New to B4...SPU issues...leaks and all the rest -
LinkBack Thread Tools Display Modes
post #1 of 4 (permalink) Old 08-17-2016, 03:35 PM Thread Starter
New Member
Join Date: Jun 2016
Posts: 2
New to B4...SPU issues...leaks and all the rest

Hello fellow masochists

Having had a Duc748s with all it's idiosyncrasies stolen, I couldn't believe my luck when I saw a B4 750 up for grabs across the other side of the country.

had to drive her home 5 hours and fell in love with the whole package. For the first time in modern times, it felt like a company had managed to build a 4 stroke engine that acted like a 2 stroke and sounded like a 60s ferrari with an induction roar to die for.

Since then, reality has struck with some rather odd happenings.
from running sweet she suddenly out of nowhere went onto 2 cylinders...
As the dealer had written the bike was serviced I didn't think this would be a bit of a pork pie, so having removed everything electrical, checked it and put them back, I then measured the spark plug resistences and they were all too low... So in with the best Iridium plugs I could get and she was off on four again. Was also given feedback to not use 95 fuel, but 98 (I'm in sweden...).
During the work over I ripped out the PC3 at the same time as I was also given the tip to remove this... I then managed to download an update which killed it...well, there you go.

She was going well again when a week later after some really heavy rain I parked up the bike. next morning the Deka battery (new) was completely dead... So I put on charge for 24 hours and tried again. Took her out , when I killed the ignition she kept running...SPU, blue backed..cigg burns in the blue...had kept the fuel primer relay running all night I guess that killed the battery.

So, gutted but knowing at least what the issue was, I found a second hand replacement in Italy. had to wait a week....plugged it in..and yes, obviously everything works except the headlight....wrong SPU/CDI.. I obviously need the 8A00A9615 but received the 8A00A9300 version. So the bloke is checking if he has a 615..
And now, for some reason, the bike isn't wanting to rev past around 8000/9000 rpm. The last time the fuel filter was changed was 2012 according to receipts I got with the bike of previous I'm guessing this will require hoses, clamps, filter and O-seal to sort out.

Also have a oil weep under the right side this normal..? could it require a new oil seal....

So, just like to thank this .net as I had to get on the net to research all the issues as I want to keep this bike, it's frikken awesome. So great with all the info. //N
Gonzo67 is offline  
Sponsored Links
post #2 of 4 (permalink) Old 08-17-2016, 03:57 PM
Established Member
biaggi's Avatar
Join Date: Feb 2013
Location: London, England
Posts: 178
Hi and welcome.

Before doing anything I'd get the SPU sorted and then see if it still runs poorly/won't rev beyond 8/9K.

Interesting to read what you say about the headlight as I have the same issue with a new SPU and have gone back to the supplier for their advice.

The oil weep on the right - do you mean the main right cover that has the oil filler cap? If so that's the clutch cover and you might need a new gasket if so.

You won't need to do a full oil drain if you put it on the side stand but some will come out so be ready to capture it and top back up afterwards.

If you like the sound, get an arrow link pipe and remove the horrible, ugly and heavy cat box. The sound is then so awesome you'll ride around in 3rd or 4th gear just for the fun of it.

biaggi is offline  
post #3 of 4 (permalink) Old 08-18-2016, 04:17 PM Thread Starter
New Member
Join Date: Jun 2016
Posts: 2
yep, the heavy cat box has gone and replaced by a Corse link pipe which came with a BMC filter. Standard pipes left on it but apparently the arrow ends aren't that much louder anyway..sounds awesome.
I'm now sourcing the correct SPU.
Next up on the agenda is to change the fuel lines, fuel filter in the tank. probably won't do any harm.
The oil is weeping on the left hand side at the cover where you would do the timing. Just a gasket I guess and some silicone will fix.
Once again, great to do the research on this site, so many tips and info which saves a lot of time.
Gonzo67 is offline  
Sponsored Links
post #4 of 4 (permalink) Old 08-19-2016, 01:00 AM
Established Member
biaggi's Avatar
Join Date: Feb 2013
Location: London, England
Posts: 178
Yes there's a rubber o-ring in that cover so quick and easy to replace or reseal with some flexible gasket sealant.
biaggi is offline  

Quick Reply

Register Now

In order to use all of the features of the site, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome