EB Mods JS Engine
03-15-2011 | 03:06 PM
#1726
I bought a new .21 race prep to use in my buggy at last week's Psycho Nitro Blast and struggled with getting a decent tune with it all 4 days. Granted it was brand new when I got to the race, but I ran through 2 tanks on my starter box, then ran 3 tanks very conservatively on the track in my buggy. It ran fine when I was putting around the track, but when I started to get on the throttle after running the 5 first tanks, I couldn't get it to tune. (Running Byrons 30% and OD 97T plugs) I leaned it an hour on top from the box stock settings and it ran OK, then after a few more tanks, I leaned it another hour to start to work on my race tune, but it still wouldn't clear out on top. I tried several pipes - 086, 2039, 2050 and 9901, but it still wouldn't produce much top end. I tried leaning it out 1, then 2 hours more, with each of the pipes, but then I started to lean bog. Needless to say, it wasn't easy to run competitively during qualifying. (Lean bogging right before the huge triple made me come up way short several times and I broke an a-arm in 1 qual.)
Any advice on what I'm doing wrong or what I need to do to get this engine to run? I'm not going to give up on it yet, but the engine was definitely NOT ready for a race tune right out of the box!
Any advice on what I'm doing wrong or what I need to do to get this engine to run? I'm not going to give up on it yet, but the engine was definitely NOT ready for a race tune right out of the box!
03-15-2011 | 03:39 PM
#1727
im very new to this js engine, actually have yet to get mine. but after talking with a lot of people they all told me to not run odonnel plugs, use os p4 or colder. also shocker several post back said the 2081 is the pipe that works the best on this engine, and some pipes cause a weird hesitation......idk im just passing along info that ive recieved in this forum
03-15-2011 | 04:50 PM
#1728
Tech Addict
Joined: Aug 2003
Posts: 526
From: PA
I spoke to Ed on Wed before the race and he said the OD plugs would be fine. I tried a colder 99T plug too, but it was no help either. I won't use OS plugs anymore since a bad batch of them made me have to resleeve a vspec twice a few years ago because they dropped their filaments into cylinder witgin 10 minutes after installing them. Also, Ed recommendss the 086 pipe for this engine, so it has to be a tuning issue. Thx for the input though.
The issue you explained sounds exactly like the OD97T plug issue that I mentioned on the phone on Wednesday. Please see the attached pics and compare to your glow plug. Basically the top of the plug bottoms out on the head button and not at the seat area at the base of the glow plug stem. Blow-By around the plug reduces the engine compression at even more at peak pressure making it very hard to tune the top-end.
FYI I have spoke to Steve O'Donnell about this issue and it has been addressed. But it is still possible to get old stock which may have this issue.
Last edited by EBMods; 03-15-2011 at 05:04 PM.
03-15-2011 | 05:03 PM
#1729
Sorry to hear about the issues you had at PNB. I wish you would of called the shop or emailed me during the race. I'm sure we would of figured it out.
The issue you explained sounds exactly like the OD97T plug issue that I mentioned on the phone on Wednesday. Please see the attached pics and compare to your glow plug. Basically the top of the plug bottoms out on the head button and not at the seat area at the base of the glow plug stem.
FYI I have spoke to Steve O'Donnell about this issue and it has been addressed. But it is still possible to get old stock which may have this issue.
The issue you explained sounds exactly like the OD97T plug issue that I mentioned on the phone on Wednesday. Please see the attached pics and compare to your glow plug. Basically the top of the plug bottoms out on the head button and not at the seat area at the base of the glow plug stem.
FYI I have spoke to Steve O'Donnell about this issue and it has been addressed. But it is still possible to get old stock which may have this issue.
03-15-2011 | 05:35 PM
#1731
Sorry to hear about the issues you had at PNB. I wish you would of called the shop or emailed me during the race. I'm sure we would of figured it out.
The issue you explained sounds exactly like the OD97T plug issue that I mentioned on the phone on Wednesday. Please see the attached pics and compare to your glow plug. Basically the top of the plug bottoms out on the head button and not at the seat area at the base of the glow plug stem. Blow-By around the plug reduces the engine compression at even more at peak pressure making it very hard to tune the top-end.
FYI I have spoke to Steve O'Donnell about this issue and it has been addressed. But it is still possible to get old stock which may have this issue.
The issue you explained sounds exactly like the OD97T plug issue that I mentioned on the phone on Wednesday. Please see the attached pics and compare to your glow plug. Basically the top of the plug bottoms out on the head button and not at the seat area at the base of the glow plug stem. Blow-By around the plug reduces the engine compression at even more at peak pressure making it very hard to tune the top-end.
FYI I have spoke to Steve O'Donnell about this issue and it has been addressed. But it is still possible to get old stock which may have this issue.
Now I know why they call you the "engine guru"! Luckily I saved the plugs I used in this engine during all four days of the race and I just checked all of them and they look exactly like the pictures you posted. When I was at the race, I saw all the carbon build-up and figured it was because the engine was running rich, which is why I kept leaning it out. And honestly, I forgot about the issue you mentioned when we spoke about the old OD plugs not seating in the head correctly. Well, live and learn!
What do you suggest I do regarding this plug issue? If you read my post above, I'm obviously not a fan of OS plugs and anyway since the threads on OS plugs and OD plugs differ so much, now I'm afraid of the button leaking if I do switch back to OS plugs. I guess I could buy a new button head to use with the OS plugs, but if you can suggest another brand of plug or know of a way that I can tell the "new" OD plugs from the "old" versions, I'd appreciate any advice you can give me.
I did think about giving you a call on Thursday, but I figured you'd be busy, as well as, stressed out with being in the middle of moving your shop.
Thanks for the quick reply and diagnosing the problem I was having so quickly!
03-15-2011 | 06:13 PM
#1733
Tech Addict
iTrader: (15)
Joined: Jul 2005
Posts: 564
From: AZ
Will - Awesome. I will be at Fear Farm the next two Saturdays if you can make it by.
Ed - NICE!!!
Stubby - At your elevation, make sure you run the 8mm restrictor (not 6mm like we do here in the desert).
Officespace - When I got my first engine I was told that Joe uses the dynamite plugs, so that's what I started with and they work fine. They're about $7 at A-Main. Dynamite #5 Turbo Plug . Since the O'Donnell plugs are a novarossi style plug you may need a new head button to change over.
Ed - NICE!!!
Stubby - At your elevation, make sure you run the 8mm restrictor (not 6mm like we do here in the desert).
Officespace - When I got my first engine I was told that Joe uses the dynamite plugs, so that's what I started with and they work fine. They're about $7 at A-Main. Dynamite #5 Turbo Plug . Since the O'Donnell plugs are a novarossi style plug you may need a new head button to change over.
03-21-2011 | 01:26 AM
#1738
23R Hellfire
Hey guys have just finished breaking in my JS23R, i have pulled the head off just to have a look at things and noticed that there was two aluminium shims but no brass shims! is this normal? I have a JS21 as well, which had one aluminium and two brass shims, and we removed one of the brass shims which realy helped with tune and performance and was going to try the same with the 23R, any info would be greatly appreciated.
Cheers
Scott
Cheers
Scott
03-21-2011 | 12:25 PM
#1739
Hey guys have just finished breaking in my JS23R, i have pulled the head off just to have a look at things and noticed that there was two aluminium shims but no brass shims! is this normal? I have a JS21 as well, which had one aluminium and two brass shims, and we removed one of the brass shims which realy helped with tune and performance and was going to try the same with the 23R, any info would be greatly appreciated.
Cheers
Scott
Cheers
Scott
03-21-2011 | 02:43 PM
#1740
Cheers
Scott