Suzuki Quadracer HQ
LT250R Quadracer => LT250R - Engine => Topic started by: Rytie77 on June 18, 2013, 01:41:50 pm
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Hi iam new hear I just had my motor redone I get it home and start putting everthing back together I put the kick start push down on it and goes up and stops in pull head and it moves up and down put head on no nuts and the piston hits head can I run to base gaskets and what will that change thank u
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Hi iam new hear I just had my motor redone I get it home and start putting everthing back together I put the kick start push down on it and goes up and stops in pull head and it moves up and down put head on no nuts and the piston hits head can I run to base gaskets and what will that change thank u
There is a reason why the piston is hitting the head. Do not just start stacking gaskets to stop the piston from hitting the head. There may be other problems.
Did you talk to the guy that rebuilt the engine?
Was the head milled?
Do you have the wrong piston?
Was the connecting rod changed?
Was the cylinder base or head gasket surface machined?
Did you bore the cylinder? If so how much was it over-bored?
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^^^Mr Hall covered everything.
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With each question Jerry asked, it points to different aspects of the engine to look into. So if you can help him pin it down you'll be riding again a lot sooner
P*
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Thank u for responding ok has a new hod rod crank was bored over not sure how much and not sure if it was milled I called the guy who built it and no call back but I put piston all the way down in the stroke and it looks like its perfectly level with the exhaust port
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Thank u for responding ok has a new hod rod crank was bored over not sure how much and not sure if it was milled I called the guy who built it and no call back but I put piston all the way down in the stroke and it looks like its perfectly level with the exhaust port
Does the edge of the piston rise above the top of the cylinder when the piston is at top dead center? If so, is the hole in the head gasket large enough for the piston?
If the piston will go through the head gasket is the step in the head at the outside of the squish band larger than the piston?
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It does not hit gaskit the edge of piston comes out of the cly a little but then drops back in the cly
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Get us some pic so we can see what your talking about.Pics help us help you.
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get some calipers and measure the bore of the dome and the bore of the cylinder.
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The piston pots out of the cly then drops below
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What is the piston size? What is the number on top of the piston?
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Nice looking Jug - O0
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The finish on those cases looks killer too
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Piston number 9328e. Top number bottom 571m06850
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Thanks guys have a lot of time in this thing hope to have it running soon here is the hole quad
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you could measure from BDCto the top of the sleeve. i bet the cyl has been milled way to much on the top. did you pc the cylinder? looks like a custom dome is in order. from my cell phone the piston looks to be out the hole by .060. thats alot!
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On a good note, that chassis looks awesome! Cant wait to see this completed!
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Thanks hope it will be done soon yes it is pc hole quad is pc the motor is holding me up were would one get a custom dome
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now im on a computer and it doesnt stick out as much as i thought. the liner was making me think it was sticking out further than what it is. do you have an oem head or do you have a pro design?
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I do not will a pro design
Help or i can try to find a head
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The first picture appears to show the piston sitting above the sleeve, I've looked at it numerous times trying to see if it was just an optical trick, but I think that's where your problem is.
Try this....
-Get some thick grease and smear it thinly all over the top of the piston (make sure you get all the way to the very edge of the piston!).
-Install head with gasket and snug the nuts down (don't torque).
-Bring the piston up until it hits the head.
-Remove head and observe where the grease was left (or where the grease was squished off the piston), this will tell you where the piston is hitting and can give us more info to diagnose your problem.
-Take a picture of any findings and post here, then wipe the grease off to prevent spark plug fouling later on.
One of the things it will tell us is if the piston is hitting the head or the head gasket, another thing it will tell us is if the head itself is cut correctly or not (well, partially anyway).
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Ok I will do that when I get home I did throw a another base gasket on just to see if it would help with the head just siting it didn't I tighted it down and it would just hit
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Rytie,
There should be a number 86mm through 89.5mm on the top of the piston, what is that number?
I assume this is a weisco?
Also what is the max diameter of the head gasket your using in MM (use digital calipers $10 a Harbor Freight).
If the pics shown are TDC it does not look like your piston is coming too far out, could just be the head, has it been modified or is it stock?
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This is what's on top Piston number 9328e. Top number bottom 571m06850
I bought it like this but had it bored and new piston I didt ask them to modified it at all
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The last 5 digits tell you the size ... 08650 = 86.5 mm
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So I should have a few bores left
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Yeah all the way up to 89.5 (Y)
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its a 250. the piston is a 68.50mm
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Hes got one bore left. Call Cometic and order an oversize (big bore) gasket for a 87-92 LT 250.
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Oh man .... Where are my glasses!
Geeze :)) :)) :))
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What will the big bore kit do for me
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Some say more power. But not much.
Good porting and pipe combo is better than a normal big bore kit.
That, and give you head gasket problems.
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Get you a set vforce 2 or 3 s and Scp pipe and some porting you have a strong lt250r. Hey what brand of headgasket are you using i dont think this question was asked.
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K&s gaskits
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.
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Get the cometics and save yourself a lot of trouble.
www.cometic.com
Or Mitch might have some in the store section, not sure if he carried 250 gaskets though.
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I use OEM. _^_
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So u think I need bigger head gaskit
I still have to so a few test that were posted a few post ago
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So u think I need bigger head gaskit
I still have to so a few test that were posted a few post ago
Have you ever tried to read your own post?
D?
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I use oem gaskets. They are already made for the last bore so you can use them on 67mm or 69mm with no problems.
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Had a friend come by and check this motor out for me me is a 2 stroke guy he took some measure ments he said that with the cly has to come up about .80 to make it stop hitting the head that's about 4 base gaskits is that ok don't sound ok to me
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i wouldnt do it. Just get a thicker head gasket or custom dome made. stacking gaskets will off set port timing.
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What if the cylinder has been decked that much? That many base gaskets would put the timing back where it's supposed to be. Anyone got port timing for the 250?
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I asked him he said my port timing should be dead on I called cometic they said they could make me a spacer in stead stacking gaskits
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Had a friend come by and check this motor out for me me is a 2 stroke guy he took some measure ments he said that with the cly has to come up about .80 to make it stop hitting the head that's about 4 base gaskits is that ok don't sound ok to me
.80 mm is about 1 1/2 base gaskets. .080 inches is about 4 base gaskets.
What did your engine builder do to your engine when he worked on it. Why would he machine the head gasket surface or base gasket surface that much?
Did he put a stroker crank in it?
I asked him he said my port timing should be dead on I called cometic they said they could make me a spacer in stead stacking gaskits
I think I smell a rat.
Talk to your builder and find out what he did to your engine and WHY !!!!!!!!!
I
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Sounds like Darahji's builder made it over to the States.. Bubble gum and super glue, makes for the bestest epoxy ever!
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He did not stroke it i bought this quad the motor was in a box I had it bored and new crank that was it so I don't no y it's so far off
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thats unfortunate. probably why the motor was in a box when you got it.
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Iam sure lol but I now have a lot of time in this quad so iam sure it will all work out
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1. Get a die grinder.
2. Push piston to TDC.
3. Grind until nothing hits.
4. ??????
5. PROFIT.
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Really you need to remove the cylinder and have it measured by a pro or try it yourself if you think you ca do it right.
Ice racer should be able to guide you in the right direction as to how tall the cylinder should be from base to top deck.
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think the base is ok. he said at bdc it was even with the bottom of the ex port. its just at tdc it hangs out, which like jerry said. does it have a long rod, stroker crank or wrong piston. says it doent have any of that so the top of the cyl has had to much removed. at tdc it sticks out the hole.
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Spend $20-$30 on a decent micrometer. You will use it many many times. I dont know what the exact # s are. But i know the factory suzuki manual will tell you the cylinder and sleeve heights. Measure them or have a pro check it.
You said that the piston is covering the exhaust port just before TDC but at what degree on the crank rotation is that? Without a degree wheel you cant know if the port timing is correct.
I also wonder about the PC on the cylinder.. It looks great but often PC'd cylinders need redecking afterwards due to the baking heat of the PC. Could your builder have decked too much to compensate for the distortion of the base or head surface after the PC was cured?
Im kind of echoing others here... You need to get very specific answers from the builder to find out whats up. And take it from there. I suspect the cylinder was far from true on either the base, head or both sides and material was removed to square it up.
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Sorry just saw you were saying the piston was BTDC on that. Im not sure of what the measurement or position of the piston should be on the 250 at BTDC, but i do remember very detailed pics and measurements from my factory 90 250 manual.
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Ok so I took some mesurements hope I did it rite my cly from the top base to the bottom base was 4.8 830 came across another cly it was 4.9 260 in MM mine was 123.78 the other cly is 124.77
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That's 43 thousandths of an inch, and 0.99 of a millimeter. Might as well be a mile! 0>me
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Spacer Plate or a Custom Head -
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Having a plate made and hope it does the trick thanks guys for all the input
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It will work! +k2
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Be sure and measure the bore the head is set up for. You spacer plate will work fine to +- zero out the piston to top of cylinder. It sounds like you have a couple common issues, stock head that hasn't been chambered properly for the bore size and a sleeved cylinder. As you piston grows in over sizes you NEED to have the head opened up at some point to properly clear the piston or you can crush the ring lands. A sleeved cyli deer will have had the topof the cylinder trued to set the sleeve the same height as the casting. If there were imperfections it could have had a lot taken off usually a few thousandths is all you need but a bad cylinder ;can require much more.
Be sure to check the head.
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No grinder? :'(
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Use a Chisel... call it a turbo cut... LOL
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A chisel? Shoot just drip a little acid down there till it works silly. It'll probably be polished too maybe. P*
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I joined QR just because of this post. I gotta know how it all worked out and how this thing runs!
I'm sure it's gotta run on 110 or greater, I'd say she's gonna have plenty of compression. I'm building an 88 motor right now. The faces where the cyl bolt to the case on mine are a little scarred up and I've been gathering info on how much can be cleaned off of each cyl land and what head and port mods must follow. Found a must read for everybody (since it's free) http://www.datafan.com/Horsepower_Blog/gordon-jennings-two-stroke-tuners-handbook/
Check it out! Loads of info. It's got slot of the formulas. Also I have an LT manual here if y'all want me to look anything up.
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What's the scoop on this build? Any progress?
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some lol i had a spacer plate made fix that issue almost done had some water pump issues all new stuff still leak got a new impella and it stoped leaking which i dont no how but it fixed it
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I'm ignorant. Why did he have to make a spacer? Why couldn't an alternative solution be had? Is his Jug decked?
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His piston was sticky out of the top of the cylinder ALOT when it was put together.
We are speculating that "someone" aggressively cut the deck too much. So he had a space plate that would be placed at the base to raise the cylinder back up to spec.
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Now on mine I had .40 off the bottom and .20 off the deck. But I run thicker afm gasket to fix mine .I think the gasket is .40 .when I had my head cut fir proper squish I had to use a gasket because of a defect in the cylinder.