Triumph Sprint Bike Start Attempt

Published on 5 February 2024 at 16:58

I suppose it was always going to be a very low chance of success, there were a lot of unknowns, I didn't even know if the bike had ever been run in it's current configuration, Vic and Adrian had brought the paddock starter over, which span the rear wheel over with great vengeance and furious anger, the magneto was producing a massive spark, the tank was filled with methanol and the first attempt was made.

I would love to report that it fired up straight away and ran like a dream but that would be stretching the truth a bit. I tickled the carbs and it fired once or twice but after several attempts is was clear that something was awry. I thought it had too much advance as on the occasions when it did fire it seemed to be hindering progress rather that aiding it. Vic thought it might be fuel related so we tried starting fluid, which helped a bit, the headers were getting warm, there was definitely combustion going on and it was definitely internal, which is exactly what you want from an internal combustion engine.

I checked the fuel feed from the tank, it's probably marginal as there is very little drop from the outlet to the carbs but it's how George Cole ran it so I guessed it was ok. We tried tilting the carbs down, that seemed too help a little, probably raised the height of the fuel in the bowl a bit.

The thing that really made a difference is when we simulated a choke by Vic putting his hand over one carb inlet while I blocked off the other. It actually ran and revved -  great, that eliminated many things and pointed very much to the fuelling. To prove the point we got a couple of air filters - one that was lying about on the side and one off my gpz1100 chopper, that gave us the best running so far. It's far from being right but it did start, it did run, it did rev, I think the idle jets are too small, I still think it may have a touch too much advance but at least it's running enough to mess about with these things now. I need to carry on and get my starter built, the one Vic has cost a fortune, I don't have that  spare cash right now and given all the help he had given me it would have been rude to mug him.

I need to refresh my memory and see what size idle jets are in there at the moment and get some bigger ones, some time this week I will reset the timing to about 42 -44 degrees btdc and leave it there until I have my rollers finished.

I have a stinking cold and feel horrible, I got a bit of metal in my eye last week so my vision is still blurry. I am very happy with where things are for now but a couple of days rest in front of the fire seems appealing right now. Massive thanks again to Adrian and Vic, I could not have got this far without your help. Videopoo here

Add comment


There are no comments yet.