Hpi savage 21 (hpi nitro star .21 engine) (3.5

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Nitrodannyboy

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So i traded my traxxas slayer for a really nice older savage21 with the hpi nitro star 21 engine. When i got home i put in a glow plug from my traxxas trx 3.3 engine. It sounded like the piston was wrapping on the glow plug. I had to remove it and add more copper washers. I know that's not right. You only should use 1 copper washer as a sealing tool correct? What plug do i need for that paticular engine? And are there different thread lengths so
that doesn't happen?
 
It seems HPI ships them with R5 plugs installed. I have a
header_image.jpg

But I haven't had to change the plug yet.
http://www.hpiracing.com/en/part/1504

It looks like they put an R5 in all their engines.
 
francis Labarbara said:
Any time.
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Great news after disassembling the carburetor cleaning and putting it back together at factory settings and then tuning my tactic transmitter to the truck it runs excellent but I'm having a problem hearing it shift into second I can't hear it shift I tried to adjust it counterclockwise and I still cannot hear a shift is it too far counterclockwise and shifting incredibly too early? Or is it not far enough?
 
I don't hear mine shift anymore. I don't know any way to tell either. It has a new transmission in it too. I am still trying to adjust it. You will only likley hear it running on pavement or short grass in a straight acceleration.
 
Well it runs great but I'm a little worried that ours not blowing enough smoke trail. It's a light trail I've tried factory settings and leading hi and low. Does the savage 21 blow a light smoke trail?
 
I use the Traxxas 20% Nitro fuel it seems like my Traxxas Slayer left a heavier smoke Trail but it might just be in my head I mean obviously this engine is getting lubrication because I would have blew it up and when I took the glow plug out it looks like the top of piston was well lubricated
 
Nitrodannyboy said:
Thankyou you were a big help
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Can you over tighten the low speed needle and cause damage on the 3.5 big block savage or does that just open up the midrange needle on the other side and cause me to have to retune the motor again from factory settings? what happened was I went to go put all of the settings back to factory on the carburetor to retune it After sitting and went to close it all the way and it just kept going in but i noticed the mid range was out further?! And when I adjust my transmission to the throttle servo does the needle come all the way out of the jet inside the carburetor
 
Nitrodannyboy said:
Can you over tighten the low speed needle and cause damage on the 3.5 big block savage or does that just open up the midrange needle on the other side and cause me to have to retune the motor again from factory settings? what happened was I went to go put all of the settings back to factory on the carburetor to retune it After sitting and went to close it all the way and it just kept going in but i noticed the mid range was out further?! And when I adjust my transmission to the throttle servo does the needle come all the way out of the jet inside the carburetor
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I meant to say transmitter not transmission because bullet Full Throttle in the middle all the way out of the jet in the carburetor when I'm looking into it
 
Clear pics would help alot here and maybe a bit better explanation of the problem also......

I would like to give you an answer but I am lost as to your problem.
 
I have never run your engine. Try reading this.
http://www.hpiracing.com/assets/documents/instruction_manuals/111603-f35_v2-glb-m-v1.pdf
The needles are set to flush with the body of the carb for stock settings. I am not sure which one you mean. There is no mid range needle. The low speed needle can back the slide out as you turn it in and never really bottom out. That is why it isnt set that way. The Idle screw is used to set the idle gap.
Yes you can damage the needles by turning them in forcefully.
Look at section 6 on page 5 of the PDF. It shows the stock settings of the needles in the carb body. They are not set by some number of turns from closed.
 
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francis Labarbara said:
I don't hear mine shift anymore. I don't know any way to tell either. It has a new transmission in it too. I am still trying to adjust it. You will only likley hear it running on pavement or short grass in a straight acceleration.
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So my savage 21 (3.5 bb) is def. Not sitting into second.
 
So my Savage 21 is definitely not shifting into 2nd gear. what are the common reasons for the sticky primary clutch? I thought maybe if I drove it around it would have loosened it up, but no such luck. lol. Maybe I would be able to get it to activate but it's not I also tried to adjust it but only the bottom set screw. What is the set screw above it on the primary clutch? Should I pull the transmission off, open it up and clean and lubricate everything and inspect?
 
Nitrodannyboy said:
So my Savage 21 is definitely not shifting into 2nd gear. what are the common reasons for the sticky primary clutch? I thought maybe if I drove it around it would have loosened it up, but no such luck. lol. Maybe I would be able to get it to activate but it's not I also tried to adjust it but only the bottom set screw. What is the set screw above it on the primary clutch? Should I pull the transmission off, open it up and clean and lubricate everything and inspect?
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the second setscrew holds the clutch hub on the shaft... and you sure can open it up and see if the clutch is sticking if you are comfortable doing so....

https://www.hpiracing.com/assets/documents/instruction_manuals/12881_savage_35_glb_m_v1.pdf

Look on page 18 of the manual and it details the 2 speed adjusting... I recommend starting with the screw backed out about 1 turn or so and adjusting from there until you hear the shift happen..... that adjusting setscrew is really short and it is easy to back it out too far and miss the point where it will shift.... also keep in mind the truck may not shift at all if the :ercm: is not running just right also so having it close to correct mixture settings will help alot...
 
Jam Racing 1 said:
the second setscrew holds the clutch hub on the shaft... and you sure can open it up and see if the clutch is sticking if you are comfortable doing so....

https://www.hpiracing.com/assets/documents/instruction_manuals/12881_savage_35_glb_m_v1.pdf

Look on page 18 of the manual and it details the 2 speed adjusting... I recommend starting with the screw backed out about 1 turn or so and adjusting from there until you hear the shift happen..... that adjusting setscrew is really short and it is easy to back it out too far and miss the point where it will shift.... also keep in mind the truck may not shift at all if the :ercm: is not running just right also so having it close to correct mixture settings will help alot...
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Yes I'm pretty familiar with nitro and how they work. I'm also pretty confident in my tuning capabilities. Even leaning it out to optimum performance will not shift I've backed it out pretty far i don't want to go any further in fear that i may drop it in the gear box (the set screw). Can those clutches become sticky and not want to engage? And if so can i "rebuild" it? or clean and lubricate?
 
Like I said above start by setting the shift point a turn or so out from bottomed and go from there with adjusting, it does sound like you have the screw backed out a bit far so I would do that first....

you can get a new shift hub or attempt to clean the one you already have... it is a fairly simple centrifugal type setup with a shoe, ball and spring setup held buy the setscrew so I would at least check it out...
 
Nitrodannyboy said:
Can i use wd 40 and spray a small amount through the adjustment hole ontp the primary clutch to try and loosen it?
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Jam Racing 1 said:
Like I said above start by setting the shift point a turn or so out from bottomed and go from there with adjusting, it does sound like you have the screw backed out a bit far so I would do that first....

you can get a new shift hub or attempt to clean the one you already have... it is a fairly simple centrifugal type setup with a shoe, ball and spring setup held buy the setscrew so I would at least check it out...
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the hub is not open enuff to allow what you are wanting to do. start by resetting as stated above first.....
 
I removed the gear box and disassembled to clean. and the primary clutch was gunked up so i removed the set screw and spring, along with bearing, and cleaned well. now it shifts excellent. Thank you all for your advice and wisdom. Major help
 
Okay so my two-year-old son pushed my truck off the table and it landed upside down and broke the top fin on the cooling head. for now cam i just cut the rest of that top fin off? With a hack saw,
It may just run a little hotter correct? If at all. It's a huge cooling head!
 
I have a mach .26 engine. (Dynamite) can i bolt right in to my savage .21? Can i use my clutch bell and components off my nitro star .21 big block? And if not what do i need.
 
Nitrodannyboy said:
I have a mach .26 engine. (Dynamite) can i bolt right in to my savage .21? Can i use my clutch bell and components off my nitro star .21 big block? And if not what do i need.
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Most any big block :ercm: can be fitted. use your flywheel and clutch assembly and bolt it in......
 
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