Slide height screw (idle) - Page 2

**JerryHawk250** · 04-26-2022, 04:02 PM

Quote:

Originally Posted by Thumper

A replacement carb cost under $40, and I think I can shave a mm or 2 off the body without destroying it. That would allow the screw to get deeper.

It is not that bad, and actually fine once warmed up, but I may try it. Good idea.

You want to have the idle around the 1500 rpm range. If the rpm's are too low the pump will not send enough oil to keep the engine lubricated sufficiently.

Thumper · 04-26-2022, 07:44 PM

Quote:

Originally Posted by JerryHawk250

You want to have the idle around the 1500 rpm range. If the rpm's are too low the pump will not send enough oil to keep the engine lubricated sufficiently.

Then I definitely need to shave that mounting post down! Good call Jerry

I just came back from a test drive in my favorite housing construction park. TBR7 is geared down! But I am only running it carefully for "diagnostics"

I had fun. I am breaking it in for my son, making observations for control adjustments, listening for noises (I have a new list!).

But this bike is nice. Shifting is stiff if you don't know what you are doing. This will get better. Neutral easy to find rolling to a stop!.

su98 · 04-30-2022, 01:13 PM

so my question is what is a proper idle RPM? 750?

Thumper · 04-30-2022, 06:20 PM

I have always gone by ear, and drop it to a relatively low stable idle.

But Jerry has a good point... oil pressure! If the oil pump isn't generating enough pressure, bad.

I don't have a tach. I do have a tach I use on my chainsaw, which is triggered by induction (a lead wraps the spark plug wire). But I might just go by ear.

1. I never let it sit idling for more than a minute and don't mind letting it run HIGHER than normal while sitting/warming up for better oil pressure.
2. Then, I will set it for lower rpm for when I am actually riding it. It generally doesn't sit idling for more than a few moments during a ride.

I always adjust the idle when I ride it, first to elevate the idle during a brief warmup, and then to set the idle once warm (warm enough).

Thumper · 07-08-2022, 06:37 PM

Quote:

Originally Posted by JerryHawk250

Oh, I see what you are talking about now. I just noticed the screw head was hitting. Try filing or grinding down the case some so it can go in farther. At this point it would hurt to try.

Jerry,
Your suggestion to file down the case (stem that the idle screw threads into) a couple of mm is an excellent idea. We had the carb out and the slide is fine. The BEST solution would be a brass idle adjustment screw with a pin that is a few mm longer!

It is so hot in the garage right now, I hesitate. And, that also means it starts right up and doesn't NEED the idle elevated. I'll wait for colder weather

04-30-2022, 01:13 PM	#18
su98 Join Date: Apr 2022 Location: Pittsburgh Posts: 58	so my question is what is a proper idle RPM? 750?
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04-30-2022, 06:20 PM	#19
Thumper Join Date: Feb 2021 Location: Kansas City Posts: 2,237	I have always gone by ear, and drop it to a relatively low stable idle. But Jerry has a good point... oil pressure! If the oil pump isn't generating enough pressure, bad. I don't have a tach. I do have a tach I use on my chainsaw, which is triggered by induction (a lead wraps the spark plug wire). But I might just go by ear. 1. I never let it sit idling for more than a minute and don't mind letting it run HIGHER than normal while sitting/warming up for better oil pressure. 2. Then, I will set it for lower rpm for when I am actually riding it. It generally doesn't sit idling for more than a few moments during a ride. I always adjust the idle when I ride it, first to elevate the idle during a brief warmup, and then to set the idle once warm (warm enough).
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