Forkin A.... That one ferret on steroids had that one wolf by nose & wasn't wagging his tail then!

How much does a new motor run for? Like an 87' model? I heard they were the fastest year, but also the hardest year to get parts for. What to do. Lol

Why couldn't he just bolt an 87+ cylinder to his 85-86 bottom end?

Ok, first off the 85-86 bottom end won't accept the 87+ cylinders because they are fundamentally different engines.
One has reeds in the case, the other has reeds on the cylinder itself, and that's just scratching the surface of the differences.

As for installing an 87+ engine in an 85-86 frame, it's well within the abilities of an average mechanic.
It's considerably easier than building a hybrid, though the modifications for a hybrid will also allow a 250 engine to be installed with the addition of a 1" spacer.
So if one were to do the hybrid mods to a 250, you could essentially run the 250 indefinitely until you found a great deal on a 500 engine to simply drop in without needing frame modifications.
The most that would be required for a simple 87+ upgrade would be modification of the front engine mounts and downtube.
Replace that single downtube with a 87+ wishbone, or two tubes on either side, would be all that's required, other than carb setup, new pipe, and maybe the CDI.
It's actually very easy work and could be done by pretty much anyone with access to a welder and some way to notch tubing.

There's rarely a situation where you can find "theeeeee best" pipe for a certain engine, as different people like different things.
However, when there's very little competition in the pipe department, sometimes you get a pipe that is so much better than all the other pipes out there that you can declare a clear winner.

For the 85-86, FMF is the best pipe commercially available (ie not a custom pipe).
For an 87+ 250, Matt's is THE pipe to have, not even a custom pipe will get you close without a LOT of R&D.
For the 500's, Jerry Hall makes a great pipe, followed by the Q pipe and AAEN, and Mitch's DCS pipe is starting to look pretty good too.

Sorry westtex did I forget to mention I know absolutely zero about lt250's?

Sorry westtex did I forget to mention I know absolutely zero about lt250's?

That's what forums are for, we learn from each other

does it clear out after a few seconds of full throttle? jetting may be off I think my wifes 250 has a 180 main in it but its a 90 and has a 34mm not the 32mm carb.

your best bet with the jetting is to start rich and work down slowly till you get the throttle response your looking for. plugs are cheaper than pistons!!! where are you located? There are plenty of guys here that will get you on the right path. Maybe one of the top builders is close to you

What plug should I be using? My quad has a plug with the number 8 in it. My brother told me that I need to run a Plug with a 7 in it.

Would the NGK plug with 7 in it be a step back? My brother told me the smaller the number, the hotter they spark or burn. Currently mixing at 50 to 1, and the plug is fouling when I ride through the woods. I may not be keeping my rims up enough to get a clean burn. What do you think?

1. Your carb tuning is probably way off, which makes a huge difference in power.
It probably should be spinning tires in all gears on loose gravel.

2. If your plug keeps fouling out, your carb is definitely not tuned correctly.
You probably don't get into the throttle too much when trail riding, so I'd bet your needle position isn't correct.
Move the needle down into the carb one step at a time (that means put the clip one notch higher on the needle) and see if that fixes your fouling issues.

3. When you're tuning a carb, you want to start off with the lowest circuit and work your way up to the main jet, and you also start off with a clean plug.
Start the bike up and let it idle for a while, occasionally blip the throttle, but try to keep it at idle speed.
Shut it down and check the plug...if it's black you need to tune the idle (pilot) circuit.
Turn the pilot air screw all the way in until it stops, then back it out 2.5 turns.
Clean your plug (use a sandblaster if you don't have a plug cleaner) and re-install.
Start it up and see how it runs, check the plug.
If it's still black and fouled up, you need to go to a smaller pilot jet and try again.
There's a lot more to it than that, but it'll get you started.
Next, you'll want to test out the needle jet.
Use the same procedures as before, except don't run it past 3/4 throttle (if you can find a way to limit the throttle to that point, even better).
Check your plug visually and see if there's any soot or fouling.
If there is, you're rich on the needle.
Adjust the needle until the soot goes away and you're left with a brown color.
Now you're ready to test the main jet, and the procedure is a bit different.
Find a spot where you can run full throttle for an extended period of time (at least 10 seconds, but more is good too).
You'll need a new plug for this part (2 plugs at least).
Start the quad, get it warmed up by driving it around, then shut it down and put in the new plug.
Keep your old plug on hand.
Start it up and immediately get on the throttle and do your run.
Using the kill switch, shut it down without letting it idle, clutch it and make the engine stop right then and there.
Remove plug, replace with old one, drive back home.
Cut the threads off the plug all the way down to the base and look at the insulator (this is called a plug chop).
There should be a small ring of discoloration just above the base about a mm or two thick.
That's where the main jet leaves an indication of how the engine is running at full throttle.
Light to no color or white - LEAN (go up at least 2 sizes for piston safety)
Brown/chocolate color - PERFECT
Black/sooty - RICH (drop a size on the main and try again)

Now, if you have good eyes you can eliminate the physical plug chop by looking all the way down at the base of the insulator, but it's not recommended until you get some experience doing it.
You'll be buying lots of spark plugs if your main jet is off...so get the cheap ones (BR8ES, unless you have a resistor spark plug cap, then get a B8ES).
Later on, when you get the hang of reading plugs without cutting threads off, you can take a plug reading, clean it on a plug cleaner/sandblaster, and re-use it for tuning.

There's a lot more to tuning than that, but it's the basics.
Somewhere on the forum there's a big writeup on jetting, read up.
This also only takes into account that the rest of the engine is in good shape and it's only the carb giving you problems.
You could have all sorts of issues causing a loss of power...
-compression
-reeds
-air filter
-ignition/timing problems
-detonation/fuel quality
-intermittent fuel flow issues

Some are identifiable by how they act, some just affect the entire operation of the engine, some are hard to troubleshoot.
Start with the carb tuning and work your way from there.

Oh hell.... I foresee a Trinity blasting in the near future.. You're better off just getting yours straightened out, than trying to reverse the damages done by Trinity.

Tex is right. You need to know or have someone that knows how to tune your quad.
The first time you tune it after it's built can be a bear but once you get it done then it's a matter adjusting. you know you have it down when you can go the whole season on one plug.