theckeler

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Feb 1, 2009
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I recently did the top end on my bike (all new... 66mm piston, rings, gaskets, wrist pin, etc), and removed the kickstarter (see *) internals and replaced with one that worked. I've been working on fixing up the electrical (**), starting the bike to test it on a multimeter, must have restarted it about 4 times and on the 5th I tried to start it and it felt off. The slip on the kick was back, not so bad as before, felt like the compression was off and got an odd poooof sound from the muffler. I still haven't been able to start it. I removed the plug, check spark, it's there... put my finger into the plug hole felt compression (have no gauge yet)... put a screwdriver into the hole and felt the piston go up/down no problem. My plan is to get a compression tester and make sure it's good but wondering if anyone would know what's going on. I have another thread going in another forum and got some good feedback but think I need more. Thanks.

Oh and I did other random things as well, new throttle cable, cleaned the carb, power reeds, and cleaned the airbox.

* Kicker slipping, before replaced, I would need to kick slowly and find a particular spot then kick it to start. Took a while to get it going if you needed to kick a few times and once you missed the spot you needed to go back and find it again. I assumed it was the ratchet in the rear was slipping out of place and only had a few good spots, why I removed the whole shaft and replaced it with one that that worked.

** Replaced the harness and added a vol reg. and light on the front since all of it was removed for dual sport stuff that was detroyed.
 

julien_d

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Oct 28, 2008
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On the other forum I read you did the top end at the same time. The only thing that jumped to mind with the "poof" sound was the piston and rings. The piston is directional. Did you install it with the arrow on top pointing to the exhaust port? Also, check head and base gasket for proper seal.

J.
 

whenfoxforks-ruled

Old MX Racer
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Oct 19, 2006
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I would be concerned with the bottom end being sealed up. You will need a leak down kit, or jury rig of the same purpose. I am thinking if it was a head gasket, you would have heard it there.
 

theckeler

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Feb 1, 2009
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julien_d said:
On the other forum I read you did the top end at the same time. The only thing that jumped to mind with the "poof" sound was the piston and rings. The piston is directional. Did you install it with the arrow on top pointing to the exhaust port? Also, check head and base gasket for proper seal.


Ya installed with arrow to the front of the bike, towards the port... I replaced the gaskets with new ones. Do they sometimes lose compression after a while? Did I need to add grease to the seal as well? Going today maybe to get a tester so i can see what is going on.
 

theckeler

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Feb 1, 2009
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whenfoxforks-ruled said:
I would be concerned with the bottom end being sealed up. You will need a leak down kit, or jury rig of the same purpose. I am thinking if it was a head gasket, you would have heard it there.

Not sure what you mean... new to fixing bikes. At this point should I just take it to a pro?
 

whenfoxforks-ruled

Old MX Racer
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Oct 19, 2006
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Merrillville,Indiana
Do a search on a leak down test. Taking it to a shop, good luck! If the shop is good, they would charge a nominal fee and test it. If you rebuilt the top end already, you can do the rest also.
 

theckeler

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Feb 1, 2009
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whenfoxforks-ruled said:
Do a search on a leak down test. Taking it to a shop, good luck! If the shop is good, they would charge a nominal fee and test it. If you rebuilt the top end already, you can do the rest also.

Just getting frustrated... Ya they want $100 to evaluate it and tell me what's wrong. Hoping it's just something simple. Replacing a piston I understand that it's sometimes good to resleeve it or bore it out, do you think that might be my issue too much gap between the cylinder and the rings? Also, when I installed the rings I put them to their proper spot (where the indicators where at), but think they might have moved a little because I had to sort of twist the cylinder back on, think that would do anything?

Thanks for everyone's help!
 

aaronnaland

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Jan 19, 2009
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if you have exhaust valves you should check and see if there sitting open all the time when they get old they can stick and on a few of the older versions of powervalves its a common problem. they should open wider as your rpms go up and if your rpms are low and they are wide open i have heard it make weird poof sounds.
 

whenfoxforks-ruled

Old MX Racer
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Oct 19, 2006
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Twisting the cylinder is a big no no. The ring can snag, and sometimes force the pin in that holds the ring in place. Visual inspection, check the ring end gap and skirt clearance. If the cylinder has issues, send it to Eric at Forward Motion. There is a video out there showing how to do a leak down test. The kit would only set you back a little more than he SAYS he is going to charge you anyways. 2 strokes and that tool is priceless.
 

sr5bidder

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Oct 27, 2008
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I would not be so quick to spend on the tester just yet.
are you sure your getting fuel?
Also did you deglaze the cylinder at all?

You sound pretty good at electrical work so I'm sure you put that regulator on the lighting coil circuit right?
 

theckeler

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Feb 1, 2009
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sr5bidder said:
I would not be so quick to spend on the tester just yet.
are you sure your getting fuel?
Also did you deglaze the cylinder at all?

You sound pretty good at electrical work so I'm sure you put that regulator on the lighting coil circuit right?

Pretty sure, I pulled the plug and it was sort wet... one odd thing and I can't remember if it was doing it beforehand was gas escaping the hose to the carb and down the side of it a little. Figured it was a common thing and since the hose is held down by twisted wire it doesn't have a good seal. I'm starting to think it has something to do with the gas... and something to do with that damn slipping of the kick (can't get a good kick on it). Going to drop some clean gas into the plug area in the next couple days and see if it fires when I try to bump it in the garage. Could the poof sound be a sort of backfire? There is quite a bit of oil from the muffler too, mind you it's SUPER old and probably needs repack or tossed in the trash. I am running the gas at 40:1 which I understand isn't correct (was told the wrong info from the seller), but I have about 4 gals mixed already ha... Is there was way to check if the gas is getting into the carb/cylinder? Maybe it's just flooded really bad? It was warm when I tried to restart it and in the past it would start on the first kick after warm.

Ya took it into a engine shop (local car racing place) and the guy honed it out. He did say it was difficult to get the teeth into it but he got it. I could see the hatch marks on it.

Not too good at electrical ha... but ya hooked it all good, the stuff I got the guy said worked just fine as well. Really simple to hook up the wiring since there isn't much ha... I didn't disconnect any of the other wiring just the lighting when I was testing it.
 

whenfoxforks-ruled

Old MX Racer
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Oct 19, 2006
8,129
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Merrillville,Indiana
sr5bidder said:
I would not be so quick to spend on the tester just yet.
are you sure your getting fuel?
Also did you deglaze the cylinder at all?

You sound pretty good at electrical work so I'm sure you put that regulator on the lighting coil circuit right?
Never a risky adventure investing in tools. And like I said, a 2 stroke with issues, the leak down tester IS priceless for diagnosis. That poof could have been a lot of things, and it could have been the bottom end losing pressure, be it a gasket or seal. and the gas spewing out the overflow, replace the float valve and seat if applicable, clean and inspect the carb, and float height. Spewing unwanted fuel into the engine will cause you problems that you describe?
 

theckeler

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Feb 1, 2009
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whenfoxforks-ruled said:
Never a risky adventure investing in tools. And like I said, a 2 stroke with issues, the leak down tester IS priceless for diagnosis. That poof could have been a lot of things, and it could have been the bottom end losing pressure, be it a gasket or seal. and the gas spewing out the overflow, replace the float valve and seat if applicable, clean and inspect the carb, and float height. Spewing unwanted fuel into the engine will cause you problems that you describe?

Ya think I might snag one anyhow, $30 at Harbor isn't bad at all... I just had the carb out to replace the throttle cable and reeds (which I did the top end), while I was at it I cleaned it. I'll pop it out again and double check it though, only takes a second. I did readjust the idle air screw, setting it to the manual specs, 1.5 turns from seat... then moved the throttle stop in to idle the bike, it was way out. I've done so much to this bike at once that it could be a bunch of different things I guess. There doesn't seem to be any gas from overflows.

Thanks everyone for their help so far.
 

whenfoxforks-ruled

Old MX Racer
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Oct 19, 2006
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Merrillville,Indiana
By the book, that float valve is supposed to be replaced yearly. It causes problems, yet seems okay. The first 2 things to look for on poorly running 2 strokes, top and bottom pressure okay. Then if the jetting seems screwy, or abnormally rich, replace the float valve. I seen 1 of these green things for sale by my house. It would look like fun!
 

sr5bidder

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Oct 27, 2008
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yeah thats the problem doing to many things at one time I see alot of people getting in trouble like that. The hone may have been overkill, julien_d or lemmy, if I remember correctly, just used a scotch brite pad to lightly deglaze the cylinder.

I would also check the reeds agian and make sure the backing plates are in correctly.

Two strokes are pretty easy to get started even if the engine has lower than normal stats they just don't tune or run well
 

theckeler

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Feb 1, 2009
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sr5bidder said:
yeah thats the problem doing to many things at one time I see alot of people getting in trouble like that. The hone may have been overkill, julien_d or lemmy, if I remember correctly, just used a scotch brite pad to lightly deglaze the cylinder.

I would also check the reeds agian and make sure the backing plates are in correctly.

Two strokes are pretty easy to get started even if the engine has lower than normal stats they just don't tune or run well

Ya there was quite a bit wrong with it. I knew it wasn't the best idea doing it all at once but putting all the stuff back on, adding the fluid, check the kick and then removing it to repeat seemed like way too much work ha...

Just found out about the honing... the reeds where replaced with power reeds, no backing cept for a small piece of metal but I thought I would pull them anyhow and check. Going to remove the carb again and double check it anyhow, the float and condition.
 

julien_d

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Oct 28, 2008
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Yeah, the 200/220 cylinders with plating should not be honed. Honing can cause the plating to chip off badly around the exhaust ports. You might want to take a look at your cylinder and be sure the plating is still intact around the ports and such.

I have read several posts indicating that you could hone lightly with a diamond ball hone. I'm not sure I would try it unless I absolutely had to. A scotch bright pad worked wonders for mine!

J.
 

theckeler

Member
Feb 1, 2009
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Quick update... I don't have the cash yet for the leak tester but I figured I'd try to drop in a new plug (gotta get some clean gas in the can to drop a little in the plug hole so I was out in the garage) and give it a try. When I pulled the plug it was pretty wet, after I put in the new one it was doing the same no start, poof sound. But what's interesting is that I took it off the jack, pop'd it in first to try and bump it, pulled in the clutch and it didn't roll. No clutch... I did remove it when I pulled the kick but put it all back together the same way I removed it, so not sure what is going on there. Man, I really messed this bike up ha...
 

theckeler

Member
Feb 1, 2009
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Thanks, right after I posted it I checked some forums and ya looks like they might just be stuck. Weather is going to get good this weekend and next week, hoping to can run it down the slight incline here and bump it to a start.
 

MOgle80

Member
Dec 4, 2005
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actually I bet the clutch will be fine when the motor gets started in neutral. get those clutch plates all whirling around in the oil real good as long as there is no warped ones.
 

jason33

Member
Oct 21, 2006
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that poof is it tryin to start ,keep tryin!
clutches - hold the clutch lever in for a while after starting it,
if it has been settin! for a long time, the pilot jet in the carb (little jet deep in the case under the bowl) is clogged , its the starter,and idle jet
 
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