Yep its a fmf. What size jets did you end up with. I know the weather and altitude play a role but I'm just curious. I also took my exhaust manifold off and used some rtv silicone. I'm still having trouble with the idol screw needing to be all the way in. Also when I choked it to start once today it reved up pretty high and I had to shut the choke off for it to idol down. I thought it was going to diesel and it was a ice cold start.

Should the idol screw move the slide up and down? When I had the carb off I couldn't notice any movement.

Also, do you have a normal gasket for the exhaust valve as well as that squish round gasket? I put some rev sealent on the head where the studs are and also on the pipe but I ran it right away and blew it out a bit.  I got some threebond I might try and let sit for a few days and dry up.

You are way lean... maybe an air leak?

http://www.suzukiquadracerhq.com/lt250/put-together-a-simple-air-leak-down-tester-for-under-$30/msg33361/#msg33361

Wow that low of a main huh? Did you mean 310, 290...ext?

Well, good and bad news....

Bad news is I found a huge leak while pressure testing right under where the exhaust flange is where the case comes together.  Also a slight leak at the bottom of the cylinder as well.

Good news is that I found the problem and now I can take the proper steps to fix this.

Do you guys think I should try and find a used bottom end and just swap it out?  The one I have has all the paint stripped off and looks kinda cool like that.  I have a friend who runs a shop and will redo the seals with me for 125.00 but I have to buy all the parts and such.  Maybe I should buy the tools and attempt myself?  I guess i'm at a crossroad of what step to take next and would love some advice from you fine folks.

I figured it was a air leak you had. But when rebuilding these motor you dont want cut cost on seal and gaskets.  Stay with oem gasket and seal and orings.  It will cost a little more but will be worth reliability.  I would just go threw and do all the seal.

actually the oem head gasket is pretty good, and the oem base gasket is better than most of the others, i would get the cometic base and a oem head, and seals are very easy to change, you just need a good pic to remove them, and put new ones in. no need to tear motor apart, just a few things need taken off to do this. if you have tools do it your self, no need to have a shop do them.  put a little bit of grease on the seals before you put them in.

actually the oem head gasket is pretty good, and the oem base gasket is better than most of the others, i would get the cometic base and a oem head, and seals are very easy to change, you just need a good pic to remove them, and put new ones in. no need to tear motor apart, just a few things need taken off to do this. if you have tools do it your self, no need to have a shop do them.  put a little bit of grease on the seals before you put them in.

When you say "pic" do you mean picture? No need to tear the motor apart to replace all the seals and gaskets for the top and bottom end?  Please explain.

no a pick to pull seal out, instead of jamming a screw driver in it.


something like these.

http://www.ebay.com/itm/Snap-On-Mini-Pick-set-of-4-/171209192925?pt=Motors_Automotive_Tools&hash=item27dcdcf5dd&vxp=mtr

What tools will I need for splitting the cases?  Just a flywheel puller tool or more?

well sometimes you can split them with out any special tools, but if they are bonded together good you might need a case spliter, dont go jamming a screw driver between the cases, you will damage them and it wont seal where you put screw driver ati would try to put some yamma bond on the case where its leaking first, this way you dont need to split them. just clean area very well, use rubber gloves so the oil from your fingers dont contaminate the area that is leaking.

well what was the problem.

How did you go from asking us how to split cases to rebuilding the bottom and top end in 4 business days? 

Top end I had already had punched out and I put back together and then had this problem here.  I was debating trying to split the cases myself and save the 100.00 I paid my friend to do this, and just buy some tools and such with the money instead.  That is why I was asking questions about it and trying to figure out my options.

Here is how the bottom end and all the bearings and seals/gaskets got done in a single day, not in 4 days. 

I went to my local shop around 11am and they had almost everything that I needed on hand, except one seal which another local bike shop just so happened to have, I made it to the other shop around noon to pick up the last seal I needed and my shopping was done for the day.  From here I took it back to my friends shop and ended up there about 1pm, and he then tore the engine apart like he had done it 100x before.  We did the whole tear down and rebuild (I had the engine out of the quad already) in about 6 hours as I helped clean parts in the solvent tank and watched as he worked his magic. My buddy has worked in a honda dealership and also a harley dealership as a mechanic, so he knows his stuff pretty well and has all the tools.  Nothing crazy really, just having the right tools and know how and you can obviously do a whole rebuild in a single day.  I definitely learned a lot along the way though!