New topend To bad topend. Possibly Help me lil disapointed.

[1995blaster]

Well long story short. I got a top end with very few hours on it put it on, Yes i put the rings on right etc.they are bent. Well I had it jetted to the same as before the new top end. I re tightened all the bolts after a few warm ups etc.... Drove it in my yard ran great. It felt by the kicker that it had tons more compression then my other bike. I took it on a weekend ride. First night was only an hour of riding ran great. Second day i took it for a big long ride ran great, hour or so later took it out for another ride it was hard to really gain rpm's and sounded boggy also when it idled down when it would make the obvious 2 stroke crack as it went down i would hear a slapping noise. I stopped after about 6 minutes of it doing that. I went to start it and the kicker had almost no compression and did start i got towed back and the reeds was bad(still had low compression) went on a ride still made the piston slap noise but ran great later in that ride i lost power and couldnt revv it up like i should. What could of caused this it didnt have hangy rev's or andthing?

Still starts really well checked the reeds again and there good. Not sure whats the deal.

 

[Awk08]

did you use all new gaskets when assembling this topend ????
what did the original leak down test show ????
what did the new leak down test show after changing the reeds ????
anytime any gasket that seals the motor is removed/changed, a new leakdown test is a must ?????
what did the compression test show ????
did you clean the carb while apart ???
how bout the airfilter ????
try changing the plug ????

 

[1995blaster]

did you use all new gaskets when assembling this topend Yes
what did the original leak down test show cant rememeber but was good
what did the new leak down test show after changing the reeds
anytime any gasket that seals the motor is removed/changed, a new leakdown test is a must was on a trail and didnt have it but did use silicone
what did the compression test show havent done one but i can push it down with my thumb.
did you clean the carb while apart no on a trail would of gotten dirtier
how bout the airfilter it was cleaned before the ride so didnt have but a few hours on it and was dry as a bone.
try changing the plug i did try that but i only had a old plug on me didnt work so i checked the reeds and they were bad then finished out the weekend

 

[Awk08]

so, did you allow the silicon to dry/cure before running it again ???
the vaccuum will draw in wet silicon
was it gasoline proof silicon ???
did you pull the reeds again to see if the "newer" ones broke ????

and i meant "did you clean the carb when first installing the new topend" ????

is the oil injection inlet plugged on the carb ????

 

[1995blaster]

so, did you allow the silicon to dry/cure before running it again
the vaccuum will draw in wet silicon no
was it gasoline proof silicon yes and high heat its orange stuff
did you pull the reeds again to see if the "newer" ones broke yes there still good. They have a lil 1/16 inch gap on one need to be replaced before they break but thats shouldnt make the bike run like this should it? or make less compression

 

[Sonia_69]

If you used the copper high temp sealant it takes 24 hrs to completely dry.... I just made the mistake of not waiting long enough doin my upgrades and it caused 2 stroke and gas to leak from the bottom of the reeds.... Oops So I had to completely redo it. Maybe riding it with the airleak caused your problems???? Also my blaster was really hard to start before I did my upgrades, after i cleaning my carb and added my goods on it started 1-2 kicks easy now, it seems to have affected my compression doin that stuff, for the better though in my case, cuz it used to take bout 15 kicks for it to finally start up, cold that is.

 

[1995blaster]

Mine starts up 1 maybe second kick every time almost since i got it and still does. Could the reeds having that gap make the seal of the engine be lost through the carb? You would think with a lil suction the reed would move and seal up.

 

[Awk08]

yes the reeds hanging open/not closing the whole way will make it hard to start, and sh*tty compression
after pulling them....see if you have compression then

 

[Blaaster]

How are the head bolts, you stated you tightened all the bolts after a few warmups, were they proper heat cycles, if not the head gasket could be leaky.

 

[Awk08]

another leakdown test will provide alot of answers

what base gasket was used, hopefully stock or cometic, and not a green kindergarden construction paper one

are you bullshitting us about the leakdown test ????
as in...do you even have one ????

 

[1995blaster]

I tightened them up after a few heat cycles and riding around in my yard. I took a flash light and looked between the fins and saw copper all the way around so i think im good shouldnt have a head leak would prob be black.

When i had the reeds intake boot and carb etc off the compression feels the same as if it was on. And yeah it was a cheap tusk one.

 

[Blaaster]

What about that slapping noise, is it there all the time, does it come and go, when the motor runs well does it still slap?

Compression may feel the same , but the only way to test it is with a tester.

 

[1995blaster]

It goes with the revs it started right before the reeds went bad and still afterwords. and the kicker i can push down with my thumb it may still be about 120 but is still not close to were it was i might be able to fix what is wrong and not have to replace a topend.

 

[Blaaster]

Just a thought, could it have got overheated and the piston put some aluminum on the bore. This would account for loss of compression as the rings would not be seating.
The slap could also be explained by a worn piston skirt.

How is the lubrication, drop the pipe off and look at the piston, you should get some idea if there is any damage in there.

 

[1995blaster]

i can see the intake port side of the piston there is a few very fine scratches but i used a flash light in dim lighting so im sure it exaggerated the scratches and they still seemed fine.

 

[Blaaster]

Pull the pipe and report back.