87r problems II

[jcas]

Got the R back from the shop.......no air leaks! Jetted up to a 205 main and at WOT the plug is still ashy white. The bike has a ESR 310R bored twice, cool head w/ pump gas dome, 38mm airstryker, ESR airbox eliminator, cr reeds and cage, and trx6 pipe. I run a br8es plug at .018. ESR told me the cdi may be screwing up, that it could be throwing the timing off. I'm going to put the 36mm pj back on and see what happens. Any suggestions?

87 310
83 R
81 200

[slick250]

It has to be either an air leak or a fuel restriction through carb.:ermm:

[zedicus00]

who put the cr reed cage in it? was it ported to fit the trx boot? if not it is a huge restriction. ive heard of bigger jets on 300+cc motors too. i wouldnt go back to the 36 pj that carb is all wrong for that engine.

[papatrx]

Your jetting at 205 is not that unusual, I have seen bikes with much higher mains than that. There is no way anyone here can tell you what jet you should be using. I have 6 250rs and have ported them all myself to slightly different specs and run them all at the dunes on the same hills at the same time in the same temperatures and the jetting ranges from 168 to 195 and they are all 66.5 to 67 bore sizes which are not near as large as yours. You have already ruled out an airleak which is the first main area to look into. I have changed all my bikes to use the 88-89 cdi box, they do rev higher and are slightly larger. You should try jumping 5 or 6 sizes higher on your main jet and see if there is any color change on a fresh plug.

[deathman53]

I was using a 205 in my atc250r with a esr330, it sounds a big high, especailly to have a white plug. there is somehting wrong, I agree defintley a fuel restriction.

[JTRtrx250r]

Originally posted by papatrx
Your jetting at 205 is not that unusual, I have seen bikes with much higher mains than that. There is no way anyone here can tell you what jet you should be using. I have 6 250rs and have ported them all myself to slightly different specs and run them all at the dunes on the same hills at the same time in the same temperatures and the jetting ranges from 168 to 195 and they are all 66.5 to 67 bore sizes which are not near as large as yours. You have already ruled out an airleak which is the first main area to look into. I have changed all my bikes to use the 88-89 cdi box, they do rev higher and are slightly larger. You should try jumping 5 or 6 sizes higher on your main jet and see if there is any color change on a fresh plug. ;) ...yup, if not ...see what the old carb does

Did you ever find out what your compression was?

[jcas]

Put the 36 back on with a 190 main. Did a plug chop at WOT and the plug was tan(thank god). Didn't push it too hard, it was getting dark and I'm still scared of frying the motor. Could the ignition cause all of this? Would it effect low and mid throttle? At those speeds the plug is a dark tan. It all started when I put the 38 A/S on. Seems like a HUGE coincidense that the ignition would go bad 5 minutes after I put the A/S on. Papa and Zedicus, what main should I try in the A/S? What main would surely be too rich? Thanks for all the help.

[zedicus00]

on the A/S carb maybe u should adjust the needle position or try a different thinkness needle. i spose the ignition could cause similar problems but if it is not doing it with both carbs then u could rule the ignition out. as for jetting i would say a 300 main would prolly be too rich :p do they even make one of thouse? the point is every quad/location/ elevation/temperature is different so jetting will be different. im slightly rich with a 175 main on a wildly ported 246cc engine with a 39mm carb. but that doesnt matter to u u may need to run a 240 to even be close. jetting is a mysticle art to be compared to pure magic.

[jcas]

Okay. Tonight I put the the old reed cage and intake manifold along with the 36 mm pj. I jetted the pj to 195 main, 60 pilot, needle clip at the bottom position(richest). Brought a good flashlight with me and out we went. IT'S STILL LEAN!!!! I put everything back on the bike that was on there prior to the 38 A/S. I had the pj jetted with a 175 main before and the bike was perfect. No way that's not enough fuel. Checked the fuel line and fuel hose. No problems there, they are new anyway. There's no airleaks, had a shop check that. Next step......new 87 cdi. Wtf else could it be? Anybody here ever had an ignition go out? ESR said that when there's a problem with the cdi, some people have to jet really low and others had to jet really high to get the bike to run okay, something about the timing. Any experiences? Thanks guys.

87 310R
83R

[JTRtrx250r]

I really hate burning thru new gaskets to test but it usually ends up to be WAY less than burnt up motors,

sounds like its gotta be the CDI or statorplate

[CARLSON]

I HAVE A ESR 310CYLINDER TRX9 PORTING 38MM AIR STRYKER,V FORCE REEDS,ESR INTAKE,AND A TRX9 PIPE AT THE OREGON DUNES I RUN A 172-175 DUE TO WEATHER VARIANCE AND A 55 PILOT.I GOT THIS JETTING BY DYNO TUNING

[beerock]

i have jetted my buds 310 and hes around 185 at sealevel with mx porting.

CHECK THE WIRES

my bud had his hot wire hanging on by two strands and the plug kept coming back white

[slick250]

Originally posted by CARLSON
I HAVE A ESR 310CYLINDER TRX9 PORTING 38MM AIR STRYKER,V FORCE REEDS,ESR INTAKE,AND A TRX9 PIPE AT THE OREGON DUNES I RUN A 172-175 DUE TO WEATHER VARIANCE AND A 55 PILOT.I GOT THIS JETTING BY DYNO TUNING
I have the EXACT same setup as Carlson and I run at Little Sahara, OK with a 172 main and it is very close to perfect, but leaning toward the rich side.

[slick250]

Air leaks on a 2 stroke can be hard to find. you have to consider all crankcase seals, gaskets, cracks in case, or any other possibility for the crankcase to pull in air due to the intake charge being drawn through the crankcase.

[beerock]

he already ruled out a air leak, unless the shop didint do a proper leak down test

[slick250]

Thats kind of what I'm getting at;)

[beerock]

what kind of gas are you running? is it aviation fuel?

some additives in av fuels make the plug white

[jcas]

I bought the race gas and pump gas dome from ESR. I'm running the pump gas dome right now with 91 octane. ESR said that's not a problem. I am going to check my compression though. Is it anything over 190 compression requires race gas(110 octane)? Ordered the CDI, should be here by tues/weds. Got my fingers crossed that that's it. On monday I'm going to check all the wiring to make sure it's ok. I remember I did pull off the taillight wires and set them aside, then put them back on after I installed the airbox elimator. I also took off the headlight and ziptied the wiring to the frame. But this was awhile back and the bike wasn't giving me no problems. Thanks for the help.

[papatrx]

Back to your leak down test, first did you witness the test? The engine should hold 8psi for at least 10 minutes. When they did the test did they spray the engine with simple green or some sudsy solution that would easily show a small air leak. Even a small leak will easily show bubbles when only dropping a couple of psi over a 2 minute span. I would never just drop off an engine and let them do something as crucial as a leak down test and not be there to witness it, I am not nocking your shop, just saying there are way to many dishonest shops looking for a quick buck.

[jcas]

I didn't witness the leakdown test, but they told me it held and there was residue from the solution they used around the motor to check for leaks, but I know they could have just sprayed it. Anyway I replaced the cdi and did a couple of runs. The plug looked better, but that was with a 190 main in a 36mm pj. Going to try it again tommorow. The cdi is brand new for an 87, but it's smaller than my stock one. Going to take it back to make sure it's the right one. I'm running out of things to do. Could the stator or flywheel cause the motor to lean out at high rpm? Could the wiring harness be shot? What else?

[JTRtrx250r]

I ran into a simple but nerve racking thing 1 time, turned out to be too long of a vent hose from the gascap and it was plugged up(steering stem FULL of mud/water/sand/rust)....but I really dont think thats your prob

I mentioned the stator b/c of a similiar situation...except the motor seized up 3 or 4 times before I bought it, about the only thing left to swap out in the system was the stator, did it and that motor still rips..that was a few yrs ago

Hate to see you keep spending but thats whats gotta be done sometimes, not saying thats your prob, but could possibly be. Its the process of ilimination if nothing else

Are you positive you got the right dome in it? Floats out of adjustment or sticking maybe?

Ive seen a bad killswitch do some weird things but thats prob not your prob either..

I say make your own leakdown tester so you'll be able check anytime( I gotta do the same...still LOL)

[JTRtrx250r]

heres a link for the LDT http://www.off-road.com/atv/ptester.htm

[papatrx]

What's the history on the bottom end, did you put all new bearings and seals in when you installed the ESR kit? The crank seal on the stator side is very prone to leaking and must be installed just right and not cover the air tubes to the bearings. I have a buddy with an 86 bottom and a LA sleeve ported for drags. He had the old CDI and the stock coil which is very weak and we continually were jetting down because we would not get a good complete burn and also blubbered on top...typical rich jetting scenero. We put my 88 CDI on which cleared up some of the blubbering on top and added my coil which is the one from Janseen which totally cleared up the weak spark and allowed us to jet way up and also open up the plug gap to .028. What I am getting at is if you have a weak ignition I don't see how you are showing a lean condition due to a weak spark it should go the other way. When jetting you should start WAY WAY fat and work your way down not lean and work you way up. Try like a 240 just to give yourself a baseline to work from. If you are still lean at 240 you probably for sure have an air leak somewhere.

[beerock]

i coudnt see this motor taking a jet bigger then a 210 honestly, unless the port job calls for it.

[beerock]

my buddy had this EXACT problem and i said it before, it had something to do with the wires that supplied the cdi power.

for some reason it was showing lean conditions due to a short(2 strands holding the power on) we fixed the wire and it went away. it ran a 185 in it once jetted right.

we went up to a 220 main would still be lean.

it could possibly be the same problem your having.

[jcas]

Which wires did you change? Let me know so I can change them. Today I noticed that the tranny fluid was low, so I filled it and took her out. Checked the plug and there was a lot of oil on it. Also where the plug goes on the head, there was a lot a dark residue on it also. So it's BACK at ESR getting that seal changed. Keep the help coming guys, I need it.

[beerock]

if its at esr have them look over the whoel thing. i dont know what wires are bad on your just make sure the connections are all clean and wire is good