XJman's Rovan 5b build

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.
X

XJman

Well-Known Member
Messages
245
Reaction score
103
I've got a 5b on the way. I decided on one of the cheaper 29cc ones. I don't know if I'll really like driving off road as I'm an on road guy so I went in affordably. I've got loctite ready to hit the screws Killswitch and better radio gear.

Anything I should be prepared to replace or should upgrade asap? I've seen a lot of ones online with some type of aluminum shock mounts, but not much else. What would you guys recommend?
 
Last edited:
Nut and bolt check, found couple loose ones on brand new baja terminator I just got. The flysky 3 Channel radio seems iffy to me so installed spare flysky gt5 and kill switch today. Other than that I would see what happens before upgrades. Couple 5 minutes idle heat cycles then beat the snotty out of it is my plan!!!! Never broke anything on my old baja 5sc trucks except shocks, they were plastic but this new one already has aluminum ones. Oh that and lower rear skid plate. Keep us updated as will I.
 
Mick Mars said:
Nut and bolt check, found couple loose ones on brand new baja terminator I just got. The flysky 3 Channel radio seems iffy to me so installed spare flysky gt5 and kill switch today. Other than that I would see what happens before upgrades. Couple 5 minutes idle heat cycles then beat the snotty out of it is my plan!!!! Never broke anything on my old baja 5sc trucks except shocks, they were plastic but this new one already has aluminum ones. Oh that and lower rear skid plate. Keep us updated as will I.
Click to expand...
Should update the first post but I've got a kill switch and I'm probably going to use my noble for it.

I expect a 500 dollar 1/5 scale. Im not familiar with the lower skid plate? The part I the back that holds the lower body?
 
Alright. Someone prove to me the stock engine isn't bunk. Its not a huge deal as I have other engines sitting around but this damn thing will not start.

I have spark. I have fuel.

Needle settings 1/14 low 1 1/2 high. Compression feels ok. It is nowhere near my zenoahs but it isn't nothing. Similar to an old CY 26 I have that I know was solid when I retired it.
 
Choke on till it pops.Open choke ,no more than 4 or 5 pulls should start. Don't just keep pulling or will flood. Mine is a rovan36 ,literally brand new. First time I primed bulb till fuel line solid, no bubbles. Closed choke,popped 2nd pull. Opened choke fired 3rd pull and idled perfect. I have been doing this with everything I have 2 stroke and never fail to start. If it's taking more than 6 pulls I will pull plug and check if they are flooding. Very rare for me..... Usually only happens 1 or 2 times a year and I will install fresh plug and Usually solves it. You running the cmr7h , I think that's the numbers, mine came with that plug.
 
Yeah no go. I'm getting fuel. Got spark. Choke or no choke i can't get it to pop.
 
Did you install kill switch yet..... no bubbles when priming bulb, as in yellow line. Maybe pull tank plug and pump bulb to check flow. If that's OK I would change plug. Has it ran at all yet or is this first start ? Asking about kill switch to make sure you are """ setting """ it to run........ Maybe reset carb, try 1 3/4 low and 2 high, back idle screw out then turn it till just barely moves throttle arm. Check east side rc on you tube, really good and has several videos on carb tunes and basic setups
 
Last edited:
First start.

I've tried with and without a kill switch. primed with no air bubbles. with and with out air filter. I tried a known good plug and same.

I'm 100% getting fuel and the fuel flows fine. I'm starting to think its the compression.

What carb settings are you using? what I said earlier is what I have in my notebook and it matched what the carb was tuned from rovan.
 
I'm pretty baffled???? It won't pop at all .... red weak spark, or bright wight blueish spark? Sometimes got to pull plug and turn car over to drain any excess fuel and start from beginning. Is plug wet? Don't want to make things worse for you.... Last thing I would do is remove pull start cover and check coil wires and coil gap to flywheel. Should be about thickness of business card or tad less. Last resort call rovan....... I haven't touched carb yet, still breaking in. Sometimes on my taylor 50 have to just barely crack throttle open after choke on, popped, choke off . But I do run very low idle speeds.
 
Its a full white ass spark.

Plug is getting wet but not soaked. I'm going to let it sit tonight and giver her the beans again tomorrow. If it still doesn't I'm going to tear it down further. The filter design on this damn thing is a pain in the ass.
 
Just ordered a new one from Detroit rc and complete set of outerwears, should be here tomorrow or Thursday. I'll post some pics on my happy birthday post . Sorry it's not going so good but you'll get it going.
 
Mick Mars said:
Just ordered a new one from Detroit rc and complete set of outerwears, should be here tomorrow or Thursday. I'll post some pics on my happy birthday post . Sorry it's not going so good but you'll get it going.
Click to expand...
I will. I honestly expected this thing to be way rougher than it is. The fit and finish is actually pretty good and the body parts are cut cleaner than some of the horizon hobbies vehicles I've bought
 
What did you find that was causing the issue. Started installing my outerwears today, found a busted off lower rear shock bolt....just going to let it go for now but got all 4 shocks done.
 
Mick Mars said:
What did you find that was causing the issue. Started installing my outerwears today, found a busted off lower rear shock bolt....just going to let it go for now but got all 4 shocks done.
Click to expand...
Only thing I can figure is the piston or the ring. It's got some wear on the side of the piston that's surprising for something that didnt ever run.

I literally did a frame in piston swap, put the can back on walked outside and cranked to an immediate fire without the choke at all.

I'll get a photo of the piston later.
 
Mick Mars said:
Wow I think you nailed it on the lack of compression. Glad you figured things out !!!!!
Click to expand...
Here are the piston photos. I don't like this carb so it might go. My big focus right now is trying to get a stable tune that's not so rich it's burning fuel like crazy.


The first photo has a massive gouge on the intake side. I took a ceramic stone and softened anything sharp near the ports so hopefully the cylinder holds up.
 

Attachments

  • 20250920_173352.webp
    20250920_173352.webp
    74.5 KB · Views: 10
  • 20250920_173358.webp
    20250920_173358.webp
    74.7 KB · Views: 8
  • 20250920_173404.webp
    20250920_173404.webp
    82.6 KB · Views: 8
This was new from what I gather?
Give Rovan a call and talk to them. Their customer service was very good to me. Phone seems to work better than email so don't be afraid to call. They might want a picture but obviously you have that. Might be able to get them to send a new piston and cylinder.
 
smokinwheel said:
This was new from what I gather?
Give Rovan a call and talk to them. Their customer service was very good to me. Phone seems to work better than email so don't be afraid to call. They might want a picture but obviously you have that. Might be able to get them to send a new piston and cylinder.
Click to expand...
I got this from a dude locally who orders them in bulk and sells them.

It was 23 bucks I'm not going to harass them over it. I bought this thing cheap and I'm ok with it having some flaws. I'm actually impressed with the quality of everything else. It isn't my xr5 but it's equal to what I've picked up from arrma and losi lately.

I tuned it yesterday and it absofuckinglutely screams. I'm quite surprised with that motor. The carb is a little iffy but I got it to a point of stability. I ordered a new air filter and velocity stack because that factory design sucks and a silencer although I'm going to need a better pipe design. This long ass thing will be at risk with the silencer on it.

What can people tell me about the symmetrical steering kit for them? I've heard people say it makes all the difference in it's cornering
 
Back
Top