Boom 125cc not starting

Hirales · 08-11-2020, 08:41 PM

hello i just bought a new boom 125cc from red fox motorsports and I've had issues from the moment I got it but the biggest one being is the bike wont stay started it will start then die then its a bitch to get it started again im hoping someone has some insight on this and would be able to help me figure out what is going on ive tried calling the place where I bought it but its like pulling teeth for them to answer and when they do they either hang up on me or say they don't know anything altho they are sending out a battery because the original one had a dead cell in it but I changed that out and it still does the same thing if someone has been through what I'm going through and can help me it would be much appreciated thank you

Darryl · 08-11-2020, 08:56 PM

Pull your fuel lines off the carb and verify you are getting fuel. Pull the plug and verify there is a spark when cranking. Gap the plug at .028" and put it back in. I had the same issue and these steps for it running in minutes. These engines seem pretty sensitive with that spark gap.

Hirales · 08-11-2020, 09:18 PM

Ok i haven't pulled the fuel lines off but I did check to make sure I had a spark had spark and it did i pulled it off and put it on the engine while I cranked it. What do you mean by gap the plug .028" like screw it in there that much or take it out that much? I will definitely go check the fuel lines tho

f15sim · 08-12-2020, 01:49 PM

I would strongly suggest you google "how to set the gap on a spark plug". Seriously - it's something you need to know how to do. You'll need a spark gap gauge as well.

You should be able to find something like this https://www.amazon.com/CTA-Tools-323.../dp/B00144AZ6K at your local auto parts store.

g.

Hirales · 08-12-2020, 01:56 PM

Quote:

Originally Posted by f15sim

I would strongly suggest you google "how to set the gap on a spark plug". Seriously - it's something you need to know how to do. You'll need a spark gap gauge as well.

You should be able to find something like this https://www.amazon.com/CTA-Tools-323.../dp/B00144AZ6K at your local auto parts store.

g.

Ok thank you so much do you think that could be the problem

tortoise · 08-12-2020, 02:15 PM

Quote:

Originally Posted by Hirales

bought a new boom 125cc from red fox motorsports

BD125-10, Groom 125cc?

f15sim · 08-12-2020, 03:00 PM

Quote:

Originally Posted by Hirales

Ok thank you so much do you think that could be the problem

I have no idea. It could be a contributor, but I don't know. My knowledge of internal combustion engines can fill the inside half of a matchbook if you use big letters.

g.

Hirales · 08-12-2020, 03:04 PM

Quote:

Originally Posted by tortoise

BD125-10, Groom 125cc?

Yes it is a boom 125cc/ bd125-10 gen 2

Darryl · 08-12-2020, 04:37 PM

I have two of them that I bought from RFPS in June. One fired right up, one required pulling a vacuum on the fuel line to get it flowing as well as a properly tapped plug.

My wife found out that they will foul plugs if you leave the choke on for too long. It's an easy fix, but it showed how sensitive they are with spark plugs.

Plan on spending some You-tube time if you are going to ride these Chinese bikes. You will either be mechanically adept or you will get a lot of walking time. They are simple to work on, but they will require some work. Pre trip them regularly before riding to keep ahead of any problems.

culcune · 08-13-2020, 03:40 PM

Quote:

Originally Posted by Darryl

I have two of them that I bought from RFPS in June. One fired right up, one required pulling a vacuum on the fuel line to get it flowing as well as a properly tapped plug.

Do these bikes come with their valve lash adjusted? That has been an issue with some of the vertical thumpers in the full-size dual-sports and street bikes--the valves have come way too tight and need adjusting out of the box.

Drewilious · 08-31-2021, 10:41 PM

If you haven't, there's a fuel tank vent line that goes down the left side of the tank. Remove the check valve.

Here's what it looks like.

TyGuy · 09-01-2021, 07:38 AM

Have you adjusted your idle screw? Your bike has the same type of carb setup as mine (x22). When mine arrived, it definitely required some carb tuning to idle correctly. These carbs have a single screw. May be something to look at. I have mine set to idle at just over 1500 RPMs. You can turn it with your fingers or screwdriver. Adjust in small increments.

08-11-2020, 08:41 PM	#1
Hirales Join Date: Aug 2020 Posts: 14	Boom 125cc not starting hello i just bought a new boom 125cc from red fox motorsports and I've had issues from the moment I got it but the biggest one being is the bike wont stay started it will start then die then its a bitch to get it started again im hoping someone has some insight on this and would be able to help me figure out what is going on ive tried calling the place where I bought it but its like pulling teeth for them to answer and when they do they either hang up on me or say they don't know anything altho they are sending out a battery because the original one had a dead cell in it but I changed that out and it still does the same thing if someone has been through what I'm going through and can help me it would be much appreciated thank you
	0

08-12-2020, 01:49 PM	#4
f15sim Join Date: May 2020 Location: Graham, WA Posts: 118	I would strongly suggest you google "how to set the gap on a spark plug". Seriously - it's something you need to know how to do. You'll need a spark gap gauge as well. You should be able to find something like this https://www.amazon.com/CTA-Tools-323.../dp/B00144AZ6K at your local auto parts store. g. __________________ Proud owner of 80-0007. https://www.f15sim.com - The only one of its kind.
	0

09-01-2021, 07:38 AM	#12
TyGuy Join Date: Jun 2021 Location: New Jersey Posts: 112	Have you adjusted your idle screw? Your bike has the same type of carb setup as mine (x22). When mine arrived, it definitely required some carb tuning to idle correctly. These carbs have a single screw. May be something to look at. I have mine set to idle at just over 1500 RPMs. You can turn it with your fingers or screwdriver. Adjust in small increments. __________________ -2021 Venom X22-GT -2021 Venom X22 -1910 Flying Merkel Board Track Racer Replica (self-built) IG: @TyGuyProductions
	0

08-11-2020, 08:56 PM	#2
Darryl Join Date: May 2020 Posts: 13	Pull your fuel lines off the carb and verify you are getting fuel. Pull the plug and verify there is a spark when cranking. Gap the plug at .028" and put it back in. I had the same issue and these steps for it running in minutes. These engines seem pretty sensitive with that spark gap.
	0

08-11-2020, 09:18 PM	#3
Hirales Join Date: Aug 2020 Posts: 14	Ok i haven't pulled the fuel lines off but I did check to make sure I had a spark had spark and it did i pulled it off and put it on the engine while I cranked it. What do you mean by gap the plug .028" like screw it in there that much or take it out that much? I will definitely go check the fuel lines tho
	0

08-12-2020, 04:37 PM	#9
Darryl Join Date: May 2020 Posts: 13	I have two of them that I bought from RFPS in June. One fired right up, one required pulling a vacuum on the fuel line to get it flowing as well as a properly tapped plug. My wife found out that they will foul plugs if you leave the choke on for too long. It's an easy fix, but it showed how sensitive they are with spark plugs. Plan on spending some You-tube time if you are going to ride these Chinese bikes. You will either be mechanically adept or you will get a lot of walking time. They are simple to work on, but they will require some work. Pre trip them regularly before riding to keep ahead of any problems.
	0