Problem!!

[TEMPESTRACER1]

I posted earlier that my newly rebuilt engine was running very rouh. I did find that the counterbalancer was out of time and thought I had a jetting problem.The bike will run decent at half throttle but when you try to go full throttle is just craps out and sputters. I have tried several different jetiing combos and two other carbs and have the same symptons. Any ideas because I am at a loss.

[Saul76]

Plug properly gapped?

Maybe your coil gets bad when it gets hot or under load at high speed? A bad electrical problem can give 'rich' symptoms.

Just a thought.

Good luck.

[TEMPESTRACER1]

I took the coil off my other R and tried it and no change.What is a good plug gap.I am running a NGK8 series plug.

[250r grave yard]

Originally posted by TEMPESTRACER1
I took the coil off my other R and tried it and no change.What is a good plug gap.I am running a NGK8 series plug. are they br8es

[trx310R#24]

reeds, flywheel stator, fly wheel pin. check there to.

[TEMPESTRACER1]

The plug is a BR8ES.I changed the reeds also and has the same symoptons.

[Saul76]

Originally posted by TEMPESTRACER1
The plug is a BR8ES.I changed the reeds also and has the same symoptons.

check the ground. Take it off, clean up the area and try again.

[250r grave yard]

repost what you have on your bike and what you have done so far so we can help you better on your problem and have you check your electrical to see what ohms you getting

[TEMPESTRACER1]

The engine was completely rebuilt.New hot rods crank and rod assembly,new bearings,seals,stator,stock bore,38mm carb,new clutch.etc.When I got the engine back it had a bad vibration so I took it back and the counterbalancer was out of time.Got that fixed but it just wants to bust out real bad.My jetting now is at 148 pilot and 168 main and the plug looks to be good but just runs terrible.I have not checked the electrical system cause I really dont know how to go about that.Is it a possible for the engine to be out of time??The bike is an 88 if that matters.

[250r grave yard]

did you have some one build it for you or you got the bike from someone i have posted a detailed intruction on how to do your electrical let me look for it what pipe you have an is that an a/s carb you have

foundmybook 1986 1987 1988 1989


below 5000ft #150 #152 #158 #155
3300-6600ft #148 #150 #155 #152
above5000ft #145 #148 #152 #150
slow jet #48 #48 #45 #42

1986 &1989 call for a br8es 1987 & 1988 call for br9es


the ingnition timing also changed in the years of the 250r 1986-1987 is 19 degrees BTDC and 1988-1989 21 degrees BTDC

now for the how to check ur pulse generator , exciter coil , and the stator

to check the exciter coil dis connect the black/red wire leading to the stator and put one on the black/red wire and the other the on ground/frame . the ohms should be anywhere from 50-250 ohms

to check pulse generator disconnect the blue/yellow and green/white wire .then connect the leads to the 2 wires and should get back 50-200 ohms

to check stator detach black/yellow and green wire from stator . Disconnect high tension lead (coil wire) from spark plug .To check primary winding resistance , attach one ohm meter lead to black/yellow wire on stator and the other lead to green wire .Should read 0.1-0.3 ohms . Perform 2 secondary winding tests ,one with spark plug cap attached to coil wire and one without spark plug cap attached . Attach one lead to spark cap and other lead to the ground (green wire ) .Secondary winding test trhough cap should be 7k-11k ohms . Then attach the lead to high tension wire and the other lead to the coil ground . Should read 3k-5k . hope this helps you out

check your compression had that problem with my blaster when i first started workin it i could get it to fire but wouldnt run for long. the compression kit is only 30 bucks get it at any auto store . when you check it check it with wide open throttle and should get a good reading with 4-6 kicks should be 110 -130 for a stock piston and head

[TEMPESTRACER1]

I have an LRD pipe and silencer. I had someone build the motor for me.I am going to check all the electrical tomorrow and go from there. Thanks

[250r grave yard]

hope he dont build motors for a living building you a motor and it be off timing

hey is the piston on backwards just a thought

check your wires see if they are color coated some of them look almost alike when they get old they can get crossed up some times

[TEMPESTRACER1]

I think I might have found the problem. When they built my engine they said my cdi box was bad.They had one there at the shop so I got it . I have an 87 r with a new cdi on it so I put it on first and tried it and the bike would not hardly run at all just bogged around.I then tried the one they give me and the bike still has that bogging problem.Is it possible they gave me the wrong cdi for my 88? Is there a difference in the 86-87 cdis and the 88-89 cdis??

[RyanWsly]

If you suspect wiring, I would either swap engines frame for frame or wiring since you have another to play with. The wiring and cdi and all that will work, I have used a 85 wiring harness and all the parts on a long rod before, talked to the guy that has it now, by chance the other day, said it just eats 450's, sounds like it runs fine......... If you can't make it run by swapping, I would take it and pound it up that guys ***.

[TEMPESTRACER1]

If they give me a cdi box for an86-87 would it not work on an 88?The box on my 87 plugs right in but the engine just bogs when you take off.

[Saul76]

Have you checked compression?

Have you checked the ground?

Have you tried going smaller and smaller on the main jet?

Is your plug cap making a good and tight connection with the plug? (I changed plug caps once and at 'speed' the plug would wiggle on the plug making the trike sputter)

Did you properly gap the plug?

[RyanWsly]

yes any year should make it run, my point was that I used one off a 85ATC which even has different connectors and a totally different CDI, physically looks different. If you order an aftermarket one like a Dyna Tech one it will fit all years 86-89 if that helps. If your other bike runs fine with the other CDI this one should too, if you think it is wiring transfer the harness and all it's parts, start with a known good system,then you can weed out the bad piece if needed, easiest way to troubleshoot the thing if you struggle with wiring.

[TEMPESTRACER1]

So it doesnt matter what model the cdi is it will work on all years?

[matt250r21]

Check the c-clip on the needle of the carb slide. I had one crap out on me once. The needle would stay down in the main jet when I tried to rev the bike up and it would run real bad.

[250r grave yard]

just was brain farting maybe your head is leaking usaully when you have a head problem its at high rpm check your fluid or see if the plug is wet

check to see if your case halfs are leaking or clutch side seal can be leaking

[TEMPESTRACER1]

I swapped the wiring harness off my other R and no change,Changed coil,same symptoms,Compression is good,all bolts tourqued.Same symptoms.This engine use to be a 310 and I put it back stock bore.I am running the same 39mm A/S carb that was on the big bore.I jetted this thing to a 35 pilot,145 main and put the needle in the leanest setting,ran better but still busts out.It seems to clear out up in the higher gears 4,5,6.Is this carb just too big for the stock bore??

[250r grave yard]

do you have any porting ?

but i dont think it would cause you to have the problems your having

and i dont think they made a 39 a/s inless it was bored

what slide do you have , needle ?

does it smoke alot or clear up in higher rpms maybe sucking in oil from your clutch side you did have problems with your builder no telling what he did to your motor !

did you have a spacer plate on the 310 take some pics of your new setup

[TEMPESTRACER1]

It does have some mild porting.The 310 did have a spacer and the stock cylinder does not. I cant remember which needle and slide are in it but I can check and let you know.The carb measure aliitle over 38 so maybe its a 38.Does smoke and has blow by build up under the pipe on the engine.

[TEMPESTRACER1]

THE SLIDE IS A NUMBER 7 AND THE NEEDLE IS A D

[250r grave yard]

the needle says D no other letters

[TEMPESTRACER1]

Sorry,it says DD

[250r grave yard]

get the needle DGH and try that i believe thats what comes in all a/s carbs but i stil believe that its more than the needle but try that and see

and when you said it just busts out when you riding it what do you mean by that ?

[TEMPESTRACER1]

It just kinda sputters and acts like it tries to take the fuel off and on in 1st thru 3rd and 4th thru 6th it starts to clear out if you keep it WOT.

[250r grave yard]

hey check your reeds they might be stuck open i dont think anyone suggested that yet and the carb shouldnt be to much for that setup i ran a 38 a/s on my 40 over bore with a pipe that runs stock jetting and my comp was at 150 what is your compression at take some pics of the parts and is your piston getting scared at all any signs of wear and when i had a problem with my blaster leaking seal it would run like that had to be in the upper gears in order for it to clear up im think your builder so called builder like if he is one prolly didnt change the seals on the crank