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.

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.

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

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?

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.

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.

Normanski
Bought a MTA-4 but have No time to run it!

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.

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.

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 :D)

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.

RE: mt2 compression problem
 

Well, I just ordered a piston and sleeve. How should i go about cleaning the inside of the engine?

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.

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

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.

RE: mt2 compression problem
 

what is the price u want id love a spare NT-16

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.

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...............:eek: That is why I was getting no compression. The SOB starts on the first pull now. I feel quite stupid.....

CEN ROCKS!!!!!!!![:@][:@][:@]

RE: mt2 compression problem
 

did u use a x pattern

RE: mt2 compression problem
 

Glad to see you got your truck running again smokinjoe. And didn't I say to look for air leaks? :D

RE: mt2 compression problem
 

Hello Auto2,

Long Time no see!

Normanski

RE: mt2 compression problem
 

RE: mt2 compression problem
 

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)

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.

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;)

RE: mt2 compression problem
 

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

RE: mt2 compression problem
 

Just because no fuel is dripping out of the pipe dosn't mean it is not rich enough. Just having that means it is running great for a breakin procedure. And once again, it dosnt have to drip.

I broke mine in somewhat lean and it is still getting more powerfull as I use it.

RE: mt2 compression problem
 

richen the mixture until it stalls, then lean it out an eighth of a turn. that way you know you are running rich enough. As far as it not sucking fuel, does it suck when its running? if so, it may have just had trouble priming the line.

RE: mt2 compression problem
 

the best way ive found to prime mine is fill the tank hold the lid up and press on the pressure line where it goes in the tank pull the lid back till it dont want to move and let it slam that will try to compress the fuel but the fuel will run up the line to the carb instead it uses the path of least resistance

RE: mt2 compression problem
 

I found an air leak but i dont know how to fix it. It's leaking aroudn the shaft that comes through the middle of the backplate and into the pull start assembly. Why would this have a leak?

RE: mt2 compression problem
 

After looking at things a little more it seems like that wasnt where the leak was. I think its leaking around the head. The head is on tight and yes i used an x pattern, the glow plug couldnt get any tighter, is it possible that the head just isnt getting a good seal after being flipped with no body? This looks like a good excuse to get a better head, but if i do that and still have problems ill probably torch it.

RE: mt2 compression problem
 

3 fixes
[ul][*] rtv around the pullstart housing[*] new backplate the bushing therein is shot[*] a few well placed strips o duct tape as a temporary fix untill u can do the second option but not as permanent as the rtv
[/ul]

RE: mt2 compression problem
 

When you took the head off, did you make sure that the head gasket was there? The head gasket is very thin metal and you may not have gotten that back in place. without a head gasket, the head will not get a good seal and it will leak. You may be able to get a head gasket at your LHS. If not, you can get one from www.ehobbies.com

RE: mt2 compression problem
 

I just took it out, and it will run somewhat. If i run it very rich and keep the rpms up it will run, but the head gets hot quick. It seems like its doing what it was doing the first time after i wrecked. Its only running if im giving it some throttle, how much you think a hobby shop would charge to fix it?

RE: mt2 compression problem
 

replace the backplate to replace the bushing set it at breakin and go from there

RE: mt2 compression problem
 

just take your head in and see if they have a gasket that will fit it. It sounds like you are fighting an air leak. I had the same problems when I bought my truck (used). I was missing the head gasket and the carb was leaking air around the base. You could seal up the exhaust on your engine and use some low pressure air blowing in the carb with the piston at the bottom of the stroke. Use WD-40 on all the joints in the engine where you suspect a leak and see if you get air bubbles. Then you will know if you have a leak and where its at.

RE: mt2 compression problem
 

Well you said it your self. "I know where the leak is but I dont know how to fix it." That to me sounds like you dont know that much about it and if I were you, i would stop screwing with it and stop risking any more errors and send it to CEN.
They will know what to do and probably for free.

RE: mt2 compression problem
 

Tony, if he knows where the leak is, its just a matter figuring out what is causing the leak. Usually its a missing gasket or loose bolts. In this case I am thinking its a missing head gasket. Most people don't even know there is a head gasket on a nitro engine.

RE: mt2 compression problem
 

he said the backplate is leaking where the start shaft sticks out i think the bushing there is shot and a new backplate will fix her up it wouldnt hurt to try that and a new backplate gasket

RE: mt2 compression problem
 

Exactly. I understand that he wants to learn off his mistakes but that is what reading is for. Dosnt it make more sence to read on what you are doing instead of just winging it?If you dont want to further damage, I would call CEN. And If you dont what them to fix it, at least ask if there are any other possable problems.

RE: mt2 compression problem
 

BTW, I have not had time to read this whole forum. Where exactly is the leak?