Bought a HPI Baja 5B and have questions - Please help.

[kashif]

Hi Guys,

Trust you will be fine. This is my first post apart from the introduction forum. I am not new to RC but new to Large Scale Petrol vehicles. All this time I only played with Electric 1:10 or 1:8 scales. The sound and smoke of Nitro and Gasoline vehicles always fascinates me but I was hesitant because of the troubles of tuning and taking care as I don't know anything about such vehicles.

Finally, I decided to go for it and instead of going for Nitro I went for Gasoline and since I don't have long pockets so I bought a used HPI Baja 5B from a reputable Hobby Shop dealer whom I know from a long time and have complete trust that he will sell me the original Baja and not the clone.

The car has some upgrades installed by the previous owner like shock covers, few aluminum parts inside. But most importantly as per the shop keeper there is a 29 cc head piston installed and also a tuned pipe. Like I said I am new to these cars so I don't know what is the significance of these parts. Here are a couple of questions:

1) The shop keeper says that these upgrades make my Baja 5B 29 cc and not 23 cc. Is he correct? Please note the engine is stock 23 cc and its just the head piston which is 29 cc.

2) Can you please identify this installed tuned pipe and please tell me the importance of having a tuned pipe?




3) My Baja always starts after like three or four tries and never in the first or second try. Is this normal?

4) Now this happens sometimes that after I start the engine it stops automatically after like 2 or 3 minutes and this happens specially when I give throttle a little push only. But when I go like full throttle or middle throttle it stays fine but it stops if I give throttle a tiny push in the beginning. What causes this?

5) I have a temp gun so can you please tell me what is the accepted temperature of engine. Its always hot as hell in this part of the world. So please tell me what is the accepted and alarming engine temp readings?

I have few other questions too but this post is getting too long. I ll ask those questions later. Kindly please reply to my questions.

Here are some other pictures of the car:












Thanks a lot.

 

[atom3624]

Nice photos!
All HPI Bajas started on 23 or 26cc CY / Fuelie engines depending on model.
EVERYBODY modifies their 'ride' so unless it's been purchased and sat on a shelf since purchase, then it is highly likely the 29 (probably 28.5cc) is correct.
What is the typical ambient temperature where you are going to run it, and what are you going to run it on - tarmac, grass, sand?
These should all be considered when looking at 'operating temperatures', as well as how wide open the throttle is.
Considering where you are, the mixing ratio is important - keep it well lubricated. 90% go for 25 petrol:1 oil - and no higher than 32:1. You will read stories of 40:1 and even 50:1, but DON'T DO IT - these are for strimmers, hedge cutters, etc., which rev lower than 'our motors'.
Is the failsafe set up properly? This will set the brakes and steering in the event that the battery is still connected, but the radio signal is lost.
Does it have a remote kill switch? This will cut the motor in the event of battery failure and/or radio signal loss.

Al.

 

[quentrm250]

Pipe looks like a Dominator v1 but it's hard to tell since the forum shrinks the pictures. A properly tuned pipe such as the Dom helps to scavenge the exhaust out of the engine and suck in a fresh charge of fuel/air. It does a much better job than the factory square muffler and will increase power. Just the pipe alone in used condition is around $100.

Go to NAPA or similar stores and get a new exact replacement spark plug and try that first. If that doesn't work tune the carb. Go to youtube and google how to tune a baja 5b carb and tune accordingly. The right screw on the carb is low rpm air/fuel mixture and the left is Hi. Slowly turn both screws in until they stop (do not overtighten). Back the right screw out 1 1/4 turns and the left 1 1/2 turns. Adjust in tiny increments from there with the car on a block. Lo first and then Hi. Set the idle last.

Welcome to the addiction!

 

[kashif]

Nice photos!
All HPI Bajas started on 23 or 26cc CY / Fuelie engines depending on model.
EVERYBODY modifies their 'ride' so unless it's been purchased and sat on a shelf since purchase, then it is highly likely the 29 (probably 28.5cc) is correct.
What is the typical ambient temperature where you are going to run it, and what are you going to run it on - tarmac, grass, sand?
These should all be considered when looking at 'operating temperatures', as well as how wide open the throttle is.
Considering where you are, the mixing ratio is important - keep it well lubricated. 90% go for 25 petrol:1 oil - and no higher than 32:1. You will read stories of 40:1 and even 50:1, but DON'T DO IT - these are for strimmers, hedge cutters, etc., which rev lower than 'our motors'.
Is the failsafe set up properly? This will set the brakes and steering in the event that the battery is still connected, but the radio signal is lost.
Does it have a remote kill switch? This will cut the motor in the event of battery failure and/or radio signal loss.

Al.

Pipe looks like a Dominator v1 but it's hard to tell since the forum shrinks the pictures. A properly tuned pipe such as the Dom helps to scavenge the exhaust out of the engine and suck in a fresh charge of fuel/air. It does a much better job than the factory square muffler and will increase power. Just the pipe alone in used condition is around $100.

Go to NAPA or similar stores and get a new exact replacement spark plug and try that first. If that doesn't work tune the carb. Go to youtube and google how to tune a baja 5b carb and tune accordingly. The right screw on the carb is low rpm air/fuel mixture and the left is Hi. Slowly turn both screws in until they stop (do not overtighten). Back the right screw out 1 1/4 turns and the left 1 1/2 turns. Adjust in tiny increments from there with the car on a block. Lo first and then Hi. Set the idle last.

Welcome to the addiction!

Thanks a lot for the detailed replies and information. Like I said I am new so please excuse me but I need to ask that by Carb do you mean "carburettor"? Also someone on another forum told me that my pipe is a clone to ddm dominator so I am in doubt that if its the real one or a clone but I want to know if its a clone are those clone pipes good?

Its 45 to 47 Celsius (113 to 116 Fahrenheit) but I always drive at late night when the things are cool. Since its surrounded by desert so the sand cools at night make the temperature tolerable. I drive on road mainly and also off road sometimes so on tarmac and sand. No grass. Do I have to install the kill switch or is it already installed by HPI in Bajas? I do have the option in my transmitter but don't know how to use it?

I never tuned a car before but I ll try to do it. How about re adjust them to Factory settings? I watched a video by HPI and they say that you should do very fine or subtle tuning otherwise it may harm the engine.

I also want to ask another thing that the hobby shop guy told me to make a solution as 5 liter of Petrol and 200 ml of oil and mix them together to use. Is he correct on this? Please also tell me that is it true that you don't need to use petrol and oil which has been mixed for a month? I saw this tip in a video by HPI. I don't drive my vehicle everyday so I need to know the exact combination for oil and Petrol so I can mix them in small scales.

Please Help. Thanks!

 

[quentrm250]

Thanks a lot for the detailed replies and information. Like I said I am new so please excuse me but I need to ask that by Carb do you mean "carburettor"? Also someone on another forum told me that my pipe is a clone to ddm dominator so I am in doubt that if its the real one or a clone but I want to know if its a clone are those clone pipes good?

Its 45 to 47 Celsius (113 to 116 Fahrenheit) but I always drive at late night when the things are cool. Since its surrounded by desert so the sand cools at night make the temperature tolerable. I drive on road mainly and also off road sometimes so on tarmac and sand. No grass. Do I have to install the kill switch or is it already installed by HPI in Bajas? I do have the option in my transmitter but don't know how to use it?

I never tuned a car before but I ll try to do it. How about re adjust them to Factory settings? I watched a video by HPI and they say that you should do very fine or subtle tuning otherwise it may harm the engine.

I also want to ask another thing that the hobby shop guy told me to make a solution as 5 liter of Petrol and 200 ml of oil and mix them together to use. Is he correct on this? Please also tell me that is it true that you don't need to use petrol and oil which has been mixed for a month? I saw this tip in a video by HPI. I don't drive my vehicle everyday so I need to know the exact combination for oil and Petrol so I can mix them in small scales.

Please Help. Thanks!

Yes, carb=carburetor.
Stick with 25 parts gas to 1 part oil. 2500ml to 100ml and such.
Perol and oil mix will be fine in a good sealed gas can for a month or two. Do not use Ethanol blend gasoline

 

[kashif]

Yes, carb=carburetor.
Stick with 25 parts gas to 1 part oil. 2500ml to 100ml and such.
Perol and oil mix will be fine in a good sealed gas can for a month or two. Do not use Ethanol blend gasoline

Thanks a lot.

 

[kashif]

Its 45 to 47 Celsius (113 to 116 Fahrenheit) but I always drive at late night when the things are cool. Since its surrounded by desert so the sand cools at night make the temperature tolerable. I drive on road mainly and also off road sometimes so on tarmac and sand. No grass. Do I have to install the kill switch or is it already installed by HPI in Bajas? I do have the option in my transmitter but don't know how to use it?

I never tuned a car before but I ll try to do it. How about re adjust them to Factory settings? I watched a video by HPI and they say that you should do very fine or subtle tuning otherwise it may harm the engine.

I also want to ask another thing that the hobby shop guy told me to make a solution as 5 liter of Petrol and 200 ml of oil and mix them together to use. Is he correct on this? Please also tell me that is it true that you don't need to use petrol and oil which has been mixed for a month? I saw this tip in a video by HPI. I don't drive my vehicle everyday so I need to know the exact combination for oil and Petrol so I can mix them in small scales.

Please Help. Thanks!