don't do any damage.

Thanks in advance for all your help

Arnold

 

[Awk08]

it's possible for the floats to get knocked out of adjustment during a hard crash, i've done it

check your float level first, and while in there give the carb a good cleaning, might be some dirt partially clogging the pilot jet, hence why you have to add less air to it with the 1/2 turn airscrew

float height should be 20-21.5mm measured like this.....

and gets adjusted by bending the tab slightly........

 

[Arnold]

I actually did that awhile ago, it was out of adjustment so u adjusted it n the only thing it fixed was the fuel brimming, it has been like this since I dropped the main jet down from a 290 to a 250 should I change the clip position on the needle?

 

[Blaaster]

A #250 main seems awfully small jet to use with the lid off, and combined with an air leak it could have run on the too lean side.

I fear you may have damaged the piston.

What is your elevation?

Why did you drop the size of the main?

Did you do a plug chop to confirm that the #250 was the correct jet.

Leave the needle where it is.

 

[Arnold]

Well I put the 290 in because I bought a jet kit n that was the smallest jet in it then I got talking to people n they were saying a 250 should be about right with no mods but the lid removed. I have not had a chance to plight chop yet but I did do n leak test n it was air tight, well except for it leaking around my makeshift adapter for my tester wouldn't seat right so I have to modify it a bit. But I had no leaks anywhere else that I could see.

 

[Arnold]

Elevation is 633 ft

 

[Blaaster]

What pipe are you using and have you done any mods?

 

[Arnold]

Everything is stock n I have the lid removed.

 

[Arnold]

So blaaster should I pull the top end apart to see if the piston is damaged at all or do you think ill be fine?

 

[Blaaster]

You could pull the pipe off and look up the exhaust port to see if there is any piston or ring damage.

Also pull the reeds out and look to see if the piston skirt is complete.

It would pay to do a compression test after if the above are ok.

 

[Arnold]

Ok I took the exhaust and reed cage off last night and looked at the piston, didn't see any chunks missing, did see a wear mark on the skirt on the intake side but I'm pretty sure it was there the last time I did a tear down. I also took the right side cover off and found that my counter shaft gear is extreamly loose so I'm looking for one of those to replace it before I put it all back together. I think my problem might be my plunger n the idle screw on the tors, (wires for tors is cut) so I'm going to be ordering the tors delete and the gear and the rebuild kit tomorrow. Any other thoughts or suggestions?

 

[Arnold]

Can I do a leak test n ait cimpeessiin test with the drain plug out n the right cover off?

 

[scotj77]

that gear can make some noise in the engine. also take a look at the play in the blancer bearing(the one you can see) once you have the gear off. hmm maybe a leak in the choke circut. check out the seal on the bottom of the choke. it just unscrews from the carb

 

[scotj77]

yes you can do a leakdown that way. you should have the flywheel off also so you can check that seal if the pressure is dropping at all

 

[Arnold]

Ok ill get that done tonight n ill also post pics of the piston before I put it back together

 

[Arnold]

Ok so I didn't get the leak test done cause my seal in my new adapter had a leak. I pulled the choke out n the o ring looks good, but I did notice a crack on the out cover on the choke, will that do anything? For the hell of it I took the bowl off the Carb to check the float level(cause I did crash it last week) n found a lot of dirt in the bowl(probably from the 2 ft mud puddle I went thru). I am going to pick up some Carb cleaner n new o-rings tomorrow.

Here are the pics of the piston that I took.

The other side had no marks but I wanted some input on this.

Thanks for your help

Arnold

 

[Blaaster]

That scuffing on the piston may get a lot worse as there will be a deposit of aluminuim on the bore.

Every time the piston passes the deposit it will transfer even more aluminium.

I have seen pistons like that run in a cleaned up bore and reused but I would not tempt providence in doing it.

The skirt area is the weak link of the piston.

I would replace the piston, you may get away without a bore and just a hone if the jug is within specs.