250R help

[Jimmah]

I need help finding out what yr motor is on my 87 R, the guy told me it was all an 87 but for some reason im doubting that now. I just had a new top end done and the new piston hits the dome.

[4punksdad]

take it back to the guy who rebuilt it for you.

u amy have an 86 piston.The wrist pin in the 86's are lower than the rest of the years.So it will make your piston go up farther.And it will hit your dome.U can either get an 87-89 piston or get a spacer plate.

I bet that is what happened.


IM me next time we are both on.



86 trx250r
97 300ex

if you haven't put the cylinder back on yet you can find the year on the bottom of the cylinder stamped into the sleeve. or just call honda and give them the motor number

[beerock]

sounds like a 86 piston, if you dont want to buy a new piston, go buy a SPACER PLATE!

then it should run.

I hope you didnt screw anything up to bad......

[QuadRacer041]

do you know what bore the cylinder is on???that makes a big differnce,when did you hear it hit, when you started it or when you just cracked it over???
before you go taking too much apart remove the head and the head gasket, since the old gasket is garbage now try this:
take a razor blade and trim the head gasket so the opening for the piston is bigger, lay the gasket on the cyl. and see how much smaller the opening is than on the cyl. and trim it out. put it back on with the head and just snug down the head bolts, take out the plug and cranck it over by hand and see if it hits, you should be ok, if it is get a new head gasket, trim it, and put it back together. what your problem might be is as you bore your cyl bigger and bigger the piston gets bigger then the head gasket opening and hits that not the done.
if after you trim your old gasket and it still hits then i would say that you probably have the wrong piston and rod combo.'86 needs to stay with '86,'87-'89 are interchangable.
hope you get it fixed soon weather is starting to get nice out there.



Lou

[Jimmah]

Well I'm not exactly sure whats wrong I had enough of it yesterday. What I can tell you is it's .020 ( or .20 however u right it, its 20 over stock) and with the dome on it will not kick, the kicker will not move and if I try and turn the engine witht he flywheel I think it, whats evers under the leftside engine case, if
I spin it with a wrench it will spin 3/4 of the way around in both directions. Would 20 over hit the gasket?

[QuadRacer041]

no .20 over should NOT hit the gasket,
do you remember what the piston looked like?
did the bottom of the piston look kinda the same on both sides or did one side have kinda like a U cut in it?
if yes its an '86 piston, if both ends looked similar then its an '87-'89 piston

[Jimmah]

I believe it had a U, not 100% sure... I will be tearing it apart tomorrow so I'll know soon enough. Cross your fingers nothing else is messed up for me.

[QuadRacer041]

well if its a U then you have the wrong piston in it if its an '87.
if you damaged anything let me know me and my buddy's have a bunch of extra parts.

[Jimmah]

:grr well its an 86 piston, K&K sent me the WRONG piston!!!!!!! on the piston box it has the part number for a 86 and on the invoice it has the parts number for a 87. They arent gonna enjoy my phone call tomorrow. piston box

[Jimmah]

invoice

[beerock]

Yo listen to me!

BUy the spacer plate!!!!!

It will increase your crankcase volume and make your powerband delivery smoother and will add a little bit of top end.

DO not take the head off!!!!

You will waste a gasket if you do.

just unbolt the cylinder and buy a new base gasket.(or 2 if you get the spacer)

Make sure the piston and wrist pin bearing arent damaged.

If they are tell them they gave you the wrong year piston and it hit, and now you want a new one. but since someone told you about a trick setup that you want to use a 86 piston again. but you want to order the spacer plate.

if you dont feel like doing that then just get the 87-89 piston.

alot of pros use this setup.

I just wanna know if you tried moving the kick starter with your hand before you decided to kick it?

You could have bent your connecting rod:eek:

I hope not:rolleyes:

time to start praying, because I think you tried kicking it over, and that might not be to good.:o

[Jimmah]

I did try kicking it but the way I kick it over is I push the kicker all the way down then I bring it back about 3/4 and kick it from there. So right away when it didnt move I knew something was wrong. and I called the people who bored my engine to find out what could be wrong and he told me to take the case off and try spining it. The thing is obviously K&K messed up here, I just spent 200 on parts with them and I in no means are goin to spend more to fix a problem they caused.

[oynot400]

Gee K&K messing up?!?!? That must be a first! I hate that place, good luck in trying to get them to make it right. They sure would not do anything for me. :grr

[NJ250Rrider]

Yeah me too, I placed my first and last order with K&K last year. I ordered a set of nerfs and they sent me only the left side nerf. Took 3 phone calls and 6 weeks wait to get it right.

[Jimmah]

I'm pretty sure they will make things good with me cause I will cancle payment on the credit card and they will not see their parts back.

[oynot400]

I tried that trick too with the carb I bought from them. They told the credit card that I damaged it beyond repair and they could not sell it or fix it. They even told them that I didn't follow the instructions that came with part. There was no instructions! I can't believe that Master Card fell for that line! :grr
I seems to me that K&K only takes care of the customers that are in driving distance of their store.

[QuadRacer041]

i have ordered from k&k a bunch of times, and havent really had any problems, they have sent me the wrong part before but have taken care of it rather quickly.i do live in new jersey and am kinda close to them there deliverys only take a day to get to me,try to talk to shawn, he is the owner.
i hope everything works out for you

[beerock]

if you didnt kick it over then, call them up and tell them what I said.

if what you said is true

do this.

order 2 base gaskets,longer studs and the spacer plate. it should cost less than 40 bux.
Try to make them pay for shipping because of there mess up.

pop the cylinder off(with the head still on)

if this is too much for you then hassle with them and get a new piston.

I want to ask you something though.

Who bored your cylinder and when they bored it did they ask for your piston before they bored it?

the best way to bore a cylinder is to have the piston on hand.
Pistons vary in size regardless if it says 66.50- which is 20 over.(stock is 66.00mm)

the piston you bought could have been 66.49 or 66.51(they measure the pistons at the bottom of the skirt)

if the piston is 66.49 and your bore cylinder was bored with a .03 gap for a 66.50 piston then in actuality your gap is .04
It also entails a rebuild sooner than expected.It also gives pistons skirts more of a chance to move around and BREAK..(expanding exhaust ports are bad news with too much of a gap)
So was your piston on hand when they bored your cylinder?
I hope so.



On the other hand if your cylinder was bored for a 66.50 piston and the piston is actually 66.51 then the gap which was set for .03 is actually .02 which means the top end will have increased compression, giving more compression than it should. with less of a gap it gives less chance for error
(if something goes wrong, overheating sand riding etc)- you can easily cold seize a engine with tight clearances.

ALWAYS let your motor warm up





When my cylinder was bored I ordered a 67.50mm piston.My machine guy told me he wouldnt bore it unless he had it in hand. I was like just bore it to that. then he told me why(I just explained it)
my piston was actually 67.489mm if it was bored to 67.50 I would have had more of a gap then needed.

[beerock]

bare with me I am editing the post above, I confused the numbers

*edit*
ok its fixed.

[Jimmah]

They tried to get out of it and told me to just order a spacer plate and stuff but that's not what I wanted....... So I just got my new piston today and I am in the middle of installing it. I had my local dealership, Cycle World, do it. They were the only place locally that didn't send out their cylinders to bore. The guy wouldn't touch my cylinder untill I had the piston so he had it on hand when it was bored. Everything seems to be fine in my cylinder except a blown head gasket, but I had K&K send me one of those too. Even though they did mess up, they did clear up their error quick enough.

[QuadRacer041]

hey beerock,
what series do you race in?did you run last year?how did you finish for the year?
im from nj too and want to know were i can race.