Lost builder

[tlr7272]

I AM DOING A TOTAL BUILD ON AN 86 250R .... MY INTENTION IS TO BUILD A 50 hp plus woods quad..... I have boughy many of them but this is WAY different I just purchased an 86 cylinder that has been mx ported and polished and I have a 38 mm airstryker carb with v-force 3 reeds... so with that said am I even in the right direction??? what should I do to bottom end long rod short rod stroker IDK? it has to be reliable SO COULD SOMEONE PLEASE DIRECT ME THE RIGHT WAY!!!! and since im going to b in the bottom anyway should I put a better clutch in it??? aAlso the dome should I put a cool head on it or what should I use.....? what about the electronics ?    thank you to anyone who helps cause im trying to get the motor wrapped up so I can move onto shocks,a-arms ,steering stem axle , sprockets the list goes on.....  thank u

[Tbone07]

We have all told you our opinions on this. You should look ath the previous threads that you have created. All the answers are in there.

[tlr7272]

that's impossible I just purchased cylinder?/ but that's okay il FIND OUT SOMEWAY!!  BUT THANK YOU GLAD U SET

[Tbone07]

If you purchases a cylinder that was already ported, you have to use a crank that it was setup for. You can't simply use a +4mm crank

Find out what crank the cylinder was originally used for.....was it a spacer plate cylinder?

[Hawaiiysr]

:carlos::carlos::carlos:

[Jerry Hall]

I AM DOING A TOTAL BUILD ON AN 86 250R .... MY INTENTION IS TO BUILD A 50 hp plus woods quad..... I have boughy many of them but this is WAY different I just purchased an 86 cylinder that has been mx ported and polished and I have a 38 mm airstryker carb with v-force 3 reeds... so with that said am I even in the right direction??? what should I do to bottom end long rod short rod stroker IDK? it has to be reliable SO COULD SOMEONE PLEASE DIRECT ME THE RIGHT WAY!!!! and since im going to b in the bottom anyway should I put a better clutch in it??? aAlso the dome should I put a cool head on it or what should I use.....? what about the electronics ?    thank you to anyone who helps cause im trying to get the motor wrapped up so I can move onto shocks,a-arms ,steering stem axle , sprockets the list goes on.....  thank u

You are going to need and engine/displacement much larger than what you can make from an OEM 86 cylinder to get 50 hp plus (on my dyno).  A 50 plus hp  250 is not going to be a woods quads nor will it use that small of a carburetor, nor is it going to be reliable and be easy to tune and run on pump gas.  

I think that you need to lower your hp goals to around 40 hp to meet your reliability expectations with the components you have on hand or you are going to need get the check book out and start over.

[Pumashine]

Well said Jerry. Over expectation runs very high with our new members/builders

[tlr7272]

ok that is very helpful so I should ask guy what it vame off?   thank u    VERY MUCH

[tlr7272]

so do u think I got screwed on 86 cylinder that's been sent to esr for mx port, I paid 150 hes said he was running v force 2 and 39mm carb and he had 50 plus horses mayb cr ign tooo IDK......what do u think is it realistic

[tlr7272]

its cool I got check booook and I could go buy a 20,000 quad for 6to7 all day im just passing time and I guess it will b trial and error ...not a life ender.... but thanks for imput all of it goes somewhere

[tlr7272]

its all about something different 40 hp 450s are a dime a dozen and actuyally boring but im sure I will come across the right setup to beat a 450 threw the woods or track ...   im positive of that

[broken1]

so do u think I got screwed on 86 cylinder that's been sent to esr for mx port, I paid 150 hes said he was running v force 2 and 39mm carb and he had 50 plus horses mayb cr ign tooo IDK......what do u think is it realistic

He was blowing smoke up your arse when he claimed it made 50hp with that combo. OEM cylinders can be made to run very well but the only way you can get strong bottom end grunt & screaming top end performance is with a big bore. With an OEM small bore cylinder you'll generally get one or the other.

[Jerry Hall]

so do u think I got screwed on 86 cylinder that's been sent to esr for mx port, I paid 150 hes said he was running v force 2 and 39mm carb and he had 50 plus horses mayb cr ign tooo IDK......what do u think is it realistic

Building a 250cc engine package around 55 hp (not a big bore in an OEM casting) is easily attainable when the engine is put into the hands of certain builders, but it is not going to be a good woods bike. These engines can be used effectively on an outdoor MX track in the hands of a small number of pro riders.  

I recommend that my customers replace the pistons in their 50 to 55 hp 250s used for mx at least every 5 hours or less.  These engines will start showing a power decline at about 2 to 3 hours of hard riding without being on the verge of catastrophic failure.

Shifter karts with 250s making well over 60 hp will start showing a power decline at around 1 1/2 hours of hard usage and need pistons every 2 to 3 hours.

The definition of realistic or practical is totally different for different engine owners.  Guys that are running 70 hp 250s in their micro-sprints cars spend the money to replace the necessary parts on a weekly basis if they are highly competitive.  The expense to maintain engines of this caliber is realistic and necessary for some guys but not practical or affordable for the average recreational rider trying to use an engine of this caliber for a weekend of recreational riding.

[All250R]

It's difficult enough to find a builder who will take the time to do a thorough, detailed job and make a reliable engine to order with solid recreational performance.

Finding one who will make the power you're talking about without scamming you requires a select qualified builder, likely who has worked with professional racers and packs a database of years worth of precision technical findings on precision instruments. I am not in the later camp, but the more challenging things to me about providing honest engine design services was helping people not underestimate what it takes to build to what expectation and how that effects their budget.

Jerry is in this later camp. Most people who will encounter him online in a forum will not grasp how much difference there is between what that type of builder understands from most other builders.

[udontknowme]

what you have working against you is the non-variable exh port. without this feature your stuck between a rock and a hard place. from my experience working with nonpowervalve stuff is your always going to be making a compromise how well the engine performs in a desired rpm range