06 crf250x wheel on my 01 cr250
By Kaito Sutton
Hey guys, so cant find much online about cr 250r enduro conversions (nothing recent) so im wondering if it is an option or not. I currently have a crf 250x 2009 and a XR 650r. If i want a 2 stroke enduro but want to stick with the honda line up, is a 2007 or 2005 honda cr 250r a good option. and if so what would need to be done to it to get it up to spec for trail and enduro riding. Thanks very much
Note: This specifically applies to the '92 - '01 CR250 engine, but it should be adaptable to any 2-stroke. The basic idea is to pull the carb and exhaust, plug one and pressurize the engine through the other to look for leaks.
It's very important to pressure test a 2-stroke after it's assembled. The reason is that a 2-stroke gets it's lube through the pre-mix. An air leak means your engine can run lean. Lean means too little fuel. Too little fuel means too little lube. Too little lube means death to your engine. So here we go.
First, you need to pull the seat, tank, shock, carb and pipe. Everything you need (other than a tire pump) is shown below.
The assembly below is basically a 1-3/4" PVC plug (same OD as the intake pipe ID) that is transitioned down to a 0-15 psi gauge, a shut-off valve and a Schrader valve (to connect a tire pump). The 1-3/4" PVC plug is a tight fit in the intake pipe, but it'll fit with enough persuasion. I used yellow heavy duty pipe tape (made for gas systems) to put everything together. I don't have all the technical names for everything, but if you take the pictures to a hardware store, they should be able to help you piece it together.
The item below is an adjustable rubber freeze plug. They are available at automotive parts stores in various sizes, but the closest one I could make work was a 1-3/4" version. You tighten the nut which squeezes two metal plates together which squeezes and expands the rubber piece between the plates. You have to tighten it a lot, but it makes a good seal in the exhaust port.
Before you install everything, make sure that the piston is at BDC (so that all the ports are open), the spark plug is installed and all other components are properly tightened. Below, you can see the gauge/valve assembly installed in the intake pipe. Make sure to tighten your intake pipe hose clamp tightly as the pressure will tend to push the assembly out.
Below, you can see the freeze plug installed in the exhaust port.
Once you have everything installed as shown, use a tire pump to pressurize the engine to 6 - 8 psi, then close the valve and watch the gauge for any pressure drop over a 5 - 10 minute period. A well sealed engine will hold pressure with no observable pressure drop for 10 minutes easily.
One common "leak" in a healthy '92 - '01 CR250 engine (and probably other types) is through the powervalve linkage. It probably doesn't affect performance, but it'll sure throw your leak measurements off. To avoid leaks, make sure the powervalve linkage is correctly lubed (per the Service Manual) with grease and Moly 60 Paste during assembly.
If your engine holds pressure with no observable drop for 10 minutes, you're good to go. If the pressure drops 2 - 3 psi or more over 10 minutes, spray soapy water all around the pressure test parts first to check for leaks there. If you find none on the test setup, start spraying the soapy water around the base gasket, head gasket, center gasket etc. Any pressure drop of less than 2 psi over 10 minutes is your call, but I'd definitely fix it.
I've had really good results by using Permatex Copper Gasket Sealant on the base gasket, PV cover gasket and reed cage gasket. I don't use anything on the head gasket.
What value would you say a 1986 cr250 with a freshly plated cylinder and new top end, newer tires, newer chain & sprockets, in overall very good condition?
I picked up the bike (cheap) a month or so ago in need of cylinder replating & top end. Apparently the headgasket blew internally scouring the cylinder. The crank feels good and the bike is very clean/good condition.
I havent put the bike together yet (too busy to ship cylinder and order parts), but figure I would have a total of $600 (including bike cost) to get it into good running cond.
A friend wants to buy it as-is for his 15 yr old 200# kid. What value wouldyou put on it in As-is condition vs with a fresh engine?
Okay so I've been writing this story and been posting it on a different forum, but I wanted to see how TT likes it.
Mark grimaced as his CR85s wheels touched the ground on the finish line jump at Goldendale raceway in Goldendale Californa.
"And Mark peterson finishes fourth" Mark heard the anouncer say. Mark came to a stop in front of his Dad and Brother, where he handed his bike off to his dad.
" I cant belive that scumb bag Chris Marvo won again!" Mark said angrily. Mark had been in first for the first 4 laps in the the 80A class but on the last lap, 3 corners the finish line,Chris Marvo had tried to pass him and his back wheel hit Marks front wheel, making him fall. Mark had scrambled to his feet and got his bike started again and finished 4th.
"I know" Marks brother Tim said "He is such a jerk, If hes gonna pass, he needs to stay farther away, not come in and hug you"
"Well you ran a good race son" Mr.peterson said " Nextime I'm sure you'll do better." Marks dad had raced when he was younger, but now he was just a pit board hoalder/ Mechanic for his three Motocross racing sons. "We better get your bike back to the trailer"
They walked to their enclosed trailer and put marks bike on a stand.
"Nice race honey, are you okay from that fall you took?" Mrs peterson asked.
"I'm fine mom" Mark said "It wasn't even a hard fall." Mark and Tim walked to the stands to watch their younger brother, Carson, In the Final moto of 65B.
Twenty Minutes later Mark pushed his little brothers bike back to the pits. Carson had finished third. Marks mom was hugging carson since it was the best finish he had ever had. The kids loaded thir bikes into the trailer and then got in the backseat of the truck.
The ride home was about 4 hours so By the time they got home it was 8:30 so Mrs.peterson put carson to bed while Mark and Tim took a shower. At 10:00 Mark went to bed not wanting to go to school the next day.
"How'd the race go yesterday?" Asked Marks best friend Nick when he got to school the next morning
"Crummy" Mark said.
"what happened?" Nick said. Mark told Nick all about Chris Marvo hitting him.
"What an idiot" Nick said
"You're tellin me"
Marks first few classes went by fairly fast. At lunch several peopl who had been at goldendale raceway told mark nice job at the race. Marks school was filled with kids who rode and raced dirtbikes. All the MX kids sat by each other at lunch. Together there were around 30 kids who rode in the 7th grade.
"Hey Mark, are you doing the race at Chadale MX park this weekend? A boy named Kenny asked "Its their first race of the year"
"Yeah, I think I probably will" Mark said " I bet Chris Marvo will be there. Then I can beat him"
Sure enough as the weekend rolled around Mark saw Chris Marvo walking the the track with his dad saturday morning before the races.
"I'm gonna beat that punk today" Mark said as he lifted his bike onto a stand.
"Just race smart and you'll finish on the podium" Marks dad told him. Mark and his brothers all walked the track, looking at the changes the tracks had made since last year. Then they headed off to the riders meeting. The race organizer talked about the practice order and all that stuff.
Marks qualifier was the fourth race of the morning. He pushed his bike to behind the gates. All the riders in heat number1 of 85A drew out of a hat to see what gate they were in. Mark drew a peice of paper with a Number 6 on it. He counted out to the sixth gate and pushed his bike to the gate.
"Good luck" A boy next to Mark said. Mark looked at him and realized it was Drake Thomas, A very fast rider who Mark had never raced against since he raced 85B They year before.
"Good luck to you too" Mark said.
The race Before 85A had ended and the card holder was pointing at everyone to see if they were ready. Mark got his head over the handle bars. The card was up. the card was sideways! The gate dropped. Mark pinned the throttle, leaning forward. He was infront but out of nowhere someone got in front of him. It was drake. They came around the first turn. Drake had gottten the holeshot, mark was in second.
Mark was still in second as he came across the finish line jump. It was just the qualifier to get into the main so mark had not tried to pass drake.
Half an hour later Mark was sitting under there awning changing his air filter when Chris Marvo walked up to Mark.
"Hey looser, I see you made it to the Main" Chris said through his yellow teeth "I guess that means Im gonna have to whip your butt in the race again"
Mark felt anger in side of him but couldn't think of a comback, so he just continued putting the air filter in.
"Get lost Chris" Tim said as he walked up.
Mark was getting butterflies in his stomache as The 30 second card turned sideways and the gate dropped. Mark hit the gas. He saw chris come around the first corner. Chris got the holeshot but Mark was on his tail. Mark remained in second behind chris until the 4th lap where he saw a perfect chance to cut him off and take the lead.
Mark pinned it and cut off chris! He was in the lead. Just one more lap! He kept going in first for the next lap. A few corners before the finish line chris tried to pass Mark for the lead but didn't suceed. Mark felt Chris on his tail. He looked ahead to the next jump. It was a big tripple into a corner. No one in the 85A Class had Trippled it yet, they just doubled it, but Mark had to if he wanted to win. he increased his speed a little! He hit the jump. The ground looked along way away from where Mark was. He came down on the landing and Hit the breaks to slow down for the corner. He looked ahead and there it was. The finish line jump.
Mark did small whip across the finishline jump.
Mark High fived his brother and his dad. They expected him to go say something to Chris but he just gave his bike to his dad ad started walking towards the pits.
After he got his gear off he sat down in a chair under the awning.
"Nice race Mark" Mark loooked to see who had said it and saw a fairly short man with brown hair.
"Thanks" Mark said not knowing the man
"My name is Jordan Styner, Manager of TPA Racing team." Jordan said
"Nice to meet you Mr.Styner" Mark said politely.
"Call Me jordan" Jordan said "That was a very nice race you rode out there. I think you should consider joining The TPA racing team as our 85 Rider."
Mark stared at Jordan Styner. Mark had a few sponsors but none as big as a racing team.
"Are you serious?" Mark asked amazed.
"Dead serious" Jordan said grinning."What do you say?"
" Uhh, Im gonna have to talk it over with my dad" Said Mark still staring at jordan.
"Call me" said jordan handing Him a card.
Okay That was chapter 1 guys. tell me what you think