Carburettor synchronisation

petrolhead · Post by **petrolhead** » Sun Aug 24, 2003 10:22 am

Hi, just wanted to ask if anybody has got some experience with the Carbtune II instrument?

I was thinking about buying one, but am uncertain. I also have a Triumph Bonnie 650 -67 model which requires frequent synchronisation, so it will also be used for that. I see that it gets good reviews.

Thanks for any comments...

thetyrant · Post by **thetyrant** » Sun Aug 24, 2003 11:21 am

I have one of the original John Morgan Carbtune wid Mercury in them...works fine although a little toxic if yer not carefull. Sure the new one will be just a good.

Cheers

Ian

petrolhead · Post by **petrolhead** » Sun Aug 24, 2003 7:59 pm

OK, looks like I have to give them a ring and order a set

. IÂ´ll let you know when I have synchronised my carbs.

bfs · Post by **bfs** » Sun Aug 31, 2003 7:18 pm

If you haven't bought the carbtune yet, then I can positively recommend the Davida dial vacuum gauge. I've just bought one and it works great. I've been told that the newer carbtune with the stainless steel rods get stuck sometimes....

petrolhead · Post by **petrolhead** » Sun Aug 31, 2003 9:38 pm

Thank you for the advice, but I ordered the Carbtune on Wednesday and received them in my briefcase on Saturday. HavenÂ´t tried them yet, but you have to keep them vertical so that the rods donÂ´t get additional friction from the guides I think... Anyway had only the guys I ordered the other parts from had the same mail order service...

petrolhead · Post by **petrolhead** » Sun Sep 07, 2003 5:59 pm

I used my new Carbtune today

.
Easy to set up and use, but I experienced that the readings (taken from the same cylinder) altered from column to column, so that you have to take that into account when you synchronise the carbs. I.e if you just synchronise the carbs and do not check it changing the tubes / columns on the Carbtune it can be that the result will not be correct or any better than before the synchronisation.

This is how it looked after synchronisation.
All readings taken at 1100RPM.
Front sylinder on column 1 (left) and rear cylinder on column 2.

After changing the tubes / columns on the Carbtune.
Now rear cylinder on column 1 and front cylinder on column 2.

The difference in the readings must have something to do with the calibration of the Carbtune, and must be adjusted for when synchronising.

I then wrote down the readings and adjusted it so that the readings were similar on the same column and cylinder after changing them.

The picture shows front cylinder on column 1.
(rear cylinder on column 2)

The picture shows rear cylnder on column 1.
(front cylinder on column 2)

I hope my explanation is possible to understand, otherwise please excuse my poor English.

delmeekc · Post by **delmeekc** » Sun Sep 07, 2003 6:28 pm

Gowd, they is poo. I have the dial type gauges and when you swap them around they are exactly the same. Are they new.

Del.

petrolhead · Post by **petrolhead** » Sun Sep 07, 2003 7:24 pm

Yes, brand new out of the box, first time it is used. What brand / price is yours?

delmeekc · Post by **delmeekc** » Mon Sep 08, 2003 9:13 pm

They is Davida Moto (Dail type), got em from M&P I think a good few years ago.

Del.

petrolhead · Post by **petrolhead** » Sun Sep 21, 2003 11:14 am

I contacted Carbtune and their reply can be read below.
Very correctly they refunded me the cost of the Carbtune.
Good service.
----------------------
Thanks for your email and sorry for the problem with your Carbtune. We sell thousands of the Carbtune and it is very rare that we have any problems with them. Probably a few a year. We are human and occasionally make mistakes in the assembly. Sometimes it's damaged in the post. It is very rare but you just got a faulty one. Sorry.
If you look at the website you will see that random samples of the Carbtune have been tested in an independent testing laboratory and were the most accurate multi-gauge device tested. More accurate than any dial gauges, even expensive ones.

Atkinspa · Post by **Atkinspa** » Sun Oct 12, 2003 10:22 pm

I have used carbtune on a number of 4cyl bikes with no problems. Found it easier personaly to use than a dial gauge, althought thats down to personal tast. I have not tried it on the the Storm. I have just overhauled the carbs and installed a dynojet kit I must give it a try when I get them back together.