Flick
|
| posted on 29/6/06 at 12:36 AM |
|
|
Blade engine problems
Just finished locost with 98 blade engine. Doesnt seem as fast as ones ive been in before and as revs get upto 6k car starts jerking back and forth.
Dont seem to be able to get above 7k at all. Took it out today and will not go above 70 mph. Just wondered if anyone had come across this before.
Probably a daft question and hope this is just something simple (with a bit of luck) but any help would be appreciated - Thanks
|
|
|
|
|
alister667
|
| posted on 29/6/06 at 12:54 AM |
|
|
Are you running it with the original airbox on?
http://members.lycos.co.uk/alister667/
|
|
|
Flick
|
| posted on 29/6/06 at 01:06 AM |
|
|
No - just borrowed some sock filters and put them on for now as airbox wouldnt fit under bonnet without cutting (had the bonnet on floor and powerfile
in hand but just couldnt do it)
|
|
|
alister667
|
| posted on 29/6/06 at 01:10 AM |
|
|
If running without the airbox you will need to adjust jet size.
To confirm this is the problem, fit the airbox and go for a quick run without the bonnet to see if the problem goes away.
http://members.lycos.co.uk/alister667/
|
|
|
chrisf
|
| posted on 29/6/06 at 03:03 AM |
|
|
This may sound crazy, but a similar issue happened to me. On mine, the tachometer read only half the revs and I bounced off the rev limiter when I got
around 6.5K rpms.
--HTH, Chris
|
|
|
Hellfire
|
| posted on 29/6/06 at 06:51 AM |
|
|
Unusual - did you get a chance to hear the engine running beforehand and was it ok?
Typically it's the wiring that's at fault as 'blade engines twin spark to gain maximum power/efficiency. Check the wiring to the
coils and test the sparks externally on the engine block to confirm this is correct. Check your battery state as this is very important...
'blade engines always like a new set of plugs too when they have been 'wet'.
HTH - Steve
|
|
|
the_fbi
|
| posted on 29/6/06 at 07:24 AM |
|
|
There's that vacuum connection under the carb for cylinder 3 which will cause lean running on 1 cylinder, not sure if having it unblocked would
cause this much lack in performance though.
Revcounter only reading half wouldn't account for a top speed of only 70mph.
You got the choke cable wired up, or the lever fixed in the off position? Any chance your running choke and very rich?
|
|
|
MAB
|
| posted on 29/6/06 at 07:47 AM |
|
|
Flick,
Had exactly the same problem on 2 blade car's I've built. Not running the standard airbox won't help, but you should be able to fix
it by the 'old cocktail stick trick'
ie - blocking up one of the 3 air holes on the top of each of the carbs. I think it is the bottom one but I will check tonight and let you know which
ones as I can't remember right now... You can very easily just block them up with the end of pop rivets...
From what you describe, it sounds exactly the same symptoms.
Mark
|
|
|
alister667
|
| posted on 29/6/06 at 09:28 AM |
|
|
quote:
Originally posted by MAB
Flick,
Had exactly the same problem on 2 blade car's I've built. Not running the standard airbox won't help, but you should be able to fix
it by the 'old cocktail stick trick'
ie - blocking up one of the 3 air holes on the top of each of the carbs. I think it is the bottom one but I will check tonight and let you know which
ones as I can't remember right now... You can very easily just block them up with the end of pop rivets...
From what you describe, it sounds exactly the same symptoms.
Mark
We wound up blocking the middle one and upping the main jets to 132. It's the same mod Stuart Taylor did to their modified carbs to allow them
to run without the airbox. Apparently.
http://members.lycos.co.uk/alister667/
|
|
|
Howlor
|
| posted on 29/6/06 at 09:35 AM |
|
|
Any Pics
|
|
|
ChrisGamlin
|
| posted on 29/6/06 at 11:27 AM |
|
|
Almost certainly running lean I would say, due to lack of airbox and not re-jeting as others have mentioned.
|
|
|
watsonpj
|
| posted on 29/6/06 at 12:00 PM |
|
|
Mine did the same at first once I fitted a dynojet kit it was fine and pulling right up to the red.
|
|
|
alister667
|
| posted on 29/6/06 at 04:37 PM |
|
|
I'm afraid I don't have pictures of it at hand, and my folks have my digital camera.
Sorry.
For what it's worth the engine runs very well on that mod and no bonnet butchery required!
http://members.lycos.co.uk/alister667/
|
|
|
Howlor
|
| posted on 29/6/06 at 07:32 PM |
|
|
When I take off the short trumpets I have 4 brass jets below the main inlet. One far left then 3 together on the right. Two at the top and one in the
middle below these two. Which one should I block off? I will take a picture tonight.
thanks,
Steve
|
|
|
alister667
|
| posted on 29/6/06 at 10:47 PM |
|
|
I *believe* it's the middle one of the three. Does anyone else know for sure? It's been a while since I did this and I'd like a
second opinion!!
http://members.lycos.co.uk/alister667/
|
|
|
