Trap for young (and not so young) players (Long post-sorry. Lot's to say and show)
I've been trying to get this bike running, but all I've managed is to run into problems.
I solved the usual "plastic bag in the tank" problem, so I was getting good flow out of the fuel tap. _/
I then had problems with the bike stumbling at around 4200 RPM, like running out of fuel or air. I made the assumption that my carbs were not as clean as I though, so I pulled them apart again and cleaned them...again. Turns out that the Penetrol I had painted them with sipped into a few crevices. What an IDIOT! Cleaned them throughly...again. In the process I broke a plastic non adjustable float that I was trying to adjust. Luckily I have a spare set of carbs for parts. Save.
Went out for a run and as soon as I opened the throttle the revs went up to around 4000 RPM and would not go down. When I rebuilt carbs the first time I followed Larry Cargill's carb book faithfully. I then had to pull them apart to clean the Penetrol paint that had sipped in and caused the slides to stick. When I put them together I DID NOT follow the book of Larry. I reassembled the bowls and top covers, so I couldn't sit them on the bench to align them properly, so I eyeballed it. They were not well aligned and one or both butterfly valves were sticking open.
I pulled them apart again and this time followed The Good Book....and problem solved.
Today I was able to do a few short runs around the block to dial pilot screws correctly, but it's bogging down as rpm goes up. Again gets up to 4200RPM and bogs down. I tried removing the tank cap in case the vent was blocked. Nope. Check the float levels. Good. WTF ?
I sat in my garage, just looking at the bike for a long time, thinking that after all I've done, I've failed to make the grade. As a novice builder, If I can't get a bike to run, then it's all over. I tried everything I could think off. I knew it was a carb problem but I just couldn't understand what.
Then, just as I was about to walk away, dejected, disheartened and beaten, a thought.....I wander.....Lets give it a go !
My original fuel tap has no filter, so to avoid contamination into carbs, I put an inline filter.
I wondered if the kink in the hose might be restricting fuel flow, especially as revs go up. So I replaced it with just a length of hose and no filter.
Took it for a run, and stumble gone. I'M BACK!
Closing anecdote: I was so happy that I just kept going around the block, until I ran out of fuel about 500m from home, and had to push the bike home. Who cares.
Anyway.........meet
GOLDIE'S LITTLE SISTER (in homage of Cognito Moto's CB750 - One of my favourite builds and the inspiration to mine)
Image out of Pipeburn
In the State I live in, if a vehicle is modified significantly like a whole different front end, then it may have to be assessed by an automotive engineer to enable road registration. I'm taking it to my mechanic for initial assessment and he will tell me if that is so. Until I get registration, I can't ride it. In fact my rides around the block were illegal. But she runs! Keep you posted.