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mt2 compression problem

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Old 01-22-2004, 08:00 PM
  #1  
itrunshot
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Default mt2 compression problem

Well, yesterday i hit a bump going about 30 and started flipping. I had to pull some grass out of the air filter but other than that everything seemed fine. After that the engine wouldnt run unless i was giving it gas and would die frequently. After stalling 4 times it got to where it was almost impossible to start. I noticed the pullstart seemed to have less resistance than before. I couldnt even prime the engine. I had to yank on the pullstart repeatedly to get it to prime. I took it apart today and pulled the carb off and made sure all the lines were clear. I couldnt find anything that looked wrong, although i had no idea what to look for, so i put it back together. I pull the pullstart and now it feels like the compression is back. Now it would prime with only 2 slow pulls opposed to 10 fast pulls.

So i take it outside, put my ignitor on and try to start it and now the compression is low again, and wont even prime. I dont know what to do, im getting frustrated, I've only had about 4 hours of good driving time in the month ive had it. Someone please help me out.
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Old 01-22-2004, 08:31 PM
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Default RE: mt2 compression problem

Check your carb and head for leaks. Also go over the engine block and look very carefully for cracks. I was having similar problems with my engine and it turned out that the carb was leaking air due to some modifications by the previous owner. Also, have you tried changing your tune a little bit? It could just be a mix problem. I would also make sure that your piston sleeve doesn't look scored at all. And if all else fails call Cen. They could give you some other ideas or they may want to take a look at your engine.
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Old 01-23-2004, 05:28 AM
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Default RE: mt2 compression problem

i reckon u ought to fetch a rebuild kit its only 32 bucks for a piston and sleeve and backplate gasket at www.toyhaus.com(bought mine there) and that ought to get urs running again but u will have to rebreakin

if grass was caught in the filter dirt got in and killed the sleeve's pinch zone that gives it half of its compression
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Old 01-23-2004, 09:56 AM
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Default RE: mt2 compression problem

I just dont understand why it had compression again after i took it apart and then put it back together. I dont have the money to replace parts unless thats for sure whats wrong with it. How can i tell for sure?
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Old 01-23-2004, 11:02 AM
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Default RE: mt2 compression problem

I agree iw 378, if there is any dirt or grit in the engine your piston is toast. Take your engine apart and see if there is any dirt in the bottom of the crank. Also look for scoring in the sleeve or on the sides of the piston.

Like I said though, look for air leaks as well. That was a really big problem for me.
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Old 01-23-2004, 11:07 AM
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Default RE: mt2 compression problem

Did you reoil the engine when you put it back together? The oil help seal the scratch inside the combustion chamber & the engine felt OK with oil. Once you put fuel in, the oil quickly dissolve away! Just a guess!

Take the engine apart & run your finger nail around the cylinder & the piston to see if anything catches. If so, then I am afraid it is going to be a rebuild job. Good luck.

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Old 01-23-2004, 12:57 PM
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Default RE: mt2 compression problem

Ok, i got the piston and sleeve out. The edges on the top of the piston seem very rough. I can feel a couple scratches on the sides of the piston. I dont feel any scratches in the sleeve. Is this enough to cause the low compression? Should i go ahead and spend the money on a rebuild? thanks for the help, I'm new and dont know much about these.
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Old 01-23-2004, 02:08 PM
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Default RE: mt2 compression problem

If there are scratches, it will most likely affect compression. The easiest way to fix the problem is with a rebuild. You may want to talk to Cen anyway, and see if there are other alternatives.
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Old 01-23-2004, 03:23 PM
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Default RE: mt2 compression problem

Well....looks like I screwed up my engine too. It was my fault....not CEN. [:'(][:'(] So, does anybody have any suggestions for a replacement engine? I really like the stock .16, it kicks *****, but is there anything else out there (within reason) that runs really well in the MT2? That is, without modifications??

thanks........


I know I could do a rebuild....but before I do that just looking for easily put in replacement options (wouldn't hurt to have a back-up anyways )
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Old 01-23-2004, 04:28 PM
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Default RE: mt2 compression problem

You can run a .21 with [link=http://www.neweramodels.com/cgi-bin/item.cgi?session_id=mbpomquyofkdoiayoncspsihpfcoji ig&part_id=1816]this[/link] kit. I think you can fit a .18 in without any mods, but don't quote me on that. Of course you could always go with a high HP .15 racing engine. Or just buy a second .16 from Cen, they are pretty cheap.
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Old 01-23-2004, 04:47 PM
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Default RE: mt2 compression problem

Well, I just ordered a piston and sleeve. How should i go about cleaning the inside of the engine?
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Old 01-23-2004, 05:16 PM
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Default RE: mt2 compression problem

Once you have everything taken apart, you can actually flush it all out with water. Make sure that everything is really clean, check your bearings to make sure they are clean and still good and then spray it all down with WD40 to get rid of the water. Then coat everything with after run oil as your putting it all back together.
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Old 01-23-2004, 05:38 PM
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Default RE: mt2 compression problem

get a new backplate gasket if u dont want to chase an air leak they are fiber and really thin i will be rebuilding soon from an overheat even tho the engine has restored its compression on its own to 100% of what it was the day it overheated

rebuild kit $30
new engine(epic .18 1.8hp)$140
getting ur thumb stuck in a tiny cylinder bore $priceless
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Old 01-23-2004, 08:36 PM
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Default RE: mt2 compression problem

I have a big block in my cen. If anyone needs my .16 engine I'll sell/trade it.
it is perfect. heatcycle break in with mounts and exh and 2 aircleaners.
maybe 1 1/2 gallons of blue thunder sport.
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Old 01-23-2004, 08:37 PM
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what is the price u want id love a spare NT-16
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Old 01-23-2004, 09:12 PM
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Default RE: mt2 compression problem

I never really thought about it till this post.
I have the engine-full exh-complete clutch- and a brand new CEN performace chutch shoes.- plus 2 air cleaners=new muffler mount.
make me an offer. all parts new cost 212.00 is half fair?

http://mivasecure.abac.com/toyhaus/m...vc?Screen=BASK

it has like new pinch, never been apart, and AR oil used (most of the time)
Oh you can have the motor mounts and bolts too.
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Old 01-23-2004, 11:40 PM
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Default RE: mt2 compression problem

ok....i feel stupid and HAPPY all at once!! My father-in-law came over today and looked at my MT2. I told him the problems and he asked me if I had the cooling head on tight............... That is why I was getting no compression. The SOB starts on the first pull now. I feel quite stupid.....

CEN ROCKS!!!!!!!![:@][:@][:@]
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Old 01-23-2004, 11:54 PM
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Default RE: mt2 compression problem

did u use a x pattern
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Old 01-24-2004, 12:31 AM
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Default RE: mt2 compression problem

Glad to see you got your truck running again smokinjoe. And didn't I say to look for air leaks?
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Old 01-26-2004, 06:00 AM
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Hello Auto2,

Long Time no see!

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Old 01-26-2004, 06:03 AM
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ORIGINAL: 378

did u use a x pattern
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Old 01-26-2004, 06:09 AM
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Default RE: mt2 compression problem

ORIGINAL: auto2

I never really thought about it till this post.
I have the engine-full exh-complete clutch- and a brand new CEN performace chutch shoes.- plus 2 air cleaners=new muffler mount.
make me an offer. all parts new cost 212.00 is half fair?

http://mivasecure.abac.com/toyhaus/m...vc?Screen=BASK

it has like new pinch, never been apart, and AR oil used (most of the time)
Oh you can have the motor mounts and bolts too.


that looks familar i have that dynamite filter too my old boot broke because someone insisted that zip ties($2.50 for 500) were too pricey and i had to use a metal clamp which cut the boot engine still runs u seem to have more cyl head scratches than i do all my rolls were in grass with no body the body on rolls were on pavement(lol)
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Old 01-26-2004, 06:55 PM
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Default RE: mt2 compression problem

Ok, i cleaned out the motor and carb, and put in the new piston and sleeve today. I took it out to break it in and it wouldnt prime. I had to blow into the fuel hose that goes to the exhaust to make it prime. i got it to start but there is no smoke or fuel coming out the the exhaust. I am at factory settings. Someone please tell me what i could have done wrong.
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Old 01-26-2004, 06:58 PM
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Default RE: mt2 compression problem

did u get a new fiber backplate gasket i see another post by me saying to replace that if u dont wanna chase a air leak and thats why u aint getting it to smoke the backplate is leaking and the normally overrich factory settings are lean get a new backplate gasket
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Old 01-26-2004, 07:27 PM
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ORIGINAL: 378

did u get a new fiber backplate gasket i see another post by me saying to replace that if u dont wanna chase a air leak and thats why u aint getting it to smoke the backplate is leaking and the normally overrich factory settings are lean get a new backplate gasket

I did get a new backplate gasket. There is compression, but its not drawing fuel.
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