MaineDirtbikes.com Forums / General / Mechanical

more air flow!! read for details

2fast4u13 — Wed, 18 Jun 2008 20:45:11 GMT

for more airflow u take ur seat off when u ride to get more air into the carb and run no filter so that doesnt hold back air for the carborator i did it in my car to which cause it to gain more hp i think u get 15-20 more hp just something to try to be at the top of the rank

Whats the best lube for slow throddle cable?

cr250r2stroke — Tue, 25 Mar 2008 10:39:29 GMT

i got a sticky throttle cable that snaps back really slow...the cable looks in greatshape every where but is just really slow ...what do ya think i could use on it...to get it zinging snappy again:D

How to change clutch plates on CRF150R MUST KNOW BY TOMORROW!!!!

#27rider85 — Fri, 09 May 2008 19:13:12 GMT

I MUST KNOW HOW TO CHANGE THE CLUTCH PLATES ON CRF150R BY TOMMOROW MAY 10TH.
MUST KNOW FAST RESPOND OR CALL 207-862-6336

Breaking down a YZ 250 to the frame

Devil1 — Mon, 05 May 2008 05:29:20 GMT

How hard/labor intensive is it to bust a YZ 250 down to parade rest? I was thinking of powder coating the frame. Anything I should know?

Best Chain for Dollar

Pat P Diddy — Wed, 09 May 2007 14:30:34 GMT

Can somebody recommend a chain that is the best buy for the dollar based on some scientific fact (ie: not just your favorite brand but which chain costs the least money but lasts the most hours). For example I average 13.08 hours for my renthal chains and they cost $69 so that ends up being $5.28 per hour of operation. At one point I had tested an RK chain and was able to get 33% more life out of it but can't remember how much I paid for it. Does anybody else track life expectancy of parts like I do?

top end rebuild Q's

eltigrekid — Sat, 03 May 2008 14:31:01 GMT

im in the process of doing a new top end on my 02 rm 125 , and im basically done. the problem is the power valve rod, i think its called, that goes up the side is pulled up kinda high, i think i did by accident, but it wont move up or down now it seems to be stuck, and its to high to mount back onto that spring thing. any help would be greatly appreacaited, thanks.

Anyone ever used a Keihin PWK 38mm Airstriker carb Honda CR 250

cr250r2stroke — Mon, 07 Apr 2008 11:34:27 GMT

Im lookin at a Keihin PWK 38mm Airstriker carb Honda CR 250 on ebay has any body ever swaped out their stock Stock Mikuni TMX carb for one of these. let me know:D

Cold weather starting

Pat P Diddy — Thu, 27 Mar 2008 18:26:15 GMT

I'm having trouble starting my 250F that was in my cold garage all winter. Last year about this time I had to borrow one of those heavy duty shop heaters and put it next to my bike and heat it up for several minutes to get it started... is there any easier trick? I decided not to sell it so hoping to ride it at Southwick. Thanks!

'07 yzf 250 drain bolt issue

mxsmall2708 — Wed, 19 Mar 2008 18:51:08 GMT

So the other day I was changing my oil in my bike and I was screwing the bolt back in (with my fingers) and it was not tightning up. It felt like I had a screw that was too small in there so i unscrewed it thinking i had mixed it up with one of the 7 other bolts you have to remove to drain the oil.

Upon removal i noticed the bolt had a small shaving of metal on them.....known as the threads.

Has anyone had any problems with this, the threads on the bolt are fine so i know i didnt crossthread it, i was screwing it in with my hand..........

Last year someone had asked me if I had, had problems with the welds in that area, i guess theres didnt hold and all the oil leaked out, i dont really remember. but I'm wondering if that whole section of the bike has a problem with it, becuase I had just warmed it up. I'm wondering if maybe the heat softened the metal or something and the threads came out.

so if anyone has any information on it that would be greatly appreciated!

Snowmobile Oil - Safe brands

Pat P Diddy — Wed, 27 Feb 2008 11:53:45 GMT

Ok I just spent $25 for a gallon of Ski-Doo 2-stroke oil and I'm tired of getting raped. Most Ski-Doo people say I must buy the Ski-Doo oil or I void my warranty but it has long since expired...

What's another safe brand of oil to use that is less expensive? Do I really need to buy the Ski Doo stuff? I wouldn't think so... thanks.

Replacing fork seals

cr250r2stroke — Thu, 28 Feb 2008 16:21:32 GMT

hey there im think about buying a 2002 cr80 for my girlfriend and it needs fork seals .they are inverted shocks .the seals are cheep. ive done them on an old kd80 and it was kinda a bioch...any suggestion on how to do it or if i can do it...?

Thanks

:w00t:

Showa 37mm inverts

Kurlon — Mon, 07 Jan 2008 17:10:54 GMT

Two part question.

#1 - Can someone get me some dimensions off their Showas? Specifically I'm looking for lengths of the 37mm inverts on most of the 85cc class machines. I'd like to know the length from the top of the lower clamp to the bottom of the upper stanchion, as well as the length from there to the axle. I'm doing a custom application and would like something better/beefier than 35mm Marzocchi Shivers, but I need to make sure I can get the forks short enough to fit.

#2 - Any of the local suspension guru's up for cutting the travel on said forks? I know I'll need custom springs as well. Ideally I'd like to work with someone who can possibly make a custom clamp set, as well as an axle, spaces, and caliper bracket to fit a wheel I've got. If someone can ballpark pricing on any bit of this, I'd love to know so I can estimate how much my sickness is about to cost me. : )

Polishing frame cr 250

cr250r2stroke — Mon, 19 Nov 2007 10:12:11 GMT

Hey there i have a 2002 cr 250 and am looking to polish the frame , just wondering if anyone has done it and know where i should start or and any details on how to do it would be awsome..tks :D

Motocross Bike Repair

G117 — Sun, 14 Oct 2007 16:07:23 GMT

[center]G Performance Repair[/center]

I am looking for customers. I am offering my mechanical abilities to those that are not comfortable in working on there bike. The services that I have to offer are basic repairs to complete engine overhaul. If you need my services please email me [email]g-performance@hotmail.com[/email]:smooooth:

kawasaki oil gauge

Chamberlain 924 — Fri, 28 Sep 2007 14:16:02 GMT

the little glass oil gauge in my 07 kawi 250f has a little tiny crack in it. its barely leaking out and i rode it around a little to make sure that it wasnt too bad. is this a big problem or do you guys think i could finish off hemonds and 207?

Start up problem 97 YZ125

Ryan314 — Sun, 15 Jul 2007 19:49:52 GMT

I am soooo tired of this! My 97 YZ 125 has a brand new top end and the bike runs absolutely fantastic, no problems when riding whats so ever, never fouls plugs, very crisp, it's perfect. But, every friggen time I go to start the bike up the next day after riding or whenever (overnight, 2 days, week, whatever) it fouls the plug. I always shut the gas off too. It will start up first kick, but after a minute or so, it will bog out and die. I tried shutting the choke off immediatly after start up, but it still bogs out. So I have to change the plug, then it runs great. What is the problem here?!? I just can't see it being a jetting issue because the bike runs absolutely fantastic. I run Yamalube at 40:1 and use a BR7ES plug.

Please help me fix this problem!!!

'04 CRF450F burning oil

thumper404 — Sun, 26 Aug 2007 18:27:20 GMT

I've got an '04 CRF450 that's burning oil. I've replaced the valve guide seals twice, checked the head and the top of the cylinder for warpage, measured the cylinder for diameter and out of round, measured the piston diameter, measured the ring gap, replaced the rings and honed the cylinder. I can't figure out why the thing still is burning oil. Someone told me that I'm not supposed to hone a Nickisil(spelling?) cylinder. Does anyone know if this is true? Could this be the cause of my problem? The cylinder was honed the first time last year and ran good for a while. I honed it again after I started having problems but nothing helped. HELP! The season is almost over and I've only got one race in.

YZF handling

Motoxdrummer645 — Sat, 18 Aug 2007 23:36:51 GMT

Does any one have any suggestions for handling and cornering on a yamaha 250F?

suspention

Chamberlain 924 — Sun, 12 Aug 2007 21:21:25 GMT

where should i take my bike to have fork seals replaced with out driving to far? either pro action or factory connection.

Valves

kyleM258 — Mon, 16 Jul 2007 21:19:10 GMT

I have a 05' CRF250 and the valves were just adjusted after problems with starting and this fixed the problem but They already need to be worked on again. I rode a couple days and raced valley sunday and i needed to bump-start my bike by the end of the day to race it. What does this mean? if there is a serious problem who should work on it? I heard dillingham is good. Thanks for any feedback.

Paint

#27rider85 — Thu, 28 Jun 2007 15:31:51 GMT

Is there any special paint you can paint onto plastic????? Without airbrushing???

KLX110 Springs

yamahayzrider93 — Sat, 02 Jun 2007 14:34:41 GMT

Im tying to chane the shock spring on my 110 but I cant figure out how to get the spring off. It didnt come with directons and im about to throw it through the windo. Has anyone changed them before?

Grips

KXrider — Mon, 05 Mar 2007 19:18:37 GMT

Do you have to cut your grips off to change them? How do you put them on?

Thanks

CRF250 Starting woes

Pat P Diddy — Fri, 20 Apr 2007 08:02:43 GMT

Ok I thought my starting issues were just cold weather related but last night I couldn't start my CRF250... for the third straight time riding I've had to jump it by pushing it. This time two guys helped push me down a flat road. Once it's started and warmed up it rips though.

Any ideas?

Crf 250 transmision

MADracing926 — Thu, 03 May 2007 20:53:37 GMT

I just put a new clutch in, but problem not solved.. When i'm flying around agressively I have a hard time going from second to third and so on.. Its like after 2nd there's no more gears, the shifter dont want to move up. If i go down the track like granny I can run through all the gears smoothly.. I have been on other bikes. they dont do this! so its not me.. Anyone have any thoughts?

Jetting? (ttr225)

225er — Tue, 24 Apr 2007 09:26:42 GMT

I checked my elevation and its around 155m or 465ft. I have my snorkel pulled out of my airbox, an fmf powercore pipe and may soon get a twin air air filter. what would be better jetting? ive heard of people on thumpertalk re jetting and air box modding a ttr 225 and can easily crack a wheelie now. anyone have stock jetting numbers? recomendations?n thanks, 225er

Cold starting

yamahamx684 — Wed, 07 Feb 2007 16:59:09 GMT

Has any body else had problems starting there 4 strokes in this cold weather. I couldnt get my 06 Yz250F to start this afternoon, do u think its the cold weather?

Honda CRF250 Leaking Coolant

Pat P Diddy — Sat, 24 Mar 2007 18:23:26 GMT

I thought I just bought a fantastic deal on a 2006 Honda CRF250 but as soon as I got it home and ran it for a few minutes coolant started flowing steadily out of the overflow tube. I tried putting a different radiator cap from my CRF450 but that didn't work. Somebody told me it's probably a bad head gasket but another said that the oil should look cloudy if that's the case which it doesn't.

Any theories?

RM 125 question

mx207 billy — Mon, 26 Feb 2007 11:19:00 GMT

i heard a rumor the weak link in late model RM125's is the reeds. does anybody know anything about this? i was told replacing them with a Vforce reed valve is the way to go with these bikes.

250 four strokes - how often do do bottom end work

Pat P Diddy — Wed, 21 Feb 2007 12:29:05 GMT

I'm thinking about buying a 2 year old CRF250 four-stroke. It has a fresh top end but no bottom end work. To you other 250 four stroke owners how often do you redo your bottom end? Should I even worry about it?

Need help (suspension)

hndracer14 — Wed, 14 Feb 2007 17:21:22 GMT

I got 3 bikes 04,05 and 06 crf250's the 04 and 05 have some hours on them and need the suspension done but i need to have the 06 set up too. Im wondering what i should do for them if i shud just change the fluids on the 04 and 05 or get them redone and do i need to put new springs in the 06 any help is appreciated