harder to start....

[skiracer]

I re-did the top end on my 175 XC, and I replaced the Mikuni with a new one. The bike use to start on the second kick when it was cold, and 1/2 a kick when it was warm.  Now it takes 7 or 8 kicks when it is cold, and at least 4 when it is warm.   I am running a 22.5 pilot jet and thinking of going down to a 20 to see if that helps.  Any thoughts why the change?

1976 MC 5 Original Owner
1982 Suzuki PE 175
1976 Penton 175 XC
1985 20' Hi Point trailer

[454MRW]

That sounds like a lean condition to me. You may need to go up on jet sizes,not down. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1978-1979 MX-6 175 & 250 KTM's
1976-78 125-400 RM's & 79 PE250 Suzuki & 2012 DR650
2007 CR125R Honda
1977 MC250 Maico

[skiracer]

Thanks for the input Mike!

quote:Originally posted by 454MRW

That sounds like a lean condition to me. You may need to go up on jet sizes,not down. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1978-1979 MX-6 175 & 250 KTM's
1976-78 125-400 RM's & 79 PE250 Suzuki & 2012 DR650
2007 CR125R Honda
1977 MC250 Maico

1976 MC 5 Original Owner
1982 Suzuki PE 175
1976 Penton 175 XC
1985 20' Hi Point trailer

[brian kirby]

That is extremely lean, I would not use smaller than a 35 pilot jet.

Brian

[skiracer]

Well I went from the 22.5 to a 25 and the needle clip is in the middle.  The bike is running really rich on the bottom.  When I turn the throttle off the idle, and it is almost loading up; way too rich.

1976 MC 5 Original Owner
1982 Suzuki PE 175
1976 Penton 175 XC
1985 20' Hi Point trailer

[Steve Minor]

One time I reassembled my carb with the needle and clip inside the plastic cup rather than under it. It ran super rich and took me a while to figure it out. Any chance you did that?

Steve Minor

[skiracer]

Steve, I don't understand your comment.  What is the plastic cup?  Anyway, I went to a 20 pilot jet and it rums much better.  I think I need to adjust the clip on the needle for some fine tuning...  Thanks for your input, well appreciated.

quote:Originally posted by Steve Minor

One time I reassembled my carb with the needle and clip inside the plastic cup rather than under it. It ran super rich and took me a while to figure it out. Any chance you did that?

Steve Minor

1976 MC 5 Original Owner
1982 Suzuki PE 175
1976 Penton 175 XC
1985 20' Hi Point trailer

[Steve Minor]

Sorry....I should have read your first post more carefully. I just assumed you were using a Bing, not a Mikuni. Bings have a white plastic cup that the return spring sits in. It's sometimes easy to drop the needle and clip inside the cup rather than under the cup.

Steve Minor

[brian kirby]

quote:Originally posted by skiracer

Well I went from the 22.5 to a 25 and the needle clip is in the middle.  The bike is running really rich on the bottom.  When I turn the throttle off the idle, and it is almost loading up; way too rich.

The range you are describing is not controlled by the pilot jet, it is controlled by the needle jet and the slide cutaway. On a Mikuni the pilot jet only controls idle when the slide is shut. What size Mikuni? Sounds like your needle jet is too rich, what needle jet is in it? I have Husky, Can-Am, Yamaha, and Penton 175s and the smallest pilot in any of those bikes is a 35, a 22.5 or even 25 pilot is really unusual, but as I always say, dont get hung up on the number and give the engine whatever jet size makes it happy.

Brian

[skiracer]

Hey Brian,
The carb is a 34mm. I don't have any notes on the needle jet.  I have never changed on before.  Ii will take a look at it on Tuesday.  Thanks for your input, it is well appreciated....

quote:Originally posted by brian kirby

quote:Originally posted by skiracer

Well I went from the 22.5 to a 25 and the needle clip is in the middle.  The bike is running really rich on the bottom.  When I turn the throttle off the idle, and it is almost loading up; way too rich.

The range you are describing is not controlled by the pilot jet, it is controlled by the needle jet and the slide cutaway. On a Mikuni the pilot jet only controls idle when the slide is shut. What size Mikuni? Sounds like your needle jet is too rich, what needle jet is in it? I have Husky, Can-Am, Yamaha, and Penton 175s and the smallest pilot in any of those bikes is a 35, a 22.5 or even 25 pilot is really unusual, but as I always say, dont get hung up on the number and give the engine whatever jet size makes it happy.

Brian

1976 MC 5 Original Owner
1982 Suzuki PE 175
1976 Penton 175 XC
1985 20' Hi Point trailer

[skiracer]

Spoke too soon.  I have more notes than I thought...  The needle is a 6D4H......

quote:Originally posted by skiracer

Hey Brian,
The carb is a 34mm. I don't have any notes on the needle jet.  I have never changed on before.  Ii will take a look at it on Tuesday.  Thanks for your input, it is well appreciated....

quote:Originally posted by brian kirby

quote:Originally posted by skiracer

Well I went from the 22.5 to a 25 and the needle clip is in the middle.  The bike is running really rich on the bottom.  When I turn the throttle off the idle, and it is almost loading up; way too rich.

The range you are describing is not controlled by the pilot jet, it is controlled by the needle jet and the slide cutaway. On a Mikuni the pilot jet only controls idle when the slide is shut. What size Mikuni? Sounds like your needle jet is too rich, what needle jet is in it? I have Husky, Can-Am, Yamaha, and Penton 175s and the smallest pilot in any of those bikes is a 35, a 22.5 or even 25 pilot is really unusual, but as I always say, dont get hung up on the number and give the engine whatever jet size makes it happy.

Brian

1976 MC 5 Original Owner
1982 Suzuki PE 175
1976 Penton 175 XC
1985 20' Hi Point trailer

1976 MC 5 Original Owner
1982 Suzuki PE 175
1976 Penton 175 XC
1985 20' Hi Point trailer

[brian kirby]

When I took the Bing off of my Can-Am 175 I put the standard generic Mikuni 34mm, probably the same one you have, and I had to lean the needle jet several sizes. That stock needle jet was close for the '83 Husky 175WR and the '82 Husky 125XC, but I had to lean the needle jet on my '72 Jackpiner and Yamaha 175s, just not as much as the Can-Am. You should have a Q-2, I think I put a P-4 in the Can-Am and a Q-0 in the Penton. Have you tried the needle clip in the top (leanest) position? Try a richer pilot jet (25 or 30) and the clip in the leanest position. Each needle jet is the equivalent of moving the clip form the middle slot to the bottom or top depending on if its richer or leaner so that will give you a feel for how much change you need.

Brian

[skiracer]

Okay, it has a 159 Q-0.  I will try moving the clip from the middle to the top to lean it out, and I will go from the 20 to a 25 pilot.  Thanks for all your help and knowledge....

quote:Originally posted by brian kirby

When I took the Bing off of my Can-Am 175 I put the standard generic Mikuni 34mm, probably the same one you have, and I had to lean the needle jet several sizes. That stock needle jet was close for the '83 Husky 175WR and the '82 Husky 125XC, but I had to lean the needle jet on my '72 Jackpiner and Yamaha 175s, just not as much as the Can-Am. You should have a Q-2, I think I put a P-4 in the Can-Am and a Q-0 in the Penton. Have you tried the needle clip in the top (leanest) position? Try a richer pilot jet (25 or 30) and the clip in the leanest position. Each needle jet is the equivalent of moving the clip form the middle slot to the bottom or top depending on if its richer or leaner so that will give you a feel for how much change you need.

Brian

1976 MC 5 Original Owner
1982 Suzuki PE 175
1976 Penton 175 XC
1985 20' Hi Point trailer

[tomale]

Moving the clip only changes the timing of when you get fuel, if it is too lean or too rich from just of idle to mid throttle then the needle jet is where you need to look. Moving the needle may give you a clue as to what needs to change but once you change the size of the needle jet, put the needle back on the center clip. All of my bikes are set for sea level so if I ride above 2500 feet, I will sometimes change out the pilot and drop the needle one step.

Thom Green,Still crazy after all these years!
74' 1/2 440 maico
70' 400 maico (project)
93' RMx 250 suzuki
2004 Suzuki DL1000
1988 Honda Gl 1500
2009 KTM 400 XC-W

[brian kirby]

Thom is correct, you need to move the clip back to the middle when you change the needle jet, but by going to the leanest clip slot and a richer pilot it will tell you if that is the right direction to go further before you buy any jets. I am pretty sure that a richer pilot and a leaner on the needle jet is the right direction.

Brian