getting started tuning 94 610 TE: questions...

[bbbrrraaappp]

Hi everyone, I am new at posting but somewhat familiar with the forum. I've had this 94 610 TE for a few years but haven't ridden it much at all.

I live in Birmingham, AL, elevation 650 ft., high humidity, heat. I thoroughly cleaned the PHM40MS which is fitted with MJ 175 and 60 and 62 jets, the clip is on the 3rd notch from the top. Brand new air filter, airbox to intake boot and boot to carb tight. 93 gas with SeaFoam. For starters I backed the fuel screw 1 and 1/2. The bike starts very easily following the procedure I've read on this site: 4 or 5 kicks with decomp and a nice push thru from TDC. 72 degrees these days, didn't even need the choke for more than a minute. I intentionally set the idle a little high but not much really - just above the feeling that it could die, somewhat subjective...

I warmed the bike for 5 minutes gently riding thru 4th gear back and forth. All along, the transition from idle to 1/8 throttle is bumpy if not brutal. Once the bike warmed up, the issue persists although a little less forceful, but it's still there alright. Mid to 3/4 to wot is good. Once warmed up good, it has a tendency to want to die if I chop the throttle and stop, as if the idle forgot to kick in - kinda weird and not systematic. A little decel pop but nothing crazy
Along the test ride I switch killed it and started it again with no problem.

I have a few questions based on the material I've read here:

1./ Could it be the choke plunger issue? If so, which part wears off and needs replacing?
2./ I haven't checked the valve clearance yet. But I should be 100% sure of my carb first, right? Assuming the choke is not an issue, the clearance is 4 thousandth intake and 5 exhaust right? So should i play with the fuel screw before the valve clearance at this point or do the clearance first and then the carb?
3./ Are there other things I should look into at this point ?

Thanks to all for any info.!

 

[rancher1]

You should be able to get rid of the decel pop with the fuel screw. I would try 1/4 turns.

 

[Up-tite]

Choke cable should have lots of free play, with the bend over the carb that shortens the inner cable if not enough free play in the cable it will hold the plunger off the seat.
Always good to check these valves if run to loose they pot out the top of the valve and ding up the adjuster surface.
This is not good because if so cannot get an accurate adjustment.
Adjustment of fuel screw, get bike hot, get bike hot, get bike hot,
Set idle to what I call a dead idle just barely running, very low.
Turn fuel screw clockwise until it starts to stumble if it starts to rev up back out on idle speed screw until back to dead idle, continue in on fuel screw until it stumbles.
Once it stumbles counterclockwise until it stumbles then set it in the middle of the stumbling points, reset your idle to normal.
Many set idle to high for fear of stalling this can make it difficult to either start or restart.
Pop on decel is caused by air leak in pipe (slip connections,crack,lo back pressure in pipe as in opened up ) not a jetting function by adding more fuel in might stop the pop just that adding more fuel it makes the mixture to rich to pop off not really the correct jetting procedure.
Modern gas today is junk so don't get worked up if it's a little fuzzy, these motors were built when gas was ok, can try mixing some race gas to around 102-105 you can see the difference.
Later George

 

[Xcuvator]

Choke cable should have lots of free play, with the bend over the carb that shortens the inner cable if not enough free play in the cable it will hold the plunger off the seat.
Always good to check these valves if run to loose they pot out the top of the valve and ding up the adjuster surface.
This is not good because if so cannot get an accurate adjustment.
Adjustment of fuel screw, get bike hot, get bike hot, get bike hot,
Set idle to what I call a dead idle just barely running, very low.
Turn fuel screw clockwise until it starts to stumble if it starts to rev up back out on idle speed screw until back to dead idle, continue in on fuel screw until it stumbles.
Once it stumbles counterclockwise until it stumbles then set it in the middle of the stumbling points, reset your idle to normal.
Many set idle to high for fear of stalling this can make it difficult to either start or restart.
Pop on decel is caused by air leak in pipe (slip connections,crack,lo back pressure in pipe as in opened up ) not a jetting function by adding more fuel in might stop the pop just that adding more fuel it makes the mixture to rich to pop off not really the correct jetting procedure.
Modern gas today is junk so don't get worked up if it's a little fuzzy, these motors were built when gas was ok, can try mixing some race gas to around 102-105 you can see the difference.
Later George

Good stuff George.

I always had some popping whether EFI or FCR41 0n my 610s. Less popping with the richer (powered up settings) of course.
The latest version of the Lectron 4st gets as good mileage (07) as the EFI 08 I had, runs strong and no popping or hanging idles.
I tried 5 or 6 lectrons over 20 months or so when I was working with Kevin Gilham from Lectron. He did a lot of work on the dyno and I really think he nailed it.
Oh and I tried the Lectron on my 05 TE 450 too and it ran really sweet.

BTW
Both my 05 TE 450 and 07 TE610 had FCRs that had been worked over by Ron Black with JD needles. They ran good but much better with the Lectron.

I realize you are talking about a different animal but I can't help but think the older 570/610s might benefit with a Lectron.

 

[ryboj]

Good stuff George.

I always had some popping whether EFI or FCR41 0n my 610s. Less popping with the richer (powered up settings) of course.
The latest version of the Lectron 4st gets as good mileage (07) as the EFI 08 I had, runs strong and no popping or hanging idles.
I tried 5 or 6 lectrons over 20 months or so when I was working with Kevin Gilham from Lectron. He did a lot of work on the dyno and I really think he nailed it.
Oh and I tried the Lectron on my 05 TE 450 too and it ran really sweet.

BTW
Both my 05 TE 450 and 07 TE610 had FCRs that had been worked over by Ron Black with JD needles. They ran good but much better with the Lectron.

I realize you are talking about a different animal but I can't help but think the older 570/610s might benefit with a Lectron.

If my experience with the 360 2 smoke goes well with the Lectron that's coming in the mail, I may do the same to my 00TE410, which is very close to the 610. I'm thinking Lectron has it darn close, so little fiddling is necessary, but that's about it. Should just be a better overall experience, in starting/riding, getting rid of some of the stock carb nuances.

Great thread on tuning here too!