Topics

1

Pumashine 250R Products / Powder coated front motor mounts

« on: November 01, 2017, 02:00:25 PM »

Polishing cannot be done below 32 degrees. So the solid front motor mounts and windowed mounts will be powder coated Cardinal red

2

Duner / Winchester Bay Dunes 2016

« on: January 03, 2016, 04:44:22 PM »

My brother in law just got through radiation for cancer and does not feel up to riding. I went to pick up my sister so we could ring in the new year on the dunes. Sand is soft wet and spectacular. Resembles the grand canyon with pinnacles of sand instead of dunes. Craiglist find Blue 250r

The 408 puma in the sunshine. Cold and sunny Jan 1st

I lil blurry

Hard to find a rutt to drive through



Just a lil blurry. Just trying to beet the cold.

3

Engine and Bottom End / Puma head o-ring size

« on: December 28, 2015, 09:17:44 PM »

Does anyone have sizes for the o-rings for the Puma head. Mine are 2X90-075 for the inner ring and 2 047 N70 for the outer ring. Once we get the correct sizes this will become a sticky for peeps wanting to order them from the o-ring company for a buck or two.

4

Suspension and Chassis / Setting up a charge, refill for shocks

« on: October 09, 2015, 09:47:31 PM »

Does anyone have a simple diagram of how the regulator and fill hose is setup. I know there is a trick to it but need to know where the bleed knob goes. Any links to the question would be appreciated or your setup and how it works.

5

Pumashine 250R Products / 250R motor stand give away contest for that spare motor you are building.

« on: September 19, 2015, 11:10:00 AM »

I was :thinking: there were some lonely 250r motors out there stored as seconds that were in need of a stand too keep them off the floor/table. The leading cause of case failure besides chain derailment it a drain plug smashed into the bottom of the case. So what I was thinking was to have a drawing using a submitted pics of your spare motor in need of a stand. Each motor entered in the contest will be entered into a basket of names with every other participant. Submissions will be gathered until 12 PM Wednesday September 30th. Winners will be announced Thursday October 1st. Only one motor per entry but you can enter as many different motors as you wish.

6

Body and Controls / Seat Nubbins

« on: August 28, 2015, 05:02:46 PM »

Anyone know where to get these rubber pieces that seem to be better than stock. It has A 29 stamped from the mold. The ones in the front are the ones that were on a frame I bought on ebay. Inner hole is 3/8". Stock are in the rear of pic. A while back guys had a part# you could get at the auto parts store. Thanks in advance

7

Carburetor, Intake, and Exhaust / Jetting Guide - TRX250R Keihin Mikuni Carb

« on: February 14, 2015, 11:15:15 AM »

For whatever reason it becomes necessary to re-jet a carburetor, it is without a doubt a nightmare if you do not have a procedure to follow. The following is nothing more than a technique, procedure, steps or whatever you want to call it to help identify and isolate the carburetor circuit involved.

    You can only begin re-jetting your carburetor if the following conditions are met:
    1. Top end is in good condition.
    2. Bottom end is in good condition. Crank seals.
    3. Spark plugs, air filters, reeds and so on.

    If your bike's motor is not mechanically sound, then all the jetting in the world will not help. With all of the above conditions met, you should be able to jet your carburetor following these steps:

    Step 1: DETERMINE THE CORRECT NEEDLE AND OR NEEDLE JET.
    Step 2: DETERMINE THE CORRECT PILOT (slow)JET.
    Step 3: DETERMINE THE CORRECT MAIN JET.
    Step 4: DETERMINE THE CORRECT NEEDLE TAPER AND CUT AWAY.

    Step 1: DETERMINE THE CORRECT NEEDLE AND OR NEEDLE JET.
    Whether or not your carburetor is a MIKUNI or a KEIHIN, it does not matter. This is the most important step in jetting your carburetor--period!
    1. Remove the main jet.
    2. Place needle clip in mid-position.
    3. Start motor and run it on the stand.

    Condition: Motor running and main jet out. Needle or needle jet is correct: Carburetor should run clean to approximately 3/4 throttle. From 3/4 throttle to full throttle, the motor should start to break up as a result of too rich condition.
    Correction: None needed.

    Condition: Needle or needle jet is too rich. Carburetor runs clean to approximately 1/2 throttle but breaks up before 3/4 throttle as a result of too rich condition.
    Correction: Mikuni replace needle jet with next leaner and test again. Keihin replace needle with next leaner diameter and test again.

    Condition: Needle or needle jet is too lean: Carburetor runs clean beyond 3/4 throttle and has an erratic throttle response.
    Correction: Mikuni replace needle jet with next richer and test again. Keihin replace needle with next richer diameter and test again.

    The emphasis here is to find the correct needle or needle jet diameter, which will allow more fuel to pass than is needed but not so much that the needle itself has no control below 3/4 throttle.

    Step 2: DETERMINE THE CORRECT PILOT JET.

    1. Make sure the bike is warmed up if at all possible.
    2. Main jet out.
    3. Needle clip in mid position.
    4. Turn air screw all the way in then 1/4 turn out.
    5. Start motor and run it on the stand.
    6. Adjust idle so the bike will just barely idle.
    Condition: Motor running and main jet out.

    PILOT JET CORRECT:
    With one hand on the throttle maintaining RPM at approximately 1/8 throttle, turn air screw 1/4 turn at a time clock wise until you bottom it out. Motor should become slightly erratic and you should have to play with throttle to maintain RPM. Start turning air screw counter clockwise, 1/4 turn at a time until you have reached 2 3/4 turns out. Between 1 1/4 and 2 1/4 turns, your motor should have reached its highest RPM maintaining a steady throttle. Adjust air screw again between 1 1/4 and 2 1/4 until you have determined highest RPM. Quick throttle response should be clean without bog.

    PILOT JET TOO RICH:
    RPM does not reach a peak between 1 1/4 and 2 1/4 turns, stays the same or keeps rising out to 2 3/4 turns.
    Correction: Mikuni replace pilot jet with next leaner and test again. Keihin replace pilot jet with next leaner and test again.

    PILOT JET TOO LEAN:
    RPM does not become erratic and motor maintains throttle when air screw is turned all the way clockwise.
    Correction: Mikuni replace pilot jet with next richer and test again. Keihin replace pilot jet with next richer and test again. Remember, with a steady throttle approximately 1/8, there should be a distinct difference in RPM from 1 1/4 turns to 2 1/4 turns if the pilot jet is correct. The emphasis here is to find a pilot jet that will run crisp without bog and without the main jet.

    Step 3: DETERMINE THE CORRECT MAIN JET.

    The main jet selection process is easy once you have the correct needle diameter or needle jet. You now only have to correct a rich condition from 3/4 throttle on up and you know what a rich condition sounds like. Your pilot circuit is correct and without bog.
    1. Replace main jet with one that is at least two sizes smaller.
    2. Needle clip in mid position.
    3. Start motor and run it on the stand.

    By replacing the main jet with one that is too small, you are looking for a condition that is too lean. You adjust your main jet from a too small to lean condition.
    Condition: Motor running and main jet in.

    MAIN JET CORRECT:
    Carburetor should run clean and crisp to full throttle.
    Correction: None needed.

    MAIN JET TOO RICH:
    RPM reaches a peak slowly with a deep sound. Excess fuel and oil mixture at end of silencer. Spark plug fowls easily and is dark in color.
    Correction: Mikuni replace main jet with next leaner and test again. Keihin replace main jet with next leaner and test again.

    MAIN JET TOO LEAN:
    RPM reaches a peak quickly but erratic. A quick full snap open of throttle causes the motor to hesitate BEWAH sound or a complete bog. Motor sounds like it has a ring to it. End of silencer white. Spark plug is white in color.
    Correction: Mikuni replace main jet with next richer until the BEWAH bog just barely goes away, then replace the main jet with the next richer and run it. Keihin replace main jet with next richer until the BEWAH bog just barely goes away, then replace the main jet with the next richer and run it. The emphasis here is find a main jet that is just rich enough to allow you snap the throttle wide open without the motor bogging as a result of the main being too lean. Should be a quick crisp throttle with no hesitation.

    Step 4: DETERMINE THE CORRECT NEEDLE TAPER AND CUT AWAY.

    This step in the jetting process can be made very simple if you remain close to stock. However, your needle taper is adjusted for 1/2 throttle to 3/4 throttle. Start off with a rich taper (shallow taper angle) and keep going leaner (steeper taper angle) until it will not maintain constant RPM at 1/2 throttle (runs erratic). Go back to the leanest taper angle that ran the smoothest at 1/2 to 3/4 throttle and that should be the correct taper. The needle taper final test should be under track conditions with the greatest effect entering and exiting corners. Do not change the needle diameter or needle jet size during this process because that has already been determined. Adjust taper and throttle cut away only.

    Throttle cut away affects from idle to 1/4 throttle. The correct cut away will maintain steady 1/8 throttle with quick throttle response. Generally the stock cut away is very close. Experiment with different cut away until it maintains the best response to 1/4 throttle.

    QUICK TIPS:
    Keep it simple, buy the optional OEM needles or needle jets that are available, as this may speed up the taper selection process. Don't skip any steps or you're just guessing.

    FINAL THOUGHTS:
    That's it, if you spend the time jetting correctly, the benefits you will gain definitely out-weigh way the time spent. Take the guesswork out of jetting by following a procedure that has been given or one you have laid out yourself. Keep the black magic process out of your tuning tricks :hyp:and you will be better off for it.

8

Carburetor, Intake, and Exhaust / APT 40mm Billet Smart Carb mounted on a 431 Puma. With important mounting notes.

« on: November 15, 2014, 03:20:50 PM »

Started running the 40mm billet smart carb back in February 2014. The loaner carb had float bowl issues. After resetting the float heights it was not refilling the bowl quick enough. It would like just die at full throttle. Low and behold the tech at APT says it is very touchy setting the float height while still maintaining refill flow rate. The carb was real lean compared to a normal carb on the bottom end. Seemed to breath fresh air into riding in first and second gear. This prompted me into getting a 40mm billet for myself. Put her on and got her started. Seemed to be just a tad to lean so I proceeded to richen the clicker every couple hours fearing I was going to seize her up at WOT. From 1/2 to full throttle there was a stumbling spot. I contacted APT and requested a richer Fuel Metering Rod or FMR.

Received a new 76 FMR a couple weeks later and put it in to replace the leaner 78 FMR. I did not write down how many clicks I had the clicker set at. I was instructed to get the bike started going about 50 to 60 clicks from full rich. Then keep going leaner until the idle started to get angry. Like when your bike is running out of gas. It will rev up for awhile and then come back down a little and repeat. Once the idle gets a little angry you then set it 2-3 clicks richer until you have a perfect idle. Once you get a perfect idle you can then drop the idle speed down to where you like it at.

I was really excited now the FMR was richer and I hope to get the stumbling out of the 1/2 throttle area. Went out for the usual dune ride at Winchester bay. Was great 0 to 1/2 throttle. Was stumbling still at 1/2 throttle. When full throttle was achieved she ran great. I was still not sure what was causing her to stumble. Rode the rest of the day and figured I would ask questions on Monday. Kyle Burns put it this way summarizing where the clicker works.

My understanding is this is alot like a Lecton. But there is no jet.  You slide the FMR up or down to control idle to 1/2 throttle.  1/2 to full throttle I determined by the FMR itself.

So I went 3 clicks richer the next weekend. I get to the dunes and go to start her up and she just won't start. I notice gas dripping out of the header pipe. Had someone pull start me. Had to get pulled around the parking lot but would not start until I let off the throttle completely and just barely fired. It gets going and I go for another dune ride. After coming back and having a beer and refueling I go to start up again. Won't start. So I do the pull start thing again. Same results, like it was flooded. Went for another ride and same scenario. Was making chirping noises under full throttle. Like metal on metal as the train goes by. Would not start again after cooling down in the parking lot. Seemed strange if you stopped out on the dunes for a minute she would start right back up when hot. Loaded her back up and went home.

The next week I took the seat off and double checked the boot was sealing around the intake manifold. It seemed a little loose when I checked it out riding the weekend before and tightened the clamp. My thoughts were maybe it was loose and moved on me. After loosening and trying to move the carb forward I tightened it back up and turned 3 clicks richer, it actually started. Thought maybe it would not start due to extreme lean condition as stated in the manual.

Tried again the next weekend. Again the bike won't start so I got a pull start. Each time coming back for more fuel I just let her idle instead of hitting the kill switch. Just turned the idle up a bit. I had noticed after setting my idle at home I had to turn it up after getting to the dunes the last couple weekends. I went and gave her 3 clicks richer and was going to go do a plug check. As I got to 1/2 throttle just to about 3/4 open the piston froze up. SOB, did I go 3 clicks the wrong way? I got off the bike and started pushing her back to the parking lot. A guy rides up and asks me if I am out of gas. I look at him and say "I Wish" As I was sitting there waiting I kicked and the piston broke loose. Zero compression.

I'm like :wtf?:

APT says if the carb is hitting the frame it vibrates the carb not allowing it to atomize the fuel correctly. This week Kyle or Ryan was saying this creates a lean condition. So I went and took pics to show no frame touching.





Measuring from the carb to the intake is 3/4" in this pic
I then removed the boot and set it back to 3/4"



Now you can see the carb is touching the intake on the far side. This indicates to me that the carb touching the motor may do the same thing as the carb touching the frame. Even though no one mentioned this as a possibility. Heres a better pic so you can see how hard it is touching. The black sharpie line is where the boot was on the intake. It was up tight against the carb.



The plug is tan at piston freeze. I took this pic as I was taking the cylinder off.



So the whole time starting February until now (November) the carb has been experiencing the lean condition intermittently? (every 5 minutes)  I am guessing. Seems the aluminum has been eaten away on the exhaust side of the piston.

9

Pumashine 250R Products / 87-89 gusset welding pics

« on: October 11, 2014, 12:45:48 PM »

DOWNLOAD THE GUSSET WELDING THREAD HERE  https://www.forums.trx250r.org/index.php?action=dlattach;topic=4525.0;attach=2426




The 1986 front motor motor mount sub structure is a stout cast iron piece that may start fracturing from the frame. Fixing consists of just welding up the cracks. On the 87-89 sub structure the thin sheet metal design tends to start cracking at the inner corners just under the front motor mounts. This area is marked by a red line in the pic.



The thick small triangle shape pieces supplied in the 87-89 gusset kit are tacked in place just inside the frame up against the sub structure. This will leave room to leave a nice weld. The sub engine mount gussets reinforce the sub mount to keep it in place as it is subject to twisting and vibration. The twisting of e power full motors easily starts a crack in the sub mount. Weld the crack up and reinforce the sub mount with these small gussets.

https://oi345.photobucket.com/albums/p361/Tonygusset/DSC01364_zpsxeyfwwun.jpg

https://oi345.photobucket.com/albums/p361/Tonygusset/DSC01365_zpszphlznki.jpg

10

Pumashine 250R Products / Reinforcement rings

« on: August 09, 2014, 11:31:43 AM »

Hello, I saw in a few of your pics that your trx wheels had some sort of custom reinforcement rings welded in, did you cut those yourself? If so would you be able to cut me a pair?  Thanks for your efforts, Jason
Ac racing used to make a set with stars on them would this be difficult?
 

I used to use the cnc punch press and were limited to shapes of punches we had in stock. I cut these back in 2001.


With a little programming I can modify the star the resemble the one AC racing made as I can now cut them on the waterjet.

11

Engine and Bottom End / Bare aluminum motor look wanted

« on: August 02, 2014, 09:47:35 AM »

Whole motor...raw aluminium

Really? (pics?) Even if you had a spectacular bead bast finish wouldn't you want to put a coat a clear to keep it from oxidizing?

12

Pumashine 250R Products / Spare Tranny parts....

« on: July 24, 2014, 03:35:20 PM »

Just keeping track of what members need. I will dig out the spare tranny's and see whats available. Here are the notes for today. Lets me get all the spare parts together and see whats available. Thanks guys

silverlake250r needs 90454-KF0-000 .. is the one on the end of the countershaft... and 90431-HA2-000 the very thin one by 4th gear on the countershaft


Bio86 needs    #7 in the trans? Little bushing that 2nd gear rides on.

13

Engine and Bottom End / Motor years by case ID

« on: July 20, 2014, 03:22:09 PM »

The 85 to 87 years cases were cast a bit different up front where the front motor mount bolt goes through compared to the 88-89 years cases.The 85-87 has a narrow gap about an inch apart where the case halves come together. The 88-89 year cases have a much bigger gap which is over 3" long as can be be seen below on the green motor. To the left of the green motor there is a 1986 sivler motor.

14

Lounge / TRX250R.org first year celebration. 4 sets .org engine stand give away

« on: July 01, 2014, 01:43:30 PM »

To celebrate our 1 year anniversary we are giving away 4 sets of TRX250R.org Pumashine engine stands. And an additional 4 sets of different models have been added to give a better chance of winning.  Each person making a post in this thread will qualify for a random drawing. Entries will be taken until 12 PM 7-13-14. Winners will be drawn and posted Monday July 14.
The stand below is the one you will receive if you are a winner. (Cases not included) All you have to do is join and make 1 post.

15

Lounge / PM from Carlos concerning CP Industries products

« on: June 13, 2014, 01:49:53 PM »

I have not altered this PM without the exception the replacing another members name with Unknown

Pm the coc sent me

Thought you'd enjoy all the bs in the pm.


OK...sorry for not living up to your expectations. Try running a full Drag Port at 7000' first, then tell me our porting was not set correctly for 7000'...and if you wanted more top end, we would have done more work on the porting, and dome design as well as the pipe. What you will find out is a full Drag port on a single will not work well at 7000', the porting you got is very good all around, and Hill shooting while still living at 7000'.




As far as haters go...we have a few, interesting enough so does every other builder. Plus, if you really look at it with an open mind, you will see the so called haters that are BDT customers are 2 including you. Everyone else feeds of the 'frenzy' lies create. Plus; ask your self why we are the 250R & 2 stroke leading shop currenlty.Ask why CP Industries picked BDT to be sole sole distribuotr for Sabers, and eventually (end of 2014) Pumas, followed by Sphynx kits by mid 2015. Let me tell you why, because we are the ONLY shop that could afford to partner up with CP Industires, and the only shop that pays our bills on time. Note that they (CPI) was approached by the Top builders as well, yet they chose BDT...


If we built such 'bad' engines, and 'ripped' everyone off as a few would have you believe, then we would not be so successful. BDT is a 5 man shop...name one other builder that has more than 2 people working on these engines, just one. Hybrid=1 man, JH = 1 man, LED = 1 man, Shear = 1 man, ect...


This dude is such a clown they should call him bozo.